| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.commons.lang; |
| |
| import java.util.ArrayList; |
| import java.util.Collection; |
| import java.util.Iterator; |
| import java.util.List; |
| |
| /** |
| * <p>Operations on {@link java.lang.String} that are |
| * <code>null</code> safe.</p> |
| * |
| * <ul> |
| * <li><b>IsEmpty/IsBlank</b> |
| * - checks if a String contains text</li> |
| * <li><b>Trim/Strip</b> |
| * - removes leading and trailing whitespace</li> |
| * <li><b>Equals</b> |
| * - compares two strings null-safe</li> |
| * <li><b>IndexOf/LastIndexOf/Contains</b> |
| * - null-safe index-of checks |
| * <li><b>IndexOfAny/LastIndexOfAny/IndexOfAnyBut/LastIndexOfAnyBut</b> |
| * - index-of any of a set of Strings</li> |
| * <li><b>ContainsOnly/ContainsNone</b> |
| * - does String contains only/none of these characters</li> |
| * <li><b>Substring/Left/Right/Mid</b> |
| * - null-safe substring extractions</li> |
| * <li><b>SubstringBefore/SubstringAfter/SubstringBetween</b> |
| * - substring extraction relative to other strings</li> |
| * <li><b>Split/Join</b> |
| * - splits a String into an array of substrings and vice versa</li> |
| * <li><b>Remove/Delete</b> |
| * - removes part of a String</li> |
| * <li><b>Replace/Overlay</b> |
| * - Searches a String and replaces one String with another</li> |
| * <li><b>Chomp/Chop</b> |
| * - removes the last part of a String</li> |
| * <li><b>LeftPad/RightPad/Center/Repeat</b> |
| * - pads a String</li> |
| * <li><b>UpperCase/LowerCase/SwapCase/Capitalize/Uncapitalize</b> |
| * - changes the case of a String</li> |
| * <li><b>CountMatches</b> |
| * - counts the number of occurrences of one String in another</li> |
| * <li><b>IsAlpha/IsNumeric/IsWhitespace/IsAsciiPrintable</b> |
| * - checks the characters in a String</li> |
| * <li><b>DefaultString</b> |
| * - protects against a null input String</li> |
| * <li><b>Reverse/ReverseDelimited</b> |
| * - reverses a String</li> |
| * <li><b>Abbreviate</b> |
| * - abbreviates a string using ellipsis</li> |
| * <li><b>Difference</b> |
| * - compares two Strings and reports on their differences</li> |
| * <li><b>LevensteinDistance</b> |
| * - the number of changes needed to change one String into another</li> |
| * </ul> |
| * |
| * <p>The <code>StringUtils</code> class defines certain words related to |
| * String handling.</p> |
| * |
| * <ul> |
| * <li>null - <code>null</code></li> |
| * <li>empty - a zero-length string (<code>""</code>)</li> |
| * <li>space - the space character (<code>' '</code>, char 32)</li> |
| * <li>whitespace - the characters defined by {@link Character#isWhitespace(char)}</li> |
| * <li>trim - the characters <= 32 as in {@link String#trim()}</li> |
| * </ul> |
| * |
| * <p><code>StringUtils</code> handles <code>null</code> input Strings quietly. |
| * That is to say that a <code>null</code> input will return <code>null</code>. |
| * Where a <code>boolean</code> or <code>int</code> is being returned |
| * details vary by method.</p> |
| * |
| * <p>A side effect of the <code>null</code> handling is that a |
| * <code>NullPointerException</code> should be considered a bug in |
| * <code>StringUtils</code> (except for deprecated methods).</p> |
| * |
| * <p>Methods in this class give sample code to explain their operation. |
| * The symbol <code>*</code> is used to indicate any input including <code>null</code>.</p> |
| * |
| * @see java.lang.String |
| * @author <a href="http://jakarta.apache.org/turbine/">Apache Jakarta Turbine</a> |
| * @author <a href="mailto:jon@latchkey.com">Jon S. Stevens</a> |
| * @author <a href="mailto:dlr@finemaltcoding.com">Daniel Rall</a> |
| * @author <a href="mailto:gcoladonato@yahoo.com">Greg Coladonato</a> |
| * @author <a href="mailto:ed@apache.org">Ed Korthof</a> |
| * @author <a href="mailto:rand_mcneely@yahoo.com">Rand McNeely</a> |
| * @author Stephen Colebourne |
| * @author <a href="mailto:fredrik@westermarck.com">Fredrik Westermarck</a> |
| * @author Holger Krauth |
| * @author <a href="mailto:alex@purpletech.com">Alexander Day Chaffee</a> |
| * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a> |
| * @author Arun Mammen Thomas |
| * @author Gary Gregory |
| * @author Phil Steitz |
| * @author Al Chou |
| * @author Michael Davey |
| * @author Reuben Sivan |
| * @author Chris Hyzer |
| * @since 1.0 |
| * @version $Id$ |
| */ |
| public class StringUtils { |
| // Performance testing notes (JDK 1.4, Jul03, scolebourne) |
| // Whitespace: |
| // Character.isWhitespace() is faster than WHITESPACE.indexOf() |
| // where WHITESPACE is a string of all whitespace characters |
| // |
| // Character access: |
| // String.charAt(n) versus toCharArray(), then array[n] |
| // String.charAt(n) is about 15% worse for a 10K string |
| // They are about equal for a length 50 string |
| // String.charAt(n) is about 4 times better for a length 3 string |
| // String.charAt(n) is best bet overall |
| // |
| // Append: |
| // String.concat about twice as fast as StringBuffer.append |
| // (not sure who tested this) |
| |
| /** |
| * The empty String <code>""</code>. |
| * @since 2.0 |
| */ |
| public static final String EMPTY = ""; |
| |
| /** |
| * Represents a failed index search. |
| * @since 2.1 |
| */ |
| public static final int INDEX_NOT_FOUND = -1; |
| |
| /** |
| * <p>The maximum size to which the padding constant(s) can expand.</p> |
| */ |
| private static final int PAD_LIMIT = 8192; |
| |
| /** |
| * <p><code>StringUtils</code> instances should NOT be constructed in |
| * standard programming. Instead, the class should be used as |
| * <code>StringUtils.trim(" foo ");</code>.</p> |
| * |
| * <p>This constructor is public to permit tools that require a JavaBean |
| * instance to operate.</p> |
| */ |
| public StringUtils() { |
| super(); |
| } |
| |
| // Empty checks |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Checks if a String is empty ("") or null.</p> |
| * |
| * <pre> |
| * StringUtils.isEmpty(null) = true |
| * StringUtils.isEmpty("") = true |
| * StringUtils.isEmpty(" ") = false |
| * StringUtils.isEmpty("bob") = false |
| * StringUtils.isEmpty(" bob ") = false |
| * </pre> |
| * |
| * <p>NOTE: This method changed in Lang version 2.0. |
| * It no longer trims the String. |
| * That functionality is available in isBlank().</p> |
| * |
| * @param str the String to check, may be null |
| * @return <code>true</code> if the String is empty or null |
| */ |
| public static boolean isEmpty(String str) { |
| return str == null || str.length() == 0; |
| } |
| |
| /** |
| * <p>Checks if a String is not empty ("") and not null.</p> |
| * |
| * <pre> |
| * StringUtils.isNotEmpty(null) = false |
| * StringUtils.isNotEmpty("") = false |
| * StringUtils.isNotEmpty(" ") = true |
| * StringUtils.isNotEmpty("bob") = true |
| * StringUtils.isNotEmpty(" bob ") = true |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @return <code>true</code> if the String is not empty and not null |
| */ |
| public static boolean isNotEmpty(String str) { |
| return !StringUtils.isEmpty(str); |
| } |
| |
| /** |
| * <p>Checks if a String is whitespace, empty ("") or null.</p> |
| * |
| * <pre> |
| * StringUtils.isBlank(null) = true |
| * StringUtils.isBlank("") = true |
| * StringUtils.isBlank(" ") = true |
| * StringUtils.isBlank("bob") = false |
| * StringUtils.isBlank(" bob ") = false |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @return <code>true</code> if the String is null, empty or whitespace |
| * @since 2.0 |
| */ |
| public static boolean isBlank(String str) { |
| int strLen; |
| if (str == null || (strLen = str.length()) == 0) { |
| return true; |
| } |
| for (int i = 0; i < strLen; i++) { |
| if ((Character.isWhitespace(str.charAt(i)) == false)) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| /** |
| * <p>Checks if a String is not empty (""), not null and not whitespace only.</p> |
| * |
| * <pre> |
| * StringUtils.isNotBlank(null) = false |
| * StringUtils.isNotBlank("") = false |
| * StringUtils.isNotBlank(" ") = false |
| * StringUtils.isNotBlank("bob") = true |
| * StringUtils.isNotBlank(" bob ") = true |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @return <code>true</code> if the String is |
| * not empty and not null and not whitespace |
| * @since 2.0 |
| */ |
| public static boolean isNotBlank(String str) { |
| return !StringUtils.isBlank(str); |
| } |
| |
| // Trim |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Removes control characters (char <= 32) from both |
| * ends of this String, handling <code>null</code> by returning |
| * an empty String ("").</p> |
| * |
| * <pre> |
| * StringUtils.clean(null) = "" |
| * StringUtils.clean("") = "" |
| * StringUtils.clean("abc") = "abc" |
| * StringUtils.clean(" abc ") = "abc" |
| * StringUtils.clean(" ") = "" |
| * </pre> |
| * |
| * @see java.lang.String#trim() |
| * @param str the String to clean, may be null |
| * @return the trimmed text, never <code>null</code> |
| * @deprecated Use the clearer named {@link #trimToEmpty(String)}. |
| * Method will be removed in Commons Lang 3.0. |
| */ |
| public static String clean(String str) { |
| return str == null ? EMPTY : str.trim(); |
| } |
| |
| /** |
| * <p>Removes control characters (char <= 32) from both |
| * ends of this String, handling <code>null</code> by returning |
| * <code>null</code>.</p> |
| * |
| * <p>The String is trimmed using {@link String#trim()}. |
| * Trim removes start and end characters <= 32. |
| * To strip whitespace use {@link #strip(String)}.</p> |
| * |
| * <p>To trim your choice of characters, use the |
| * {@link #strip(String, String)} methods.</p> |
| * |
| * <pre> |
| * StringUtils.trim(null) = null |
| * StringUtils.trim("") = "" |
| * StringUtils.trim(" ") = "" |
| * StringUtils.trim("abc") = "abc" |
| * StringUtils.trim(" abc ") = "abc" |
| * </pre> |
| * |
| * @param str the String to be trimmed, may be null |
| * @return the trimmed string, <code>null</code> if null String input |
| */ |
| public static String trim(String str) { |
| return str == null ? null : str.trim(); |
| } |
| |
| /** |
| * <p>Removes control characters (char <= 32) from both |
| * ends of this String returning <code>null</code> if the String is |
| * empty ("") after the trim or if it is <code>null</code>. |
| * |
| * <p>The String is trimmed using {@link String#trim()}. |
| * Trim removes start and end characters <= 32. |
| * To strip whitespace use {@link #stripToNull(String)}.</p> |
| * |
| * <pre> |
| * StringUtils.trimToNull(null) = null |
| * StringUtils.trimToNull("") = null |
| * StringUtils.trimToNull(" ") = null |
| * StringUtils.trimToNull("abc") = "abc" |
| * StringUtils.trimToNull(" abc ") = "abc" |
| * </pre> |
| * |
| * @param str the String to be trimmed, may be null |
| * @return the trimmed String, |
| * <code>null</code> if only chars <= 32, empty or null String input |
| * @since 2.0 |
| */ |
| public static String trimToNull(String str) { |
| String ts = trim(str); |
| return isEmpty(ts) ? null : ts; |
| } |
| |
| /** |
| * <p>Removes control characters (char <= 32) from both |
| * ends of this String returning an empty String ("") if the String |
| * is empty ("") after the trim or if it is <code>null</code>. |
| * |
| * <p>The String is trimmed using {@link String#trim()}. |
| * Trim removes start and end characters <= 32. |
| * To strip whitespace use {@link #stripToEmpty(String)}.</p> |
| * |
| * <pre> |
| * StringUtils.trimToEmpty(null) = "" |
| * StringUtils.trimToEmpty("") = "" |
| * StringUtils.trimToEmpty(" ") = "" |
| * StringUtils.trimToEmpty("abc") = "abc" |
| * StringUtils.trimToEmpty(" abc ") = "abc" |
| * </pre> |
| * |
| * @param str the String to be trimmed, may be null |
| * @return the trimmed String, or an empty String if <code>null</code> input |
| * @since 2.0 |
| */ |
| public static String trimToEmpty(String str) { |
| return str == null ? EMPTY : str.trim(); |
| } |
| |
| // Stripping |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Strips whitespace from the start and end of a String.</p> |
| * |
| * <p>This is similar to {@link #trim(String)} but removes whitespace. |
| * Whitespace is defined by {@link Character#isWhitespace(char)}.</p> |
| * |
| * <p>A <code>null</code> input String returns <code>null</code>.</p> |
| * |
| * <pre> |
| * StringUtils.strip(null) = null |
| * StringUtils.strip("") = "" |
| * StringUtils.strip(" ") = "" |
| * StringUtils.strip("abc") = "abc" |
| * StringUtils.strip(" abc") = "abc" |
| * StringUtils.strip("abc ") = "abc" |
| * StringUtils.strip(" abc ") = "abc" |
| * StringUtils.strip(" ab c ") = "ab c" |
| * </pre> |
| * |
| * @param str the String to remove whitespace from, may be null |
| * @return the stripped String, <code>null</code> if null String input |
| */ |
| public static String strip(String str) { |
| return strip(str, null); |
| } |
| |
| /** |
| * <p>Strips whitespace from the start and end of a String returning |
| * <code>null</code> if the String is empty ("") after the strip.</p> |
| * |
| * <p>This is similar to {@link #trimToNull(String)} but removes whitespace. |
| * Whitespace is defined by {@link Character#isWhitespace(char)}.</p> |
| * |
| * <pre> |
| * StringUtils.stripToNull(null) = null |
| * StringUtils.stripToNull("") = null |
| * StringUtils.stripToNull(" ") = null |
| * StringUtils.stripToNull("abc") = "abc" |
| * StringUtils.stripToNull(" abc") = "abc" |
| * StringUtils.stripToNull("abc ") = "abc" |
| * StringUtils.stripToNull(" abc ") = "abc" |
| * StringUtils.stripToNull(" ab c ") = "ab c" |
| * </pre> |
| * |
| * @param str the String to be stripped, may be null |
| * @return the stripped String, |
| * <code>null</code> if whitespace, empty or null String input |
| * @since 2.0 |
| */ |
| public static String stripToNull(String str) { |
| if (str == null) { |
| return null; |
| } |
| str = strip(str, null); |
| return str.length() == 0 ? null : str; |
| } |
| |
| /** |
| * <p>Strips whitespace from the start and end of a String returning |
| * an empty String if <code>null</code> input.</p> |
| * |
| * <p>This is similar to {@link #trimToEmpty(String)} but removes whitespace. |
| * Whitespace is defined by {@link Character#isWhitespace(char)}.</p> |
| * |
| * <pre> |
| * StringUtils.stripToEmpty(null) = "" |
| * StringUtils.stripToEmpty("") = "" |
| * StringUtils.stripToEmpty(" ") = "" |
| * StringUtils.stripToEmpty("abc") = "abc" |
| * StringUtils.stripToEmpty(" abc") = "abc" |
| * StringUtils.stripToEmpty("abc ") = "abc" |
| * StringUtils.stripToEmpty(" abc ") = "abc" |
| * StringUtils.stripToEmpty(" ab c ") = "ab c" |
| * </pre> |
| * |
| * @param str the String to be stripped, may be null |
| * @return the trimmed String, or an empty String if <code>null</code> input |
| * @since 2.0 |
| */ |
| public static String stripToEmpty(String str) { |
| return str == null ? EMPTY : strip(str, null); |
| } |
| |
| /** |
| * <p>Strips any of a set of characters from the start and end of a String. |
| * This is similar to {@link String#trim()} but allows the characters |
| * to be stripped to be controlled.</p> |
| * |
| * <p>A <code>null</code> input String returns <code>null</code>. |
| * An empty string ("") input returns the empty string.</p> |
| * |
| * <p>If the stripChars String is <code>null</code>, whitespace is |
| * stripped as defined by {@link Character#isWhitespace(char)}. |
| * Alternatively use {@link #strip(String)}.</p> |
| * |
| * <pre> |
| * StringUtils.strip(null, *) = null |
| * StringUtils.strip("", *) = "" |
| * StringUtils.strip("abc", null) = "abc" |
| * StringUtils.strip(" abc", null) = "abc" |
| * StringUtils.strip("abc ", null) = "abc" |
| * StringUtils.strip(" abc ", null) = "abc" |
| * StringUtils.strip(" abcyx", "xyz") = " abc" |
| * </pre> |
| * |
| * @param str the String to remove characters from, may be null |
| * @param stripChars the characters to remove, null treated as whitespace |
| * @return the stripped String, <code>null</code> if null String input |
| */ |
| public static String strip(String str, String stripChars) { |
| if (isEmpty(str)) { |
| return str; |
| } |
| str = stripStart(str, stripChars); |
| return stripEnd(str, stripChars); |
| } |
| |
| /** |
| * <p>Strips any of a set of characters from the start of a String.</p> |
| * |
| * <p>A <code>null</code> input String returns <code>null</code>. |
| * An empty string ("") input returns the empty string.</p> |
| * |
| * <p>If the stripChars String is <code>null</code>, whitespace is |
| * stripped as defined by {@link Character#isWhitespace(char)}.</p> |
| * |
| * <pre> |
| * StringUtils.stripStart(null, *) = null |
| * StringUtils.stripStart("", *) = "" |
| * StringUtils.stripStart("abc", "") = "abc" |
| * StringUtils.stripStart("abc", null) = "abc" |
| * StringUtils.stripStart(" abc", null) = "abc" |
| * StringUtils.stripStart("abc ", null) = "abc " |
| * StringUtils.stripStart(" abc ", null) = "abc " |
| * StringUtils.stripStart("yxabc ", "xyz") = "abc " |
| * </pre> |
| * |
| * @param str the String to remove characters from, may be null |
| * @param stripChars the characters to remove, null treated as whitespace |
| * @return the stripped String, <code>null</code> if null String input |
| */ |
| public static String stripStart(String str, String stripChars) { |
| int strLen; |
| if (str == null || (strLen = str.length()) == 0) { |
| return str; |
| } |
| int start = 0; |
| if (stripChars == null) { |
| while ((start != strLen) && Character.isWhitespace(str.charAt(start))) { |
| start++; |
| } |
| } else if (stripChars.length() == 0) { |
| return str; |
| } else { |
| while ((start != strLen) && (stripChars.indexOf(str.charAt(start)) != -1)) { |
| start++; |
| } |
| } |
| return str.substring(start); |
| } |
| |
| /** |
| * <p>Strips any of a set of characters from the end of a String.</p> |
| * |
| * <p>A <code>null</code> input String returns <code>null</code>. |
| * An empty string ("") input returns the empty string.</p> |
| * |
| * <p>If the stripChars String is <code>null</code>, whitespace is |
| * stripped as defined by {@link Character#isWhitespace(char)}.</p> |
| * |
| * <pre> |
| * StringUtils.stripEnd(null, *) = null |
| * StringUtils.stripEnd("", *) = "" |
| * StringUtils.stripEnd("abc", "") = "abc" |
| * StringUtils.stripEnd("abc", null) = "abc" |
| * StringUtils.stripEnd(" abc", null) = " abc" |
| * StringUtils.stripEnd("abc ", null) = "abc" |
| * StringUtils.stripEnd(" abc ", null) = " abc" |
| * StringUtils.stripEnd(" abcyx", "xyz") = " abc" |
| * </pre> |
| * |
| * @param str the String to remove characters from, may be null |
| * @param stripChars the characters to remove, null treated as whitespace |
| * @return the stripped String, <code>null</code> if null String input |
| */ |
| public static String stripEnd(String str, String stripChars) { |
| int end; |
| if (str == null || (end = str.length()) == 0) { |
| return str; |
| } |
| |
| if (stripChars == null) { |
| while ((end != 0) && Character.isWhitespace(str.charAt(end - 1))) { |
| end--; |
| } |
| } else if (stripChars.length() == 0) { |
| return str; |
| } else { |
| while ((end != 0) && (stripChars.indexOf(str.charAt(end - 1)) != -1)) { |
| end--; |
| } |
| } |
| return str.substring(0, end); |
| } |
| |
| // StripAll |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Strips whitespace from the start and end of every String in an array. |
| * Whitespace is defined by {@link Character#isWhitespace(char)}.</p> |
| * |
| * <p>A new array is returned each time, except for length zero. |
| * A <code>null</code> array will return <code>null</code>. |
| * An empty array will return itself. |
| * A <code>null</code> array entry will be ignored.</p> |
| * |
| * <pre> |
| * StringUtils.stripAll(null) = null |
| * StringUtils.stripAll([]) = [] |
| * StringUtils.stripAll(["abc", " abc"]) = ["abc", "abc"] |
| * StringUtils.stripAll(["abc ", null]) = ["abc", null] |
| * </pre> |
| * |
| * @param strs the array to remove whitespace from, may be null |
| * @return the stripped Strings, <code>null</code> if null array input |
| */ |
| public static String[] stripAll(String[] strs) { |
| return stripAll(strs, null); |
| } |
| |
| /** |
| * <p>Strips any of a set of characters from the start and end of every |
| * String in an array.</p> |
| * Whitespace is defined by {@link Character#isWhitespace(char)}.</p> |
| * |
| * <p>A new array is returned each time, except for length zero. |
| * A <code>null</code> array will return <code>null</code>. |
| * An empty array will return itself. |
| * A <code>null</code> array entry will be ignored. |
| * A <code>null</code> stripChars will strip whitespace as defined by |
| * {@link Character#isWhitespace(char)}.</p> |
| * |
| * <pre> |
| * StringUtils.stripAll(null, *) = null |
| * StringUtils.stripAll([], *) = [] |
| * StringUtils.stripAll(["abc", " abc"], null) = ["abc", "abc"] |
| * StringUtils.stripAll(["abc ", null], null) = ["abc", null] |
| * StringUtils.stripAll(["abc ", null], "yz") = ["abc ", null] |
| * StringUtils.stripAll(["yabcz", null], "yz") = ["abc", null] |
| * </pre> |
| * |
| * @param strs the array to remove characters from, may be null |
| * @param stripChars the characters to remove, null treated as whitespace |
| * @return the stripped Strings, <code>null</code> if null array input |
| */ |
| public static String[] stripAll(String[] strs, String stripChars) { |
| int strsLen; |
| if (strs == null || (strsLen = strs.length) == 0) { |
| return strs; |
| } |
| String[] newArr = new String[strsLen]; |
| for (int i = 0; i < strsLen; i++) { |
| newArr[i] = strip(strs[i], stripChars); |
| } |
| return newArr; |
| } |
| |
| // Equals |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Compares two Strings, returning <code>true</code> if they are equal.</p> |
| * |
| * <p><code>null</code>s are handled without exceptions. Two <code>null</code> |
| * references are considered to be equal. The comparison is case sensitive.</p> |
| * |
| * <pre> |
| * StringUtils.equals(null, null) = true |
| * StringUtils.equals(null, "abc") = false |
| * StringUtils.equals("abc", null) = false |
| * StringUtils.equals("abc", "abc") = true |
| * StringUtils.equals("abc", "ABC") = false |
| * </pre> |
| * |
| * @see java.lang.String#equals(Object) |
| * @param str1 the first String, may be null |
| * @param str2 the second String, may be null |
| * @return <code>true</code> if the Strings are equal, case sensitive, or |
| * both <code>null</code> |
| */ |
| public static boolean equals(String str1, String str2) { |
| return str1 == null ? str2 == null : str1.equals(str2); |
| } |
| |
| /** |
| * <p>Compares two Strings, returning <code>true</code> if they are equal ignoring |
| * the case.</p> |
| * |
| * <p><code>null</code>s are handled without exceptions. Two <code>null</code> |
| * references are considered equal. Comparison is case insensitive.</p> |
| * |
| * <pre> |
| * StringUtils.equalsIgnoreCase(null, null) = true |
| * StringUtils.equalsIgnoreCase(null, "abc") = false |
| * StringUtils.equalsIgnoreCase("abc", null) = false |
| * StringUtils.equalsIgnoreCase("abc", "abc") = true |
| * StringUtils.equalsIgnoreCase("abc", "ABC") = true |
| * </pre> |
| * |
| * @see java.lang.String#equalsIgnoreCase(String) |
| * @param str1 the first String, may be null |
| * @param str2 the second String, may be null |
| * @return <code>true</code> if the Strings are equal, case insensitive, or |
| * both <code>null</code> |
| */ |
| public static boolean equalsIgnoreCase(String str1, String str2) { |
| return str1 == null ? str2 == null : str1.equalsIgnoreCase(str2); |
| } |
| |
| // IndexOf |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Finds the first index within a String, handling <code>null</code>. |
| * This method uses {@link String#indexOf(int)}.</p> |
| * |
| * <p>A <code>null</code> or empty ("") String will return <code>-1</code>.</p> |
| * |
| * <pre> |
| * StringUtils.indexOf(null, *) = -1 |
| * StringUtils.indexOf("", *) = -1 |
| * StringUtils.indexOf("aabaabaa", 'a') = 0 |
| * StringUtils.indexOf("aabaabaa", 'b') = 2 |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @param searchChar the character to find |
| * @return the first index of the search character, |
| * -1 if no match or <code>null</code> string input |
| * @since 2.0 |
| */ |
| public static int indexOf(String str, char searchChar) { |
| if (isEmpty(str)) { |
| return -1; |
| } |
| return str.indexOf(searchChar); |
| } |
| |
| /** |
| * <p>Finds the first index within a String from a start position, |
| * handling <code>null</code>. |
| * This method uses {@link String#indexOf(int, int)}.</p> |
| * |
| * <p>A <code>null</code> or empty ("") String will return <code>-1</code>. |
| * A negative start position is treated as zero. |
| * A start position greater than the string length returns <code>-1</code>.</p> |
| * |
| * <pre> |
| * StringUtils.indexOf(null, *, *) = -1 |
| * StringUtils.indexOf("", *, *) = -1 |
| * StringUtils.indexOf("aabaabaa", 'b', 0) = 2 |
| * StringUtils.indexOf("aabaabaa", 'b', 3) = 5 |
| * StringUtils.indexOf("aabaabaa", 'b', 9) = -1 |
| * StringUtils.indexOf("aabaabaa", 'b', -1) = 2 |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @param searchChar the character to find |
| * @param startPos the start position, negative treated as zero |
| * @return the first index of the search character, |
| * -1 if no match or <code>null</code> string input |
| * @since 2.0 |
| */ |
| public static int indexOf(String str, char searchChar, int startPos) { |
| if (isEmpty(str)) { |
| return -1; |
| } |
| return str.indexOf(searchChar, startPos); |
| } |
| |
| /** |
| * <p>Finds the first index within a String, handling <code>null</code>. |
| * This method uses {@link String#indexOf(String)}.</p> |
| * |
| * <p>A <code>null</code> String will return <code>-1</code>.</p> |
| * |
| * <pre> |
| * StringUtils.indexOf(null, *) = -1 |
| * StringUtils.indexOf(*, null) = -1 |
| * StringUtils.indexOf("", "") = 0 |
| * StringUtils.indexOf("aabaabaa", "a") = 0 |
| * StringUtils.indexOf("aabaabaa", "b") = 2 |
| * StringUtils.indexOf("aabaabaa", "ab") = 1 |
| * StringUtils.indexOf("aabaabaa", "") = 0 |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @param searchStr the String to find, may be null |
| * @return the first index of the search String, |
| * -1 if no match or <code>null</code> string input |
| * @since 2.0 |
| */ |
| public static int indexOf(String str, String searchStr) { |
| if (str == null || searchStr == null) { |
| return -1; |
| } |
| return str.indexOf(searchStr); |
| } |
| |
| /** |
| * <p>Finds the n-th index within a String, handling <code>null</code>. |
| * This method uses {@link String#indexOf(String)}.</p> |
| * |
| * <p>A <code>null</code> String will return <code>-1</code>.</p> |
| * |
| * <pre> |
| * StringUtils.ordinalIndexOf(null, *, *) = -1 |
| * StringUtils.ordinalIndexOf(*, null, *) = -1 |
| * StringUtils.ordinalIndexOf("", "", *) = 0 |
| * StringUtils.ordinalIndexOf("aabaabaa", "a", 1) = 0 |
| * StringUtils.ordinalIndexOf("aabaabaa", "a", 2) = 1 |
| * StringUtils.ordinalIndexOf("aabaabaa", "b", 1) = 2 |
| * StringUtils.ordinalIndexOf("aabaabaa", "b", 2) = 5 |
| * StringUtils.ordinalIndexOf("aabaabaa", "ab", 1) = 1 |
| * StringUtils.ordinalIndexOf("aabaabaa", "ab", 2) = 4 |
| * StringUtils.ordinalIndexOf("aabaabaa", "", 1) = 0 |
| * StringUtils.ordinalIndexOf("aabaabaa", "", 2) = 0 |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @param searchStr the String to find, may be null |
| * @param ordinal the n-th <code>searchStr</code> to find |
| * @return the n-th index of the search String, |
| * <code>-1</code> (<code>INDEX_NOT_FOUND</code>) if no match or <code>null</code> string input |
| * @since 2.1 |
| */ |
| public static int ordinalIndexOf(String str, String searchStr, int ordinal) { |
| if (str == null || searchStr == null || ordinal <= 0) { |
| return INDEX_NOT_FOUND; |
| } |
| if (searchStr.length() == 0) { |
| return 0; |
| } |
| int found = 0; |
| int index = INDEX_NOT_FOUND; |
| do { |
| index = str.indexOf(searchStr, index + 1); |
| if (index < 0) { |
| return index; |
| } |
| found++; |
| } while (found < ordinal); |
| return index; |
| } |
| |
| /** |
| * <p>Finds the first index within a String, handling <code>null</code>. |
| * This method uses {@link String#indexOf(String, int)}.</p> |
| * |
| * <p>A <code>null</code> String will return <code>-1</code>. |
| * A negative start position is treated as zero. |
| * An empty ("") search String always matches. |
| * A start position greater than the string length only matches |
| * an empty search String.</p> |
| * |
| * <pre> |
| * StringUtils.indexOf(null, *, *) = -1 |
| * StringUtils.indexOf(*, null, *) = -1 |
| * StringUtils.indexOf("", "", 0) = 0 |
| * StringUtils.indexOf("aabaabaa", "a", 0) = 0 |
| * StringUtils.indexOf("aabaabaa", "b", 0) = 2 |
| * StringUtils.indexOf("aabaabaa", "ab", 0) = 1 |
| * StringUtils.indexOf("aabaabaa", "b", 3) = 5 |
| * StringUtils.indexOf("aabaabaa", "b", 9) = -1 |
| * StringUtils.indexOf("aabaabaa", "b", -1) = 2 |
| * StringUtils.indexOf("aabaabaa", "", 2) = 2 |
| * StringUtils.indexOf("abc", "", 9) = 3 |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @param searchStr the String to find, may be null |
| * @param startPos the start position, negative treated as zero |
| * @return the first index of the search String, |
| * -1 if no match or <code>null</code> string input |
| * @since 2.0 |
| */ |
| public static int indexOf(String str, String searchStr, int startPos) { |
| if (str == null || searchStr == null) { |
| return -1; |
| } |
| // JDK1.2/JDK1.3 have a bug, when startPos > str.length for "", hence |
| if (searchStr.length() == 0 && startPos >= str.length()) { |
| return str.length(); |
| } |
| return str.indexOf(searchStr, startPos); |
| } |
| |
| // LastIndexOf |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Finds the last index within a String, handling <code>null</code>. |
| * This method uses {@link String#lastIndexOf(int)}.</p> |
| * |
| * <p>A <code>null</code> or empty ("") String will return <code>-1</code>.</p> |
| * |
| * <pre> |
| * StringUtils.lastIndexOf(null, *) = -1 |
| * StringUtils.lastIndexOf("", *) = -1 |
| * StringUtils.lastIndexOf("aabaabaa", 'a') = 7 |
| * StringUtils.lastIndexOf("aabaabaa", 'b') = 5 |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @param searchChar the character to find |
| * @return the last index of the search character, |
| * -1 if no match or <code>null</code> string input |
| * @since 2.0 |
| */ |
| public static int lastIndexOf(String str, char searchChar) { |
| if (isEmpty(str)) { |
| return -1; |
| } |
| return str.lastIndexOf(searchChar); |
| } |
| |
| /** |
| * <p>Finds the last index within a String from a start position, |
| * handling <code>null</code>. |
| * This method uses {@link String#lastIndexOf(int, int)}.</p> |
| * |
| * <p>A <code>null</code> or empty ("") String will return <code>-1</code>. |
| * A negative start position returns <code>-1</code>. |
| * A start position greater than the string length searches the whole string.</p> |
| * |
| * <pre> |
| * StringUtils.lastIndexOf(null, *, *) = -1 |
| * StringUtils.lastIndexOf("", *, *) = -1 |
| * StringUtils.lastIndexOf("aabaabaa", 'b', 8) = 5 |
| * StringUtils.lastIndexOf("aabaabaa", 'b', 4) = 2 |
| * StringUtils.lastIndexOf("aabaabaa", 'b', 0) = -1 |
| * StringUtils.lastIndexOf("aabaabaa", 'b', 9) = 5 |
| * StringUtils.lastIndexOf("aabaabaa", 'b', -1) = -1 |
| * StringUtils.lastIndexOf("aabaabaa", 'a', 0) = 0 |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @param searchChar the character to find |
| * @param startPos the start position |
| * @return the last index of the search character, |
| * -1 if no match or <code>null</code> string input |
| * @since 2.0 |
| */ |
| public static int lastIndexOf(String str, char searchChar, int startPos) { |
| if (isEmpty(str)) { |
| return -1; |
| } |
| return str.lastIndexOf(searchChar, startPos); |
| } |
| |
| /** |
| * <p>Finds the last index within a String, handling <code>null</code>. |
| * This method uses {@link String#lastIndexOf(String)}.</p> |
| * |
| * <p>A <code>null</code> String will return <code>-1</code>.</p> |
| * |
| * <pre> |
| * StringUtils.lastIndexOf(null, *) = -1 |
| * StringUtils.lastIndexOf(*, null) = -1 |
| * StringUtils.lastIndexOf("", "") = 0 |
| * StringUtils.lastIndexOf("aabaabaa", "a") = 0 |
| * StringUtils.lastIndexOf("aabaabaa", "b") = 2 |
| * StringUtils.lastIndexOf("aabaabaa", "ab") = 1 |
| * StringUtils.lastIndexOf("aabaabaa", "") = 8 |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @param searchStr the String to find, may be null |
| * @return the last index of the search String, |
| * -1 if no match or <code>null</code> string input |
| * @since 2.0 |
| */ |
| public static int lastIndexOf(String str, String searchStr) { |
| if (str == null || searchStr == null) { |
| return -1; |
| } |
| return str.lastIndexOf(searchStr); |
| } |
| |
| /** |
| * <p>Finds the first index within a String, handling <code>null</code>. |
| * This method uses {@link String#lastIndexOf(String, int)}.</p> |
| * |
| * <p>A <code>null</code> String will return <code>-1</code>. |
| * A negative start position returns <code>-1</code>. |
| * An empty ("") search String always matches unless the start position is negative. |
| * A start position greater than the string length searches the whole string.</p> |
| * |
| * <pre> |
| * StringUtils.lastIndexOf(null, *, *) = -1 |
| * StringUtils.lastIndexOf(*, null, *) = -1 |
| * StringUtils.lastIndexOf("aabaabaa", "a", 8) = 7 |
| * StringUtils.lastIndexOf("aabaabaa", "b", 8) = 5 |
| * StringUtils.lastIndexOf("aabaabaa", "ab", 8) = 4 |
| * StringUtils.lastIndexOf("aabaabaa", "b", 9) = 5 |
| * StringUtils.lastIndexOf("aabaabaa", "b", -1) = -1 |
| * StringUtils.lastIndexOf("aabaabaa", "a", 0) = 0 |
| * StringUtils.lastIndexOf("aabaabaa", "b", 0) = -1 |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @param searchStr the String to find, may be null |
| * @param startPos the start position, negative treated as zero |
| * @return the first index of the search String, |
| * -1 if no match or <code>null</code> string input |
| * @since 2.0 |
| */ |
| public static int lastIndexOf(String str, String searchStr, int startPos) { |
| if (str == null || searchStr == null) { |
| return -1; |
| } |
| return str.lastIndexOf(searchStr, startPos); |
| } |
| |
| // Contains |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Checks if String contains a search character, handling <code>null</code>. |
| * This method uses {@link String#indexOf(int)}.</p> |
| * |
| * <p>A <code>null</code> or empty ("") String will return <code>false</code>.</p> |
| * |
| * <pre> |
| * StringUtils.contains(null, *) = false |
| * StringUtils.contains("", *) = false |
| * StringUtils.contains("abc", 'a') = true |
| * StringUtils.contains("abc", 'z') = false |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @param searchChar the character to find |
| * @return true if the String contains the search character, |
| * false if not or <code>null</code> string input |
| * @since 2.0 |
| */ |
| public static boolean contains(String str, char searchChar) { |
| if (isEmpty(str)) { |
| return false; |
| } |
| return str.indexOf(searchChar) >= 0; |
| } |
| |
| /** |
| * <p>Checks if String contains a search String, handling <code>null</code>. |
| * This method uses {@link String#indexOf(String)}.</p> |
| * |
| * <p>A <code>null</code> String will return <code>false</code>.</p> |
| * |
| * <pre> |
| * StringUtils.contains(null, *) = false |
| * StringUtils.contains(*, null) = false |
| * StringUtils.contains("", "") = true |
| * StringUtils.contains("abc", "") = true |
| * StringUtils.contains("abc", "a") = true |
| * StringUtils.contains("abc", "z") = false |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @param searchStr the String to find, may be null |
| * @return true if the String contains the search String, |
| * false if not or <code>null</code> string input |
| * @since 2.0 |
| */ |
| public static boolean contains(String str, String searchStr) { |
| if (str == null || searchStr == null) { |
| return false; |
| } |
| return str.indexOf(searchStr) >= 0; |
| } |
| |
| /** |
| * <p>Checks if String contains a search String irrespective of case, |
| * handling <code>null</code>. This method uses |
| * {@link #contains(String, String)}.</p> |
| * |
| * <p>A <code>null</code> String will return <code>false</code>.</p> |
| * |
| * <pre> |
| * StringUtils.contains(null, *) = false |
| * StringUtils.contains(*, null) = false |
| * StringUtils.contains("", "") = true |
| * StringUtils.contains("abc", "") = true |
| * StringUtils.contains("abc", "a") = true |
| * StringUtils.contains("abc", "z") = false |
| * StringUtils.contains("abc", "A") = true |
| * StringUtils.contains("abc", "Z") = false |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @param searchStr the String to find, may be null |
| * @return true if the String contains the search String irrespective of |
| * case or false if not or <code>null</code> string input |
| */ |
| public static boolean containsIgnoreCase(String str, String searchStr) { |
| if (str == null || searchStr == null) { |
| return false; |
| } |
| return contains(str.toUpperCase(), searchStr.toUpperCase()); |
| } |
| |
| // IndexOfAny chars |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Search a String to find the first index of any |
| * character in the given set of characters.</p> |
| * |
| * <p>A <code>null</code> String will return <code>-1</code>. |
| * A <code>null</code> or zero length search array will return <code>-1</code>.</p> |
| * |
| * <pre> |
| * StringUtils.indexOfAny(null, *) = -1 |
| * StringUtils.indexOfAny("", *) = -1 |
| * StringUtils.indexOfAny(*, null) = -1 |
| * StringUtils.indexOfAny(*, []) = -1 |
| * StringUtils.indexOfAny("zzabyycdxx",['z','a']) = 0 |
| * StringUtils.indexOfAny("zzabyycdxx",['b','y']) = 3 |
| * StringUtils.indexOfAny("aba", ['z']) = -1 |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @param searchChars the chars to search for, may be null |
| * @return the index of any of the chars, -1 if no match or null input |
| * @since 2.0 |
| */ |
| public static int indexOfAny(String str, char[] searchChars) { |
| if (isEmpty(str) || ArrayUtils.isEmpty(searchChars)) { |
| return -1; |
| } |
| for (int i = 0; i < str.length(); i++) { |
| char ch = str.charAt(i); |
| for (int j = 0; j < searchChars.length; j++) { |
| if (searchChars[j] == ch) { |
| return i; |
| } |
| } |
| } |
| return -1; |
| } |
| |
| /** |
| * <p>Search a String to find the first index of any |
| * character in the given set of characters.</p> |
| * |
| * <p>A <code>null</code> String will return <code>-1</code>. |
| * A <code>null</code> search string will return <code>-1</code>.</p> |
| * |
| * <pre> |
| * StringUtils.indexOfAny(null, *) = -1 |
| * StringUtils.indexOfAny("", *) = -1 |
| * StringUtils.indexOfAny(*, null) = -1 |
| * StringUtils.indexOfAny(*, "") = -1 |
| * StringUtils.indexOfAny("zzabyycdxx", "za") = 0 |
| * StringUtils.indexOfAny("zzabyycdxx", "by") = 3 |
| * StringUtils.indexOfAny("aba","z") = -1 |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @param searchChars the chars to search for, may be null |
| * @return the index of any of the chars, -1 if no match or null input |
| * @since 2.0 |
| */ |
| public static int indexOfAny(String str, String searchChars) { |
| if (isEmpty(str) || isEmpty(searchChars)) { |
| return -1; |
| } |
| return indexOfAny(str, searchChars.toCharArray()); |
| } |
| |
| // IndexOfAnyBut chars |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Search a String to find the first index of any |
| * character not in the given set of characters.</p> |
| * |
| * <p>A <code>null</code> String will return <code>-1</code>. |
| * A <code>null</code> or zero length search array will return <code>-1</code>.</p> |
| * |
| * <pre> |
| * StringUtils.indexOfAnyBut(null, *) = -1 |
| * StringUtils.indexOfAnyBut("", *) = -1 |
| * StringUtils.indexOfAnyBut(*, null) = -1 |
| * StringUtils.indexOfAnyBut(*, []) = -1 |
| * StringUtils.indexOfAnyBut("zzabyycdxx",'za') = 3 |
| * StringUtils.indexOfAnyBut("zzabyycdxx", '') = 0 |
| * StringUtils.indexOfAnyBut("aba", 'ab') = -1 |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @param searchChars the chars to search for, may be null |
| * @return the index of any of the chars, -1 if no match or null input |
| * @since 2.0 |
| */ |
| public static int indexOfAnyBut(String str, char[] searchChars) { |
| if (isEmpty(str) || ArrayUtils.isEmpty(searchChars)) { |
| return -1; |
| } |
| outer : for (int i = 0; i < str.length(); i++) { |
| char ch = str.charAt(i); |
| for (int j = 0; j < searchChars.length; j++) { |
| if (searchChars[j] == ch) { |
| continue outer; |
| } |
| } |
| return i; |
| } |
| return -1; |
| } |
| |
| /** |
| * <p>Search a String to find the first index of any |
| * character not in the given set of characters.</p> |
| * |
| * <p>A <code>null</code> String will return <code>-1</code>. |
| * A <code>null</code> search string will return <code>-1</code>.</p> |
| * |
| * <pre> |
| * StringUtils.indexOfAnyBut(null, *) = -1 |
| * StringUtils.indexOfAnyBut("", *) = -1 |
| * StringUtils.indexOfAnyBut(*, null) = -1 |
| * StringUtils.indexOfAnyBut(*, "") = -1 |
| * StringUtils.indexOfAnyBut("zzabyycdxx", "za") = 3 |
| * StringUtils.indexOfAnyBut("zzabyycdxx", "") = 0 |
| * StringUtils.indexOfAnyBut("aba","ab") = -1 |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @param searchChars the chars to search for, may be null |
| * @return the index of any of the chars, -1 if no match or null input |
| * @since 2.0 |
| */ |
| public static int indexOfAnyBut(String str, String searchChars) { |
| if (isEmpty(str) || isEmpty(searchChars)) { |
| return -1; |
| } |
| for (int i = 0; i < str.length(); i++) { |
| if (searchChars.indexOf(str.charAt(i)) < 0) { |
| return i; |
| } |
| } |
| return -1; |
| } |
| |
| // ContainsOnly |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Checks if the String contains only certain characters.</p> |
| * |
| * <p>A <code>null</code> String will return <code>false</code>. |
| * A <code>null</code> valid character array will return <code>false</code>. |
| * An empty String ("") always returns <code>true</code>.</p> |
| * |
| * <pre> |
| * StringUtils.containsOnly(null, *) = false |
| * StringUtils.containsOnly(*, null) = false |
| * StringUtils.containsOnly("", *) = true |
| * StringUtils.containsOnly("ab", '') = false |
| * StringUtils.containsOnly("abab", 'abc') = true |
| * StringUtils.containsOnly("ab1", 'abc') = false |
| * StringUtils.containsOnly("abz", 'abc') = false |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @param valid an array of valid chars, may be null |
| * @return true if it only contains valid chars and is non-null |
| */ |
| public static boolean containsOnly(String str, char[] valid) { |
| // All these pre-checks are to maintain API with an older version |
| if ((valid == null) || (str == null)) { |
| return false; |
| } |
| if (str.length() == 0) { |
| return true; |
| } |
| if (valid.length == 0) { |
| return false; |
| } |
| return indexOfAnyBut(str, valid) == -1; |
| } |
| |
| /** |
| * <p>Checks if the String contains only certain characters.</p> |
| * |
| * <p>A <code>null</code> String will return <code>false</code>. |
| * A <code>null</code> valid character String will return <code>false</code>. |
| * An empty String ("") always returns <code>true</code>.</p> |
| * |
| * <pre> |
| * StringUtils.containsOnly(null, *) = false |
| * StringUtils.containsOnly(*, null) = false |
| * StringUtils.containsOnly("", *) = true |
| * StringUtils.containsOnly("ab", "") = false |
| * StringUtils.containsOnly("abab", "abc") = true |
| * StringUtils.containsOnly("ab1", "abc") = false |
| * StringUtils.containsOnly("abz", "abc") = false |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @param validChars a String of valid chars, may be null |
| * @return true if it only contains valid chars and is non-null |
| * @since 2.0 |
| */ |
| public static boolean containsOnly(String str, String validChars) { |
| if (str == null || validChars == null) { |
| return false; |
| } |
| return containsOnly(str, validChars.toCharArray()); |
| } |
| |
| // ContainsNone |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Checks that the String does not contain certain characters.</p> |
| * |
| * <p>A <code>null</code> String will return <code>true</code>. |
| * A <code>null</code> invalid character array will return <code>true</code>. |
| * An empty String ("") always returns true.</p> |
| * |
| * <pre> |
| * StringUtils.containsNone(null, *) = true |
| * StringUtils.containsNone(*, null) = true |
| * StringUtils.containsNone("", *) = true |
| * StringUtils.containsNone("ab", '') = true |
| * StringUtils.containsNone("abab", 'xyz') = true |
| * StringUtils.containsNone("ab1", 'xyz') = true |
| * StringUtils.containsNone("abz", 'xyz') = false |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @param invalidChars an array of invalid chars, may be null |
| * @return true if it contains none of the invalid chars, or is null |
| * @since 2.0 |
| */ |
| public static boolean containsNone(String str, char[] invalidChars) { |
| if (str == null || invalidChars == null) { |
| return true; |
| } |
| int strSize = str.length(); |
| int validSize = invalidChars.length; |
| for (int i = 0; i < strSize; i++) { |
| char ch = str.charAt(i); |
| for (int j = 0; j < validSize; j++) { |
| if (invalidChars[j] == ch) { |
| return false; |
| } |
| } |
| } |
| return true; |
| } |
| |
| /** |
| * <p>Checks that the String does not contain certain characters.</p> |
| * |
| * <p>A <code>null</code> String will return <code>true</code>. |
| * A <code>null</code> invalid character array will return <code>true</code>. |
| * An empty String ("") always returns true.</p> |
| * |
| * <pre> |
| * StringUtils.containsNone(null, *) = true |
| * StringUtils.containsNone(*, null) = true |
| * StringUtils.containsNone("", *) = true |
| * StringUtils.containsNone("ab", "") = true |
| * StringUtils.containsNone("abab", "xyz") = true |
| * StringUtils.containsNone("ab1", "xyz") = true |
| * StringUtils.containsNone("abz", "xyz") = false |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @param invalidChars a String of invalid chars, may be null |
| * @return true if it contains none of the invalid chars, or is null |
| * @since 2.0 |
| */ |
| public static boolean containsNone(String str, String invalidChars) { |
| if (str == null || invalidChars == null) { |
| return true; |
| } |
| return containsNone(str, invalidChars.toCharArray()); |
| } |
| |
| // IndexOfAny strings |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Find the first index of any of a set of potential substrings.</p> |
| * |
| * <p>A <code>null</code> String will return <code>-1</code>. |
| * A <code>null</code> or zero length search array will return <code>-1</code>. |
| * A <code>null</code> search array entry will be ignored, but a search |
| * array containing "" will return <code>0</code> if <code>str</code> is not |
| * null. This method uses {@link String#indexOf(String)}.</p> |
| * |
| * <pre> |
| * StringUtils.indexOfAny(null, *) = -1 |
| * StringUtils.indexOfAny(*, null) = -1 |
| * StringUtils.indexOfAny(*, []) = -1 |
| * StringUtils.indexOfAny("zzabyycdxx", ["ab","cd"]) = 2 |
| * StringUtils.indexOfAny("zzabyycdxx", ["cd","ab"]) = 2 |
| * StringUtils.indexOfAny("zzabyycdxx", ["mn","op"]) = -1 |
| * StringUtils.indexOfAny("zzabyycdxx", ["zab","aby"]) = 1 |
| * StringUtils.indexOfAny("zzabyycdxx", [""]) = 0 |
| * StringUtils.indexOfAny("", [""]) = 0 |
| * StringUtils.indexOfAny("", ["a"]) = -1 |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @param searchStrs the Strings to search for, may be null |
| * @return the first index of any of the searchStrs in str, -1 if no match |
| */ |
| public static int indexOfAny(String str, String[] searchStrs) { |
| if ((str == null) || (searchStrs == null)) { |
| return -1; |
| } |
| int sz = searchStrs.length; |
| |
| // String's can't have a MAX_VALUEth index. |
| int ret = Integer.MAX_VALUE; |
| |
| int tmp = 0; |
| for (int i = 0; i < sz; i++) { |
| String search = searchStrs[i]; |
| if (search == null) { |
| continue; |
| } |
| tmp = str.indexOf(search); |
| if (tmp == -1) { |
| continue; |
| } |
| |
| if (tmp < ret) { |
| ret = tmp; |
| } |
| } |
| |
| return (ret == Integer.MAX_VALUE) ? -1 : ret; |
| } |
| |
| /** |
| * <p>Find the latest index of any of a set of potential substrings.</p> |
| * |
| * <p>A <code>null</code> String will return <code>-1</code>. |
| * A <code>null</code> search array will return <code>-1</code>. |
| * A <code>null</code> or zero length search array entry will be ignored, |
| * but a search array containing "" will return the length of <code>str</code> |
| * if <code>str</code> is not null. This method uses {@link String#indexOf(String)}</p> |
| * |
| * <pre> |
| * StringUtils.lastIndexOfAny(null, *) = -1 |
| * StringUtils.lastIndexOfAny(*, null) = -1 |
| * StringUtils.lastIndexOfAny(*, []) = -1 |
| * StringUtils.lastIndexOfAny(*, [null]) = -1 |
| * StringUtils.lastIndexOfAny("zzabyycdxx", ["ab","cd"]) = 6 |
| * StringUtils.lastIndexOfAny("zzabyycdxx", ["cd","ab"]) = 6 |
| * StringUtils.lastIndexOfAny("zzabyycdxx", ["mn","op"]) = -1 |
| * StringUtils.lastIndexOfAny("zzabyycdxx", ["mn","op"]) = -1 |
| * StringUtils.lastIndexOfAny("zzabyycdxx", ["mn",""]) = 10 |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @param searchStrs the Strings to search for, may be null |
| * @return the last index of any of the Strings, -1 if no match |
| */ |
| public static int lastIndexOfAny(String str, String[] searchStrs) { |
| if ((str == null) || (searchStrs == null)) { |
| return -1; |
| } |
| int sz = searchStrs.length; |
| int ret = -1; |
| int tmp = 0; |
| for (int i = 0; i < sz; i++) { |
| String search = searchStrs[i]; |
| if (search == null) { |
| continue; |
| } |
| tmp = str.lastIndexOf(search); |
| if (tmp > ret) { |
| ret = tmp; |
| } |
| } |
| return ret; |
| } |
| |
| // Substring |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Gets a substring from the specified String avoiding exceptions.</p> |
| * |
| * <p>A negative start position can be used to start <code>n</code> |
| * characters from the end of the String.</p> |
| * |
| * <p>A <code>null</code> String will return <code>null</code>. |
| * An empty ("") String will return "".</p> |
| * |
| * <pre> |
| * StringUtils.substring(null, *) = null |
| * StringUtils.substring("", *) = "" |
| * StringUtils.substring("abc", 0) = "abc" |
| * StringUtils.substring("abc", 2) = "c" |
| * StringUtils.substring("abc", 4) = "" |
| * StringUtils.substring("abc", -2) = "bc" |
| * StringUtils.substring("abc", -4) = "abc" |
| * </pre> |
| * |
| * @param str the String to get the substring from, may be null |
| * @param start the position to start from, negative means |
| * count back from the end of the String by this many characters |
| * @return substring from start position, <code>null</code> if null String input |
| */ |
| public static String substring(String str, int start) { |
| if (str == null) { |
| return null; |
| } |
| |
| // handle negatives, which means last n characters |
| if (start < 0) { |
| start = str.length() + start; // remember start is negative |
| } |
| |
| if (start < 0) { |
| start = 0; |
| } |
| if (start > str.length()) { |
| return EMPTY; |
| } |
| |
| return str.substring(start); |
| } |
| |
| /** |
| * <p>Gets a substring from the specified String avoiding exceptions.</p> |
| * |
| * <p>A negative start position can be used to start/end <code>n</code> |
| * characters from the end of the String.</p> |
| * |
| * <p>The returned substring starts with the character in the <code>start</code> |
| * position and ends before the <code>end</code> position. All position counting is |
| * zero-based -- i.e., to start at the beginning of the string use |
| * <code>start = 0</code>. Negative start and end positions can be used to |
| * specify offsets relative to the end of the String.</p> |
| * |
| * <p>If <code>start</code> is not strictly to the left of <code>end</code>, "" |
| * is returned.</p> |
| * |
| * <pre> |
| * StringUtils.substring(null, *, *) = null |
| * StringUtils.substring("", * , *) = ""; |
| * StringUtils.substring("abc", 0, 2) = "ab" |
| * StringUtils.substring("abc", 2, 0) = "" |
| * StringUtils.substring("abc", 2, 4) = "c" |
| * StringUtils.substring("abc", 4, 6) = "" |
| * StringUtils.substring("abc", 2, 2) = "" |
| * StringUtils.substring("abc", -2, -1) = "b" |
| * StringUtils.substring("abc", -4, 2) = "ab" |
| * </pre> |
| * |
| * @param str the String to get the substring from, may be null |
| * @param start the position to start from, negative means |
| * count back from the end of the String by this many characters |
| * @param end the position to end at (exclusive), negative means |
| * count back from the end of the String by this many characters |
| * @return substring from start position to end positon, |
| * <code>null</code> if null String input |
| */ |
| public static String substring(String str, int start, int end) { |
| if (str == null) { |
| return null; |
| } |
| |
| // handle negatives |
| if (end < 0) { |
| end = str.length() + end; // remember end is negative |
| } |
| if (start < 0) { |
| start = str.length() + start; // remember start is negative |
| } |
| |
| // check length next |
| if (end > str.length()) { |
| end = str.length(); |
| } |
| |
| // if start is greater than end, return "" |
| if (start > end) { |
| return EMPTY; |
| } |
| |
| if (start < 0) { |
| start = 0; |
| } |
| if (end < 0) { |
| end = 0; |
| } |
| |
| return str.substring(start, end); |
| } |
| |
| // Left/Right/Mid |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Gets the leftmost <code>len</code> characters of a String.</p> |
| * |
| * <p>If <code>len</code> characters are not available, or the |
| * String is <code>null</code>, the String will be returned without |
| * an exception. An exception is thrown if len is negative.</p> |
| * |
| * <pre> |
| * StringUtils.left(null, *) = null |
| * StringUtils.left(*, -ve) = "" |
| * StringUtils.left("", *) = "" |
| * StringUtils.left("abc", 0) = "" |
| * StringUtils.left("abc", 2) = "ab" |
| * StringUtils.left("abc", 4) = "abc" |
| * </pre> |
| * |
| * @param str the String to get the leftmost characters from, may be null |
| * @param len the length of the required String, must be zero or positive |
| * @return the leftmost characters, <code>null</code> if null String input |
| */ |
| public static String left(String str, int len) { |
| if (str == null) { |
| return null; |
| } |
| if (len < 0) { |
| return EMPTY; |
| } |
| if (str.length() <= len) { |
| return str; |
| } else { |
| return str.substring(0, len); |
| } |
| } |
| |
| /** |
| * <p>Gets the rightmost <code>len</code> characters of a String.</p> |
| * |
| * <p>If <code>len</code> characters are not available, or the String |
| * is <code>null</code>, the String will be returned without an |
| * an exception. An exception is thrown if len is negative.</p> |
| * |
| * <pre> |
| * StringUtils.right(null, *) = null |
| * StringUtils.right(*, -ve) = "" |
| * StringUtils.right("", *) = "" |
| * StringUtils.right("abc", 0) = "" |
| * StringUtils.right("abc", 2) = "bc" |
| * StringUtils.right("abc", 4) = "abc" |
| * </pre> |
| * |
| * @param str the String to get the rightmost characters from, may be null |
| * @param len the length of the required String, must be zero or positive |
| * @return the rightmost characters, <code>null</code> if null String input |
| */ |
| public static String right(String str, int len) { |
| if (str == null) { |
| return null; |
| } |
| if (len < 0) { |
| return EMPTY; |
| } |
| if (str.length() <= len) { |
| return str; |
| } else { |
| return str.substring(str.length() - len); |
| } |
| } |
| |
| /** |
| * <p>Gets <code>len</code> characters from the middle of a String.</p> |
| * |
| * <p>If <code>len</code> characters are not available, the remainder |
| * of the String will be returned without an exception. If the |
| * String is <code>null</code>, <code>null</code> will be returned. |
| * An exception is thrown if len is negative.</p> |
| * |
| * <pre> |
| * StringUtils.mid(null, *, *) = null |
| * StringUtils.mid(*, *, -ve) = "" |
| * StringUtils.mid("", 0, *) = "" |
| * StringUtils.mid("abc", 0, 2) = "ab" |
| * StringUtils.mid("abc", 0, 4) = "abc" |
| * StringUtils.mid("abc", 2, 4) = "c" |
| * StringUtils.mid("abc", 4, 2) = "" |
| * StringUtils.mid("abc", -2, 2) = "ab" |
| * </pre> |
| * |
| * @param str the String to get the characters from, may be null |
| * @param pos the position to start from, negative treated as zero |
| * @param len the length of the required String, must be zero or positive |
| * @return the middle characters, <code>null</code> if null String input |
| */ |
| public static String mid(String str, int pos, int len) { |
| if (str == null) { |
| return null; |
| } |
| if (len < 0 || pos > str.length()) { |
| return EMPTY; |
| } |
| if (pos < 0) { |
| pos = 0; |
| } |
| if (str.length() <= (pos + len)) { |
| return str.substring(pos); |
| } else { |
| return str.substring(pos, pos + len); |
| } |
| } |
| |
| // SubStringAfter/SubStringBefore |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Gets the substring before the first occurrence of a separator. |
| * The separator is not returned.</p> |
| * |
| * <p>A <code>null</code> string input will return <code>null</code>. |
| * An empty ("") string input will return the empty string. |
| * A <code>null</code> separator will return the input string.</p> |
| * |
| * <pre> |
| * StringUtils.substringBefore(null, *) = null |
| * StringUtils.substringBefore("", *) = "" |
| * StringUtils.substringBefore("abc", "a") = "" |
| * StringUtils.substringBefore("abcba", "b") = "a" |
| * StringUtils.substringBefore("abc", "c") = "ab" |
| * StringUtils.substringBefore("abc", "d") = "abc" |
| * StringUtils.substringBefore("abc", "") = "" |
| * StringUtils.substringBefore("abc", null) = "abc" |
| * </pre> |
| * |
| * @param str the String to get a substring from, may be null |
| * @param separator the String to search for, may be null |
| * @return the substring before the first occurrence of the separator, |
| * <code>null</code> if null String input |
| * @since 2.0 |
| */ |
| public static String substringBefore(String str, String separator) { |
| if (isEmpty(str) || separator == null) { |
| return str; |
| } |
| if (separator.length() == 0) { |
| return EMPTY; |
| } |
| int pos = str.indexOf(separator); |
| if (pos == -1) { |
| return str; |
| } |
| return str.substring(0, pos); |
| } |
| |
| /** |
| * <p>Gets the substring after the first occurrence of a separator. |
| * The separator is not returned.</p> |
| * |
| * <p>A <code>null</code> string input will return <code>null</code>. |
| * An empty ("") string input will return the empty string. |
| * A <code>null</code> separator will return the empty string if the |
| * input string is not <code>null</code>.</p> |
| * |
| * <pre> |
| * StringUtils.substringAfter(null, *) = null |
| * StringUtils.substringAfter("", *) = "" |
| * StringUtils.substringAfter(*, null) = "" |
| * StringUtils.substringAfter("abc", "a") = "bc" |
| * StringUtils.substringAfter("abcba", "b") = "cba" |
| * StringUtils.substringAfter("abc", "c") = "" |
| * StringUtils.substringAfter("abc", "d") = "" |
| * StringUtils.substringAfter("abc", "") = "abc" |
| * </pre> |
| * |
| * @param str the String to get a substring from, may be null |
| * @param separator the String to search for, may be null |
| * @return the substring after the first occurrence of the separator, |
| * <code>null</code> if null String input |
| * @since 2.0 |
| */ |
| public static String substringAfter(String str, String separator) { |
| if (isEmpty(str)) { |
| return str; |
| } |
| if (separator == null) { |
| return EMPTY; |
| } |
| int pos = str.indexOf(separator); |
| if (pos == -1) { |
| return EMPTY; |
| } |
| return str.substring(pos + separator.length()); |
| } |
| |
| /** |
| * <p>Gets the substring before the last occurrence of a separator. |
| * The separator is not returned.</p> |
| * |
| * <p>A <code>null</code> string input will return <code>null</code>. |
| * An empty ("") string input will return the empty string. |
| * An empty or <code>null</code> separator will return the input string.</p> |
| * |
| * <pre> |
| * StringUtils.substringBeforeLast(null, *) = null |
| * StringUtils.substringBeforeLast("", *) = "" |
| * StringUtils.substringBeforeLast("abcba", "b") = "abc" |
| * StringUtils.substringBeforeLast("abc", "c") = "ab" |
| * StringUtils.substringBeforeLast("a", "a") = "" |
| * StringUtils.substringBeforeLast("a", "z") = "a" |
| * StringUtils.substringBeforeLast("a", null) = "a" |
| * StringUtils.substringBeforeLast("a", "") = "a" |
| * </pre> |
| * |
| * @param str the String to get a substring from, may be null |
| * @param separator the String to search for, may be null |
| * @return the substring before the last occurrence of the separator, |
| * <code>null</code> if null String input |
| * @since 2.0 |
| */ |
| public static String substringBeforeLast(String str, String separator) { |
| if (isEmpty(str) || isEmpty(separator)) { |
| return str; |
| } |
| int pos = str.lastIndexOf(separator); |
| if (pos == -1) { |
| return str; |
| } |
| return str.substring(0, pos); |
| } |
| |
| /** |
| * <p>Gets the substring after the last occurrence of a separator. |
| * The separator is not returned.</p> |
| * |
| * <p>A <code>null</code> string input will return <code>null</code>. |
| * An empty ("") string input will return the empty string. |
| * An empty or <code>null</code> separator will return the empty string if |
| * the input string is not <code>null</code>.</p> |
| * |
| * <pre> |
| * StringUtils.substringAfterLast(null, *) = null |
| * StringUtils.substringAfterLast("", *) = "" |
| * StringUtils.substringAfterLast(*, "") = "" |
| * StringUtils.substringAfterLast(*, null) = "" |
| * StringUtils.substringAfterLast("abc", "a") = "bc" |
| * StringUtils.substringAfterLast("abcba", "b") = "a" |
| * StringUtils.substringAfterLast("abc", "c") = "" |
| * StringUtils.substringAfterLast("a", "a") = "" |
| * StringUtils.substringAfterLast("a", "z") = "" |
| * </pre> |
| * |
| * @param str the String to get a substring from, may be null |
| * @param separator the String to search for, may be null |
| * @return the substring after the last occurrence of the separator, |
| * <code>null</code> if null String input |
| * @since 2.0 |
| */ |
| public static String substringAfterLast(String str, String separator) { |
| if (isEmpty(str)) { |
| return str; |
| } |
| if (isEmpty(separator)) { |
| return EMPTY; |
| } |
| int pos = str.lastIndexOf(separator); |
| if (pos == -1 || pos == (str.length() - separator.length())) { |
| return EMPTY; |
| } |
| return str.substring(pos + separator.length()); |
| } |
| |
| // Substring between |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Gets the String that is nested in between two instances of the |
| * same String.</p> |
| * |
| * <p>A <code>null</code> input String returns <code>null</code>. |
| * A <code>null</code> tag returns <code>null</code>.</p> |
| * |
| * <pre> |
| * StringUtils.substringBetween(null, *) = null |
| * StringUtils.substringBetween("", "") = "" |
| * StringUtils.substringBetween("", "tag") = null |
| * StringUtils.substringBetween("tagabctag", null) = null |
| * StringUtils.substringBetween("tagabctag", "") = "" |
| * StringUtils.substringBetween("tagabctag", "tag") = "abc" |
| * </pre> |
| * |
| * @param str the String containing the substring, may be null |
| * @param tag the String before and after the substring, may be null |
| * @return the substring, <code>null</code> if no match |
| * @since 2.0 |
| */ |
| public static String substringBetween(String str, String tag) { |
| return substringBetween(str, tag, tag); |
| } |
| |
| /** |
| * <p>Gets the String that is nested in between two Strings. |
| * Only the first match is returned.</p> |
| * |
| * <p>A <code>null</code> input String returns <code>null</code>. |
| * A <code>null</code> open/close returns <code>null</code> (no match). |
| * An empty ("") open and close returns an empty string.</p> |
| * |
| * <pre> |
| * StringUtils.substringBetween("wx[b]yz", "[", "]") = "b" |
| * StringUtils.substringBetween(null, *, *) = null |
| * StringUtils.substringBetween(*, null, *) = null |
| * StringUtils.substringBetween(*, *, null) = null |
| * StringUtils.substringBetween("", "", "") = "" |
| * StringUtils.substringBetween("", "", "]") = null |
| * StringUtils.substringBetween("", "[", "]") = null |
| * StringUtils.substringBetween("yabcz", "", "") = "" |
| * StringUtils.substringBetween("yabcz", "y", "z") = "abc" |
| * StringUtils.substringBetween("yabczyabcz", "y", "z") = "abc" |
| * </pre> |
| * |
| * @param str the String containing the substring, may be null |
| * @param open the String before the substring, may be null |
| * @param close the String after the substring, may be null |
| * @return the substring, <code>null</code> if no match |
| * @since 2.0 |
| */ |
| public static String substringBetween(String str, String open, String close) { |
| if (str == null || open == null || close == null) { |
| return null; |
| } |
| int start = str.indexOf(open); |
| if (start != -1) { |
| int end = str.indexOf(close, start + open.length()); |
| if (end != -1) { |
| return str.substring(start + open.length(), end); |
| } |
| } |
| return null; |
| } |
| |
| /** |
| * <p>Searches a String for substrings delimited by a start and end tag, |
| * returning all matching substrings in an array.</p> |
| * |
| * <p>A <code>null</code> input String returns <code>null</code>. |
| * A <code>null</code> open/close returns <code>null</code> (no match). |
| * An empty ("") open/close returns <code>null</code> (no match).</p> |
| * |
| * <pre> |
| * StringUtils.substringsBetween("[a][b][c]", "[", "]") = ["a","b","c"] |
| * StringUtils.substringsBetween(null, *, *) = null |
| * StringUtils.substringsBetween(*, null, *) = null |
| * StringUtils.substringsBetween(*, *, null) = null |
| * StringUtils.substringsBetween("", "[", "]") = [] |
| * </pre> |
| * |
| * @param str the String containing the substrings, null returns null, empty returns empty |
| * @param open the String identifying the start of the substring, empty returns null |
| * @param close the String identifying the end of the substring, empty returns null |
| * @return a String Array of substrings, or <code>null</code> if no match |
| * @since 2.3 |
| */ |
| public static String[] substringsBetween(String str, String open, String close) { |
| if (str == null || isEmpty(open) || isEmpty(close)) { |
| return null; |
| } |
| int strLen = str.length(); |
| if (strLen == 0) { |
| return ArrayUtils.EMPTY_STRING_ARRAY; |
| } |
| int closeLen = close.length(); |
| int openLen = open.length(); |
| List list = new ArrayList(); |
| int pos = 0; |
| while (pos < (strLen - closeLen)) { |
| int start = str.indexOf(open, pos); |
| if (start < 0) { |
| break; |
| } |
| start += openLen; |
| int end = str.indexOf(close, start); |
| if (end < 0) { |
| break; |
| } |
| list.add(str.substring(start, end)); |
| pos = end + closeLen; |
| } |
| if (list.size() > 0) { |
| return (String[]) list.toArray(new String [list.size()]); |
| } else { |
| return null; |
| } |
| } |
| |
| // Nested extraction |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Gets the String that is nested in between two instances of the |
| * same String.</p> |
| * |
| * <p>A <code>null</code> input String returns <code>null</code>. |
| * A <code>null</code> tag returns <code>null</code>.</p> |
| * |
| * <pre> |
| * StringUtils.getNestedString(null, *) = null |
| * StringUtils.getNestedString("", "") = "" |
| * StringUtils.getNestedString("", "tag") = null |
| * StringUtils.getNestedString("tagabctag", null) = null |
| * StringUtils.getNestedString("tagabctag", "") = "" |
| * StringUtils.getNestedString("tagabctag", "tag") = "abc" |
| * </pre> |
| * |
| * @param str the String containing nested-string, may be null |
| * @param tag the String before and after nested-string, may be null |
| * @return the nested String, <code>null</code> if no match |
| * @deprecated Use the better named {@link #substringBetween(String, String)}. |
| * Method will be removed in Commons Lang 3.0. |
| */ |
| public static String getNestedString(String str, String tag) { |
| return substringBetween(str, tag, tag); |
| } |
| |
| /** |
| * <p>Gets the String that is nested in between two Strings. |
| * Only the first match is returned.</p> |
| * |
| * <p>A <code>null</code> input String returns <code>null</code>. |
| * A <code>null</code> open/close returns <code>null</code> (no match). |
| * An empty ("") open/close returns an empty string.</p> |
| * |
| * <pre> |
| * StringUtils.getNestedString(null, *, *) = null |
| * StringUtils.getNestedString("", "", "") = "" |
| * StringUtils.getNestedString("", "", "tag") = null |
| * StringUtils.getNestedString("", "tag", "tag") = null |
| * StringUtils.getNestedString("yabcz", null, null) = null |
| * StringUtils.getNestedString("yabcz", "", "") = "" |
| * StringUtils.getNestedString("yabcz", "y", "z") = "abc" |
| * StringUtils.getNestedString("yabczyabcz", "y", "z") = "abc" |
| * </pre> |
| * |
| * @param str the String containing nested-string, may be null |
| * @param open the String before nested-string, may be null |
| * @param close the String after nested-string, may be null |
| * @return the nested String, <code>null</code> if no match |
| * @deprecated Use the better named {@link #substringBetween(String, String, String)}. |
| * Method will be removed in Commons Lang 3.0. |
| */ |
| public static String getNestedString(String str, String open, String close) { |
| return substringBetween(str, open, close); |
| } |
| |
| // Splitting |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Splits the provided text into an array, using whitespace as the |
| * separator. |
| * Whitespace is defined by {@link Character#isWhitespace(char)}.</p> |
| * |
| * <p>The separator is not included in the returned String array. |
| * Adjacent separators are treated as one separator. |
| * For more control over the split use the StrTokenizer class.</p> |
| * |
| * <p>A <code>null</code> input String returns <code>null</code>.</p> |
| * |
| * <pre> |
| * StringUtils.split(null) = null |
| * StringUtils.split("") = [] |
| * StringUtils.split("abc def") = ["abc", "def"] |
| * StringUtils.split("abc def") = ["abc", "def"] |
| * StringUtils.split(" abc ") = ["abc"] |
| * </pre> |
| * |
| * @param str the String to parse, may be null |
| * @return an array of parsed Strings, <code>null</code> if null String input |
| */ |
| public static String[] split(String str) { |
| return split(str, null, -1); |
| } |
| |
| /** |
| * <p>Splits the provided text into an array, separator specified. |
| * This is an alternative to using StringTokenizer.</p> |
| * |
| * <p>The separator is not included in the returned String array. |
| * Adjacent separators are treated as one separator. |
| * For more control over the split use the StrTokenizer class.</p> |
| * |
| * <p>A <code>null</code> input String returns <code>null</code>.</p> |
| * |
| * <pre> |
| * StringUtils.split(null, *) = null |
| * StringUtils.split("", *) = [] |
| * StringUtils.split("a.b.c", '.') = ["a", "b", "c"] |
| * StringUtils.split("a..b.c", '.') = ["a", "b", "c"] |
| * StringUtils.split("a:b:c", '.') = ["a:b:c"] |
| * StringUtils.split("a\tb\nc", null) = ["a", "b", "c"] |
| * StringUtils.split("a b c", ' ') = ["a", "b", "c"] |
| * </pre> |
| * |
| * @param str the String to parse, may be null |
| * @param separatorChar the character used as the delimiter, |
| * <code>null</code> splits on whitespace |
| * @return an array of parsed Strings, <code>null</code> if null String input |
| * @since 2.0 |
| */ |
| public static String[] split(String str, char separatorChar) { |
| return splitWorker(str, separatorChar, false); |
| } |
| |
| /** |
| * <p>Splits the provided text into an array, separators specified. |
| * This is an alternative to using StringTokenizer.</p> |
| * |
| * <p>The separator is not included in the returned String array. |
| * Adjacent separators are treated as one separator. |
| * For more control over the split use the StrTokenizer class.</p> |
| * |
| * <p>A <code>null</code> input String returns <code>null</code>. |
| * A <code>null</code> separatorChars splits on whitespace.</p> |
| * |
| * <pre> |
| * StringUtils.split(null, *) = null |
| * StringUtils.split("", *) = [] |
| * StringUtils.split("abc def", null) = ["abc", "def"] |
| * StringUtils.split("abc def", " ") = ["abc", "def"] |
| * StringUtils.split("abc def", " ") = ["abc", "def"] |
| * StringUtils.split("ab:cd:ef", ":") = ["ab", "cd", "ef"] |
| * </pre> |
| * |
| * @param str the String to parse, may be null |
| * @param separatorChars the characters used as the delimiters, |
| * <code>null</code> splits on whitespace |
| * @return an array of parsed Strings, <code>null</code> if null String input |
| */ |
| public static String[] split(String str, String separatorChars) { |
| return splitWorker(str, separatorChars, -1, false); |
| } |
| |
| /** |
| * <p>Splits the provided text into an array with a maximum length, |
| * separators specified.</p> |
| * |
| * <p>The separator is not included in the returned String array. |
| * Adjacent separators are treated as one separator.</p> |
| * |
| * <p>A <code>null</code> input String returns <code>null</code>. |
| * A <code>null</code> separatorChars splits on whitespace.</p> |
| * |
| * <p>If more than <code>max</code> delimited substrings are found, the last |
| * returned string includes all characters after the first <code>max - 1</code> |
| * returned strings (including separator characters).</p> |
| * |
| * <pre> |
| * StringUtils.split(null, *, *) = null |
| * StringUtils.split("", *, *) = [] |
| * StringUtils.split("ab de fg", null, 0) = ["ab", "cd", "ef"] |
| * StringUtils.split("ab de fg", null, 0) = ["ab", "cd", "ef"] |
| * StringUtils.split("ab:cd:ef", ":", 0) = ["ab", "cd", "ef"] |
| * StringUtils.split("ab:cd:ef", ":", 2) = ["ab", "cd:ef"] |
| * </pre> |
| * |
| * @param str the String to parse, may be null |
| * @param separatorChars the characters used as the delimiters, |
| * <code>null</code> splits on whitespace |
| * @param max the maximum number of elements to include in the |
| * array. A zero or negative value implies no limit |
| * @return an array of parsed Strings, <code>null</code> if null String input |
| */ |
| public static String[] split(String str, String separatorChars, int max) { |
| return splitWorker(str, separatorChars, max, false); |
| } |
| |
| /** |
| * <p>Splits the provided text into an array, separator string specified.</p> |
| * |
| * <p>The separator(s) will not be included in the returned String array. |
| * Adjacent separators are treated as one separator.</p> |
| * |
| * <p>A <code>null</code> input String returns <code>null</code>. |
| * A <code>null</code> separator splits on whitespace.</p> |
| * |
| * <pre> |
| * StringUtils.splitByWholeSeparator(null, *) = null |
| * StringUtils.splitByWholeSeparator("", *) = [] |
| * StringUtils.splitByWholeSeparator("ab de fg", null) = ["ab", "de", "fg"] |
| * StringUtils.splitByWholeSeparator("ab de fg", null) = ["ab", "de", "fg"] |
| * StringUtils.splitByWholeSeparator("ab:cd:ef", ":") = ["ab", "cd", "ef"] |
| * StringUtils.splitByWholeSeparator("ab-!-cd-!-ef", "-!-") = ["ab", "cd", "ef"] |
| * </pre> |
| * |
| * @param str the String to parse, may be null |
| * @param separator String containing the String to be used as a delimiter, |
| * <code>null</code> splits on whitespace |
| * @return an array of parsed Strings, <code>null</code> if null String was input |
| */ |
| public static String[] splitByWholeSeparator(String str, String separator) { |
| return splitByWholeSeparator( str, separator, -1 ) ; |
| } |
| |
| /** |
| * <p>Splits the provided text into an array, separator string specified. |
| * Returns a maximum of <code>max</code> substrings.</p> |
| * |
| * <p>The separator(s) will not be included in the returned String array. |
| * Adjacent separators are treated as one separator.</p> |
| * |
| * <p>A <code>null</code> input String returns <code>null</code>. |
| * A <code>null</code> separator splits on whitespace.</p> |
| * |
| * <pre> |
| * StringUtils.splitByWholeSeparator(null, *, *) = null |
| * StringUtils.splitByWholeSeparator("", *, *) = [] |
| * StringUtils.splitByWholeSeparator("ab de fg", null, 0) = ["ab", "de", "fg"] |
| * StringUtils.splitByWholeSeparator("ab de fg", null, 0) = ["ab", "de", "fg"] |
| * StringUtils.splitByWholeSeparator("ab:cd:ef", ":", 2) = ["ab", "cd:ef"] |
| * StringUtils.splitByWholeSeparator("ab-!-cd-!-ef", "-!-", 5) = ["ab", "cd", "ef"] |
| * StringUtils.splitByWholeSeparator("ab-!-cd-!-ef", "-!-", 2) = ["ab", "cd-!-ef"] |
| * </pre> |
| * |
| * @param str the String to parse, may be null |
| * @param separator String containing the String to be used as a delimiter, |
| * <code>null</code> splits on whitespace |
| * @param max the maximum number of elements to include in the returned |
| * array. A zero or negative value implies no limit. |
| * @return an array of parsed Strings, <code>null</code> if null String was input |
| */ |
| public static String[] splitByWholeSeparator( String str, String separator, int max ) { |
| if (str == null) { |
| return null; |
| } |
| |
| int len = str.length() ; |
| |
| if (len == 0) { |
| return ArrayUtils.EMPTY_STRING_ARRAY; |
| } |
| |
| if ( ( separator == null ) || ( "".equals( separator ) ) ) { |
| // Split on whitespace. |
| return split( str, null, max ) ; |
| } |
| |
| |
| int separatorLength = separator.length() ; |
| |
| ArrayList substrings = new ArrayList() ; |
| int numberOfSubstrings = 0 ; |
| int beg = 0 ; |
| int end = 0 ; |
| while ( end < len ) { |
| end = str.indexOf( separator, beg ) ; |
| |
| if ( end > -1 ) { |
| if ( end > beg ) { |
| numberOfSubstrings += 1 ; |
| |
| if ( numberOfSubstrings == max ) { |
| end = len ; |
| substrings.add( str.substring( beg ) ) ; |
| } else { |
| // The following is OK, because String.substring( beg, end ) excludes |
| // the character at the position 'end'. |
| substrings.add( str.substring( beg, end ) ) ; |
| |
| // Set the starting point for the next search. |
| // The following is equivalent to beg = end + (separatorLength - 1) + 1, |
| // which is the right calculation: |
| beg = end + separatorLength ; |
| } |
| } else { |
| // We found a consecutive occurrence of the separator, so skip it. |
| beg = end + separatorLength ; |
| } |
| } else { |
| // String.substring( beg ) goes from 'beg' to the end of the String. |
| substrings.add( str.substring( beg ) ) ; |
| end = len ; |
| } |
| } |
| |
| return (String[]) substrings.toArray( new String[substrings.size()] ) ; |
| } |
| |
| |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Splits the provided text into an array, using whitespace as the |
| * separator, preserving all tokens, including empty tokens created by |
| * adjacent separators. This is an alternative to using StringTokenizer. |
| * Whitespace is defined by {@link Character#isWhitespace(char)}.</p> |
| * |
| * <p>The separator is not included in the returned String array. |
| * Adjacent separators are treated as separators for empty tokens. |
| * For more control over the split use the StrTokenizer class.</p> |
| * |
| * <p>A <code>null</code> input String returns <code>null</code>.</p> |
| * |
| * <pre> |
| * StringUtils.splitPreserveAllTokens(null) = null |
| * StringUtils.splitPreserveAllTokens("") = [] |
| * StringUtils.splitPreserveAllTokens("abc def") = ["abc", "def"] |
| * StringUtils.splitPreserveAllTokens("abc def") = ["abc", "", "def"] |
| * StringUtils.splitPreserveAllTokens(" abc ") = ["", "abc", ""] |
| * </pre> |
| * |
| * @param str the String to parse, may be <code>null</code> |
| * @return an array of parsed Strings, <code>null</code> if null String input |
| * @since 2.1 |
| */ |
| public static String[] splitPreserveAllTokens(String str) { |
| return splitWorker(str, null, -1, true); |
| } |
| |
| /** |
| * <p>Splits the provided text into an array, separator specified, |
| * preserving all tokens, including empty tokens created by adjacent |
| * separators. This is an alternative to using StringTokenizer.</p> |
| * |
| * <p>The separator is not included in the returned String array. |
| * Adjacent separators are treated as separators for empty tokens. |
| * For more control over the split use the StrTokenizer class.</p> |
| * |
| * <p>A <code>null</code> input String returns <code>null</code>.</p> |
| * |
| * <pre> |
| * StringUtils.splitPreserveAllTokens(null, *) = null |
| * StringUtils.splitPreserveAllTokens("", *) = [] |
| * StringUtils.splitPreserveAllTokens("a.b.c", '.') = ["a", "b", "c"] |
| * StringUtils.splitPreserveAllTokens("a..b.c", '.') = ["a", "", "b", "c"] |
| * StringUtils.splitPreserveAllTokens("a:b:c", '.') = ["a:b:c"] |
| * StringUtils.splitPreserveAllTokens("a\tb\nc", null) = ["a", "b", "c"] |
| * StringUtils.splitPreserveAllTokens("a b c", ' ') = ["a", "b", "c"] |
| * StringUtils.splitPreserveAllTokens("a b c ", ' ') = ["a", "b", "c", ""] |
| * StringUtils.splitPreserveAllTokens("a b c ", ' ') = ["a", "b", "c", "", ""] |
| * StringUtils.splitPreserveAllTokens(" a b c", ' ') = ["", a", "b", "c"] |
| * StringUtils.splitPreserveAllTokens(" a b c", ' ') = ["", "", a", "b", "c"] |
| * StringUtils.splitPreserveAllTokens(" a b c ", ' ') = ["", a", "b", "c", ""] |
| * </pre> |
| * |
| * @param str the String to parse, may be <code>null</code> |
| * @param separatorChar the character used as the delimiter, |
| * <code>null</code> splits on whitespace |
| * @return an array of parsed Strings, <code>null</code> if null String input |
| * @since 2.1 |
| */ |
| public static String[] splitPreserveAllTokens(String str, char separatorChar) { |
| return splitWorker(str, separatorChar, true); |
| } |
| |
| /** |
| * Performs the logic for the <code>split</code> and |
| * <code>splitPreserveAllTokens</code> methods that do not return a |
| * maximum array length. |
| * |
| * @param str the String to parse, may be <code>null</code> |
| * @param separatorChar the separate character |
| * @param preserveAllTokens if <code>true</code>, adjacent separators are |
| * treated as empty token separators; if <code>false</code>, adjacent |
| * separators are treated as one separator. |
| * @return an array of parsed Strings, <code>null</code> if null String input |
| */ |
| private static String[] splitWorker(String str, char separatorChar, boolean preserveAllTokens) { |
| // Performance tuned for 2.0 (JDK1.4) |
| |
| if (str == null) { |
| return null; |
| } |
| int len = str.length(); |
| if (len == 0) { |
| return ArrayUtils.EMPTY_STRING_ARRAY; |
| } |
| List list = new ArrayList(); |
| int i = 0, start = 0; |
| boolean match = false; |
| boolean lastMatch = false; |
| while (i < len) { |
| if (str.charAt(i) == separatorChar) { |
| if (match || preserveAllTokens) { |
| list.add(str.substring(start, i)); |
| match = false; |
| lastMatch = true; |
| } |
| start = ++i; |
| continue; |
| } else { |
| lastMatch = false; |
| } |
| match = true; |
| i++; |
| } |
| if (match || (preserveAllTokens && lastMatch)) { |
| list.add(str.substring(start, i)); |
| } |
| return (String[]) list.toArray(new String[list.size()]); |
| } |
| |
| /** |
| * <p>Splits the provided text into an array, separators specified, |
| * preserving all tokens, including empty tokens created by adjacent |
| * separators. This is an alternative to using StringTokenizer.</p> |
| * |
| * <p>The separator is not included in the returned String array. |
| * Adjacent separators are treated as separators for empty tokens. |
| * For more control over the split use the StrTokenizer class.</p> |
| * |
| * <p>A <code>null</code> input String returns <code>null</code>. |
| * A <code>null</code> separatorChars splits on whitespace.</p> |
| * |
| * <pre> |
| * StringUtils.splitPreserveAllTokens(null, *) = null |
| * StringUtils.splitPreserveAllTokens("", *) = [] |
| * StringUtils.splitPreserveAllTokens("abc def", null) = ["abc", "def"] |
| * StringUtils.splitPreserveAllTokens("abc def", " ") = ["abc", "def"] |
| * StringUtils.splitPreserveAllTokens("abc def", " ") = ["abc", "", def"] |
| * StringUtils.splitPreserveAllTokens("ab:cd:ef", ":") = ["ab", "cd", "ef"] |
| * StringUtils.splitPreserveAllTokens("ab:cd:ef:", ":") = ["ab", "cd", "ef", ""] |
| * StringUtils.splitPreserveAllTokens("ab:cd:ef::", ":") = ["ab", "cd", "ef", "", ""] |
| * StringUtils.splitPreserveAllTokens("ab::cd:ef", ":") = ["ab", "", cd", "ef"] |
| * StringUtils.splitPreserveAllTokens(":cd:ef", ":") = ["", cd", "ef"] |
| * StringUtils.splitPreserveAllTokens("::cd:ef", ":") = ["", "", cd", "ef"] |
| * StringUtils.splitPreserveAllTokens(":cd:ef:", ":") = ["", cd", "ef", ""] |
| * </pre> |
| * |
| * @param str the String to parse, may be <code>null</code> |
| * @param separatorChars the characters used as the delimiters, |
| * <code>null</code> splits on whitespace |
| * @return an array of parsed Strings, <code>null</code> if null String input |
| * @since 2.1 |
| */ |
| public static String[] splitPreserveAllTokens(String str, String separatorChars) { |
| return splitWorker(str, separatorChars, -1, true); |
| } |
| |
| /** |
| * <p>Splits the provided text into an array with a maximum length, |
| * separators specified, preserving all tokens, including empty tokens |
| * created by adjacent separators.</p> |
| * |
| * <p>The separator is not included in the returned String array. |
| * Adjacent separators are treated as separators for empty tokens. |
| * Adjacent separators are treated as one separator.</p> |
| * |
| * <p>A <code>null</code> input String returns <code>null</code>. |
| * A <code>null</code> separatorChars splits on whitespace.</p> |
| * |
| * <p>If more than <code>max</code> delimited substrings are found, the last |
| * returned string includes all characters after the first <code>max - 1</code> |
| * returned strings (including separator characters).</p> |
| * |
| * <pre> |
| * StringUtils.splitPreserveAllTokens(null, *, *) = null |
| * StringUtils.splitPreserveAllTokens("", *, *) = [] |
| * StringUtils.splitPreserveAllTokens("ab de fg", null, 0) = ["ab", "cd", "ef"] |
| * StringUtils.splitPreserveAllTokens("ab de fg", null, 0) = ["ab", "cd", "ef"] |
| * StringUtils.splitPreserveAllTokens("ab:cd:ef", ":", 0) = ["ab", "cd", "ef"] |
| * StringUtils.splitPreserveAllTokens("ab:cd:ef", ":", 2) = ["ab", "cd:ef"] |
| * StringUtils.splitPreserveAllTokens("ab de fg", null, 2) = ["ab", " de fg"] |
| * StringUtils.splitPreserveAllTokens("ab de fg", null, 3) = ["ab", "", " de fg"] |
| * StringUtils.splitPreserveAllTokens("ab de fg", null, 4) = ["ab", "", "", "de fg"] |
| * </pre> |
| * |
| * @param str the String to parse, may be <code>null</code> |
| * @param separatorChars the characters used as the delimiters, |
| * <code>null</code> splits on whitespace |
| * @param max the maximum number of elements to include in the |
| * array. A zero or negative value implies no limit |
| * @return an array of parsed Strings, <code>null</code> if null String input |
| * @since 2.1 |
| */ |
| public static String[] splitPreserveAllTokens(String str, String separatorChars, int max) { |
| return splitWorker(str, separatorChars, max, true); |
| } |
| |
| /** |
| * Performs the logic for the <code>split</code> and |
| * <code>splitPreserveAllTokens</code> methods that return a maximum array |
| * length. |
| * |
| * @param str the String to parse, may be <code>null</code> |
| * @param separatorChars the separate character |
| * @param max the maximum number of elements to include in the |
| * array. A zero or negative value implies no limit. |
| * @param preserveAllTokens if <code>true</code>, adjacent separators are |
| * treated as empty token separators; if <code>false</code>, adjacent |
| * separators are treated as one separator. |
| * @return an array of parsed Strings, <code>null</code> if null String input |
| */ |
| private static String[] splitWorker(String str, String separatorChars, int max, boolean preserveAllTokens) { |
| // Performance tuned for 2.0 (JDK1.4) |
| // Direct code is quicker than StringTokenizer. |
| // Also, StringTokenizer uses isSpace() not isWhitespace() |
| |
| if (str == null) { |
| return null; |
| } |
| int len = str.length(); |
| if (len == 0) { |
| return ArrayUtils.EMPTY_STRING_ARRAY; |
| } |
| List list = new ArrayList(); |
| int sizePlus1 = 1; |
| int i = 0, start = 0; |
| boolean match = false; |
| boolean lastMatch = false; |
| if (separatorChars == null) { |
| // Null separator means use whitespace |
| while (i < len) { |
| if (Character.isWhitespace(str.charAt(i))) { |
| if (match || preserveAllTokens) { |
| lastMatch = true; |
| if (sizePlus1++ == max) { |
| i = len; |
| lastMatch = false; |
| } |
| list.add(str.substring(start, i)); |
| match = false; |
| } |
| start = ++i; |
| continue; |
| } else { |
| lastMatch = false; |
| } |
| match = true; |
| i++; |
| } |
| } else if (separatorChars.length() == 1) { |
| // Optimise 1 character case |
| char sep = separatorChars.charAt(0); |
| while (i < len) { |
| if (str.charAt(i) == sep) { |
| if (match || preserveAllTokens) { |
| lastMatch = true; |
| if (sizePlus1++ == max) { |
| i = len; |
| lastMatch = false; |
| } |
| list.add(str.substring(start, i)); |
| match = false; |
| } |
| start = ++i; |
| continue; |
| } else { |
| lastMatch = false; |
| } |
| match = true; |
| i++; |
| } |
| } else { |
| // standard case |
| while (i < len) { |
| if (separatorChars.indexOf(str.charAt(i)) >= 0) { |
| if (match || preserveAllTokens) { |
| lastMatch = true; |
| if (sizePlus1++ == max) { |
| i = len; |
| lastMatch = false; |
| } |
| list.add(str.substring(start, i)); |
| match = false; |
| } |
| start = ++i; |
| continue; |
| } else { |
| lastMatch = false; |
| } |
| match = true; |
| i++; |
| } |
| } |
| if (match || (preserveAllTokens && lastMatch)) { |
| list.add(str.substring(start, i)); |
| } |
| return (String[]) list.toArray(new String[list.size()]); |
| } |
| |
| // Joining |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Concatenates elements of an array into a single String. |
| * Null objects or empty strings within the array are represented by |
| * empty strings.</p> |
| * |
| * <pre> |
| * StringUtils.concatenate(null) = null |
| * StringUtils.concatenate([]) = "" |
| * StringUtils.concatenate([null]) = "" |
| * StringUtils.concatenate(["a", "b", "c"]) = "abc" |
| * StringUtils.concatenate([null, "", "a"]) = "a" |
| * </pre> |
| * |
| * @param array the array of values to concatenate, may be null |
| * @return the concatenated String, <code>null</code> if null array input |
| * @deprecated Use the better named {@link #join(Object[])} instead. |
| * Method will be removed in Commons Lang 3.0. |
| */ |
| public static String concatenate(Object[] array) { |
| return join(array, null); |
| } |
| |
| /** |
| * <p>Joins the elements of the provided array into a single String |
| * containing the provided list of elements.</p> |
| * |
| * <p>No separator is added to the joined String. |
| * Null objects or empty strings within the array are represented by |
| * empty strings.</p> |
| * |
| * <pre> |
| * StringUtils.join(null) = null |
| * StringUtils.join([]) = "" |
| * StringUtils.join([null]) = "" |
| * StringUtils.join(["a", "b", "c"]) = "abc" |
| * StringUtils.join([null, "", "a"]) = "a" |
| * </pre> |
| * |
| * @param array the array of values to join together, may be null |
| * @return the joined String, <code>null</code> if null array input |
| * @since 2.0 |
| */ |
| public static String join(Object[] array) { |
| return join(array, null); |
| } |
| |
| /** |
| * <p>Joins the elements of the provided array into a single String |
| * containing the provided list of elements.</p> |
| * |
| * <p>No delimiter is added before or after the list. |
| * Null objects or empty strings within the array are represented by |
| * empty strings.</p> |
| * |
| * <pre> |
| * StringUtils.join(null, *) = null |
| * StringUtils.join([], *) = "" |
| * StringUtils.join([null], *) = "" |
| * StringUtils.join(["a", "b", "c"], ';') = "a;b;c" |
| * StringUtils.join(["a", "b", "c"], null) = "abc" |
| * StringUtils.join([null, "", "a"], ';') = ";;a" |
| * </pre> |
| * |
| * @param array the array of values to join together, may be null |
| * @param separator the separator character to use |
| * @return the joined String, <code>null</code> if null array input |
| * @since 2.0 |
| */ |
| public static String join(Object[] array, char separator) { |
| if (array == null) { |
| return null; |
| } |
| |
| return join(array, separator, 0, array.length); |
| } |
| |
| /** |
| * <p>Joins the elements of the provided array into a single String |
| * containing the provided list of elements.</p> |
| * |
| * <p>No delimiter is added before or after the list. |
| * Null objects or empty strings within the array are represented by |
| * empty strings.</p> |
| * |
| * <pre> |
| * StringUtils.join(null, *) = null |
| * StringUtils.join([], *) = "" |
| * StringUtils.join([null], *) = "" |
| * StringUtils.join(["a", "b", "c"], ';') = "a;b;c" |
| * StringUtils.join(["a", "b", "c"], null) = "abc" |
| * StringUtils.join([null, "", "a"], ';') = ";;a" |
| * </pre> |
| * |
| * @param array the array of values to join together, may be null |
| * @param separator the separator character to use |
| * @param startIndex the first index to start joining from. It is |
| * an error to pass in an end index past the end of the array |
| * @param endIndex the index to stop joining from (exclusive). It is |
| * an error to pass in an end index past the end of the array |
| * @return the joined String, <code>null</code> if null array input |
| * @since 2.0 |
| */ |
| public static String join(Object[] array, char separator, int startIndex, int endIndex) { |
| if (array == null) { |
| return null; |
| } |
| int bufSize = (endIndex - startIndex); |
| if (bufSize <= 0) { |
| return EMPTY; |
| } |
| |
| bufSize *= ((array[startIndex] == null ? 16 : array[startIndex].toString().length()) + 1); |
| StringBuffer buf = new StringBuffer(bufSize); |
| |
| for (int i = startIndex; i < endIndex; i++) { |
| if (i > startIndex) { |
| buf.append(separator); |
| } |
| if (array[i] != null) { |
| buf.append(array[i]); |
| } |
| } |
| return buf.toString(); |
| } |
| |
| |
| /** |
| * <p>Joins the elements of the provided array into a single String |
| * containing the provided list of elements.</p> |
| * |
| * <p>No delimiter is added before or after the list. |
| * A <code>null</code> separator is the same as an empty String (""). |
| * Null objects or empty strings within the array are represented by |
| * empty strings.</p> |
| * |
| * <pre> |
| * StringUtils.join(null, *) = null |
| * StringUtils.join([], *) = "" |
| * StringUtils.join([null], *) = "" |
| * StringUtils.join(["a", "b", "c"], "--") = "a--b--c" |
| * StringUtils.join(["a", "b", "c"], null) = "abc" |
| * StringUtils.join(["a", "b", "c"], "") = "abc" |
| * StringUtils.join([null, "", "a"], ',') = ",,a" |
| * </pre> |
| * |
| * @param array the array of values to join together, may be null |
| * @param separator the separator character to use, null treated as "" |
| * @return the joined String, <code>null</code> if null array input |
| */ |
| public static String join(Object[] array, String separator) { |
| if (array == null) { |
| return null; |
| } |
| return join(array, separator, 0, array.length); |
| } |
| |
| /** |
| * <p>Joins the elements of the provided array into a single String |
| * containing the provided list of elements.</p> |
| * |
| * <p>No delimiter is added before or after the list. |
| * A <code>null</code> separator is the same as an empty String (""). |
| * Null objects or empty strings within the array are represented by |
| * empty strings.</p> |
| * |
| * <pre> |
| * StringUtils.join(null, *) = null |
| * StringUtils.join([], *) = "" |
| * StringUtils.join([null], *) = "" |
| * StringUtils.join(["a", "b", "c"], "--") = "a--b--c" |
| * StringUtils.join(["a", "b", "c"], null) = "abc" |
| * StringUtils.join(["a", "b", "c"], "") = "abc" |
| * StringUtils.join([null, "", "a"], ',') = ",,a" |
| * </pre> |
| * |
| * @param array the array of values to join together, may be null |
| * @param separator the separator character to use, null treated as "" |
| * @param startIndex the first index to start joining from. It is |
| * an error to pass in an end index past the end of the array |
| * @param endIndex the index to stop joining from (exclusive). It is |
| * an error to pass in an end index past the end of the array |
| * @return the joined String, <code>null</code> if null array input |
| */ |
| public static String join(Object[] array, String separator, int startIndex, int endIndex) { |
| if (array == null) { |
| return null; |
| } |
| if (separator == null) { |
| separator = EMPTY; |
| } |
| |
| // endIndex - startIndex > 0: Len = NofStrings *(len(firstString) + len(separator)) |
| // (Assuming that all Strings are roughly equally long) |
| int bufSize = (endIndex - startIndex); |
| if (bufSize <= 0) { |
| return EMPTY; |
| } |
| |
| bufSize *= ((array[startIndex] == null ? 16 : array[startIndex].toString().length()) |
| + separator.length()); |
| |
| StringBuffer buf = new StringBuffer(bufSize); |
| |
| for (int i = startIndex; i < endIndex; i++) { |
| if (i > startIndex) { |
| buf.append(separator); |
| } |
| if (array[i] != null) { |
| buf.append(array[i]); |
| } |
| } |
| return buf.toString(); |
| } |
| |
| /** |
| * <p>Joins the elements of the provided <code>Iterator</code> into |
| * a single String containing the provided elements.</p> |
| * |
| * <p>No delimiter is added before or after the list. Null objects or empty |
| * strings within the iteration are represented by empty strings.</p> |
| * |
| * <p>See the examples here: {@link #join(Object[],char)}. </p> |
| * |
| * @param iterator the <code>Iterator</code> of values to join together, may be null |
| * @param separator the separator character to use |
| * @return the joined String, <code>null</code> if null iterator input |
| * @since 2.0 |
| */ |
| public static String join(Iterator iterator, char separator) { |
| |
| // handle null, zero and one elements before building a buffer |
| if (iterator == null) { |
| return null; |
| } |
| if (!iterator.hasNext()) { |
| return EMPTY; |
| } |
| Object first = iterator.next(); |
| if (!iterator.hasNext()) { |
| return ObjectUtils.toString(first); |
| } |
| |
| // two or more elements |
| StringBuffer buf = new StringBuffer(256); // Java default is 16, probably too small |
| if (first != null) { |
| buf.append(first); |
| } |
| |
| while (iterator.hasNext()) { |
| buf.append(separator); |
| Object obj = iterator.next(); |
| if (obj != null) { |
| buf.append(obj); |
| } |
| } |
| |
| return buf.toString(); |
| } |
| |
| /** |
| * <p>Joins the elements of the provided <code>Iterator</code> into |
| * a single String containing the provided elements.</p> |
| * |
| * <p>No delimiter is added before or after the list. |
| * A <code>null</code> separator is the same as an empty String ("").</p> |
| * |
| * <p>See the examples here: {@link #join(Object[],String)}. </p> |
| * |
| * @param iterator the <code>Iterator</code> of values to join together, may be null |
| * @param separator the separator character to use, null treated as "" |
| * @return the joined String, <code>null</code> if null iterator input |
| */ |
| public static String join(Iterator iterator, String separator) { |
| |
| // handle null, zero and one elements before building a buffer |
| if (iterator == null) { |
| return null; |
| } |
| if (!iterator.hasNext()) { |
| return EMPTY; |
| } |
| Object first = iterator.next(); |
| if (!iterator.hasNext()) { |
| return ObjectUtils.toString(first); |
| } |
| |
| // two or more elements |
| StringBuffer buf = new StringBuffer(256); // Java default is 16, probably too small |
| if (first != null) { |
| buf.append(first); |
| } |
| |
| while (iterator.hasNext()) { |
| if (separator != null) { |
| buf.append(separator); |
| } |
| Object obj = iterator.next(); |
| if (obj != null) { |
| buf.append(obj); |
| } |
| } |
| return buf.toString(); |
| } |
| |
| /** |
| * <p>Joins the elements of the provided <code>Collection</code> into |
| * a single String containing the provided elements.</p> |
| * |
| * <p>No delimiter is added before or after the list. Null objects or empty |
| * strings within the iteration are represented by empty strings.</p> |
| * |
| * <p>See the examples here: {@link #join(Object[],char)}. </p> |
| * |
| * @param collection the <code>Collection</code> of values to join together, may be null |
| * @param separator the separator character to use |
| * @return the joined String, <code>null</code> if null iterator input |
| * @since 2.3 |
| */ |
| public static String join(Collection collection, char separator) { |
| if (collection == null) { |
| return null; |
| } |
| return join(collection.iterator(), separator); |
| } |
| |
| /** |
| * <p>Joins the elements of the provided <code>Collection</code> into |
| * a single String containing the provided elements.</p> |
| * |
| * <p>No delimiter is added before or after the list. |
| * A <code>null</code> separator is the same as an empty String ("").</p> |
| * |
| * <p>See the examples here: {@link #join(Object[],String)}. </p> |
| * |
| * @param collection the <code>Collection</code> of values to join together, may be null |
| * @param separator the separator character to use, null treated as "" |
| * @return the joined String, <code>null</code> if null iterator input |
| * @since 2.3 |
| */ |
| public static String join(Collection collection, String separator) { |
| if (collection == null) { |
| return null; |
| } |
| return join(collection.iterator(), separator); |
| } |
| |
| // Delete |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Deletes all 'space' characters from a String as defined by |
| * {@link Character#isSpace(char)}.</p> |
| * |
| * <p>This is the only StringUtils method that uses the |
| * <code>isSpace</code> definition. You are advised to use |
| * {@link #deleteWhitespace(String)} instead as whitespace is much |
| * better localized.</p> |
| * |
| * <pre> |
| * StringUtils.deleteSpaces(null) = null |
| * StringUtils.deleteSpaces("") = "" |
| * StringUtils.deleteSpaces("abc") = "abc" |
| * StringUtils.deleteSpaces(" \t abc \n ") = "abc" |
| * StringUtils.deleteSpaces("ab c") = "abc" |
| * StringUtils.deleteSpaces("a\nb\tc ") = "abc" |
| * </pre> |
| * |
| * <p>Spaces are defined as <code>{' ', '\t', '\r', '\n', '\b'}</code> |
| * in line with the deprecated <code>isSpace</code> method.</p> |
| * |
| * @param str the String to delete spaces from, may be null |
| * @return the String without 'spaces', <code>null</code> if null String input |
| * @deprecated Use the better localized {@link #deleteWhitespace(String)}. |
| * Method will be removed in Commons Lang 3.0. |
| */ |
| public static String deleteSpaces(String str) { |
| if (str == null) { |
| return null; |
| } |
| return CharSetUtils.delete(str, " \t\r\n\b"); |
| } |
| |
| /** |
| * <p>Deletes all whitespaces from a String as defined by |
| * {@link Character#isWhitespace(char)}.</p> |
| * |
| * <pre> |
| * StringUtils.deleteWhitespace(null) = null |
| * StringUtils.deleteWhitespace("") = "" |
| * StringUtils.deleteWhitespace("abc") = "abc" |
| * StringUtils.deleteWhitespace(" ab c ") = "abc" |
| * </pre> |
| * |
| * @param str the String to delete whitespace from, may be null |
| * @return the String without whitespaces, <code>null</code> if null String input |
| */ |
| public static String deleteWhitespace(String str) { |
| if (isEmpty(str)) { |
| return str; |
| } |
| int sz = str.length(); |
| char[] chs = new char[sz]; |
| int count = 0; |
| for (int i = 0; i < sz; i++) { |
| if (!Character.isWhitespace(str.charAt(i))) { |
| chs[count++] = str.charAt(i); |
| } |
| } |
| if (count == sz) { |
| return str; |
| } |
| return new String(chs, 0, count); |
| } |
| |
| // Remove |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Removes a substring only if it is at the begining of a source string, |
| * otherwise returns the source string.</p> |
| * |
| * <p>A <code>null</code> source string will return <code>null</code>. |
| * An empty ("") source string will return the empty string. |
| * A <code>null</code> search string will return the source string.</p> |
| * |
| * <pre> |
| * StringUtils.removeStart(null, *) = null |
| * StringUtils.removeStart("", *) = "" |
| * StringUtils.removeStart(*, null) = * |
| * StringUtils.removeStart("www.domain.com", "www.") = "domain.com" |
| * StringUtils.removeStart("domain.com", "www.") = "domain.com" |
| * StringUtils.removeStart("www.domain.com", "domain") = "www.domain.com" |
| * StringUtils.removeStart("abc", "") = "abc" |
| * </pre> |
| * |
| * @param str the source String to search, may be null |
| * @param remove the String to search for and remove, may be null |
| * @return the substring with the string removed if found, |
| * <code>null</code> if null String input |
| * @since 2.1 |
| */ |
| public static String removeStart(String str, String remove) { |
| if (isEmpty(str) || isEmpty(remove)) { |
| return str; |
| } |
| if (str.startsWith(remove)){ |
| return str.substring(remove.length()); |
| } |
| return str; |
| } |
| |
| /** |
| * <p>Removes a substring only if it is at the end of a source string, |
| * otherwise returns the source string.</p> |
| * |
| * <p>A <code>null</code> source string will return <code>null</code>. |
| * An empty ("") source string will return the empty string. |
| * A <code>null</code> search string will return the source string.</p> |
| * |
| * <pre> |
| * StringUtils.removeEnd(null, *) = null |
| * StringUtils.removeEnd("", *) = "" |
| * StringUtils.removeEnd(*, null) = * |
| * StringUtils.removeEnd("www.domain.com", ".com.") = "www.domain.com." |
| * StringUtils.removeEnd("www.domain.com", ".com") = "www.domain" |
| * StringUtils.removeEnd("www.domain.com", "domain") = "www.domain.com" |
| * StringUtils.removeEnd("abc", "") = "abc" |
| * </pre> |
| * |
| * @param str the source String to search, may be null |
| * @param remove the String to search for and remove, may be null |
| * @return the substring with the string removed if found, |
| * <code>null</code> if null String input |
| * @since 2.1 |
| */ |
| public static String removeEnd(String str, String remove) { |
| if (isEmpty(str) || isEmpty(remove)) { |
| return str; |
| } |
| if (str.endsWith(remove)) { |
| return str.substring(0, str.length() - remove.length()); |
| } |
| return str; |
| } |
| |
| /** |
| * <p>Removes all occurances of a substring from within the source string.</p> |
| * |
| * <p>A <code>null</code> source string will return <code>null</code>. |
| * An empty ("") source string will return the empty string. |
| * A <code>null</code> remove string will return the source string. |
| * An empty ("") remove string will return the source string.</p> |
| * |
| * <pre> |
| * StringUtils.remove(null, *) = null |
| * StringUtils.remove("", *) = "" |
| * StringUtils.remove(*, null) = * |
| * StringUtils.remove(*, "") = * |
| * StringUtils.remove("queued", "ue") = "qd" |
| * StringUtils.remove("queued", "zz") = "queued" |
| * </pre> |
| * |
| * @param str the source String to search, may be null |
| * @param remove the String to search for and remove, may be null |
| * @return the substring with the string removed if found, |
| * <code>null</code> if null String input |
| * @since 2.1 |
| */ |
| public static String remove(String str, String remove) { |
| if (isEmpty(str) || isEmpty(remove)) { |
| return str; |
| } |
| return replace(str, remove, "", -1); |
| } |
| |
| /** |
| * <p>Removes all occurances of a character from within the source string.</p> |
| * |
| * <p>A <code>null</code> source string will return <code>null</code>. |
| * An empty ("") source string will return the empty string.</p> |
| * |
| * <pre> |
| * StringUtils.remove(null, *) = null |
| * StringUtils.remove("", *) = "" |
| * StringUtils.remove("queued", 'u') = "qeed" |
| * StringUtils.remove("queued", 'z') = "queued" |
| * </pre> |
| * |
| * @param str the source String to search, may be null |
| * @param remove the char to search for and remove, may be null |
| * @return the substring with the char removed if found, |
| * <code>null</code> if null String input |
| * @since 2.1 |
| */ |
| public static String remove(String str, char remove) { |
| if (isEmpty(str) || str.indexOf(remove) == -1) { |
| return str; |
| } |
| char[] chars = str.toCharArray(); |
| int pos = 0; |
| for (int i = 0; i < chars.length; i++) { |
| if (chars[i] != remove) { |
| chars[pos++] = chars[i]; |
| } |
| } |
| return new String(chars, 0, pos); |
| } |
| |
| // Replacing |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Replaces a String with another String inside a larger String, once.</p> |
| * |
| * <p>A <code>null</code> reference passed to this method is a no-op.</p> |
| * |
| * <pre> |
| * StringUtils.replaceOnce(null, *, *) = null |
| * StringUtils.replaceOnce("", *, *) = "" |
| * StringUtils.replaceOnce("any", null, *) = "any" |
| * StringUtils.replaceOnce("any", *, null) = "any" |
| * StringUtils.replaceOnce("any", "", *) = "any" |
| * StringUtils.replaceOnce("aba", "a", null) = "aba" |
| * StringUtils.replaceOnce("aba", "a", "") = "ba" |
| * StringUtils.replaceOnce("aba", "a", "z") = "zba" |
| * </pre> |
| * |
| * @see #replace(String text, String repl, String with, int max) |
| * @param text text to search and replace in, may be null |
| * @param repl the String to search for, may be null |
| * @param with the String to replace with, may be null |
| * @return the text with any replacements processed, |
| * <code>null</code> if null String input |
| */ |
| public static String replaceOnce(String text, String repl, String with) { |
| return replace(text, repl, with, 1); |
| } |
| |
| /** |
| * <p>Replaces all occurrences of a String within another String.</p> |
| * |
| * <p>A <code>null</code> reference passed to this method is a no-op.</p> |
| * |
| * <pre> |
| * StringUtils.replace(null, *, *) = null |
| * StringUtils.replace("", *, *) = "" |
| * StringUtils.replace("any", null, *) = "any" |
| * StringUtils.replace("any", *, null) = "any" |
| * StringUtils.replace("any", "", *) = "any" |
| * StringUtils.replace("aba", "a", null) = "aba" |
| * StringUtils.replace("aba", "a", "") = "b" |
| * StringUtils.replace("aba", "a", "z") = "zbz" |
| * </pre> |
| * |
| * @see #replace(String text, String repl, String with, int max) |
| * @param text text to search and replace in, may be null |
| * @param repl the String to search for, may be null |
| * @param with the String to replace with, may be null |
| * @return the text with any replacements processed, |
| * <code>null</code> if null String input |
| */ |
| public static String replace(String text, String repl, String with) { |
| return replace(text, repl, with, -1); |
| } |
| |
| /** |
| * <p>Replaces a String with another String inside a larger String, |
| * for the first <code>max</code> values of the search String.</p> |
| * |
| * <p>A <code>null</code> reference passed to this method is a no-op.</p> |
| * |
| * <pre> |
| * StringUtils.replace(null, *, *, *) = null |
| * StringUtils.replace("", *, *, *) = "" |
| * StringUtils.replace("any", null, *, *) = "any" |
| * StringUtils.replace("any", *, null, *) = "any" |
| * StringUtils.replace("any", "", *, *) = "any" |
| * StringUtils.replace("any", *, *, 0) = "any" |
| * StringUtils.replace("abaa", "a", null, -1) = "abaa" |
| * StringUtils.replace("abaa", "a", "", -1) = "b" |
| * StringUtils.replace("abaa", "a", "z", 0) = "abaa" |
| * StringUtils.replace("abaa", "a", "z", 1) = "zbaa" |
| * StringUtils.replace("abaa", "a", "z", 2) = "zbza" |
| * StringUtils.replace("abaa", "a", "z", -1) = "zbzz" |
| * </pre> |
| * |
| * @param text text to search and replace in, may be null |
| * @param repl the String to search for, may be null |
| * @param with the String to replace with, may be null |
| * @param max maximum number of values to replace, or <code>-1</code> if no maximum |
| * @return the text with any replacements processed, |
| * <code>null</code> if null String input |
| */ |
| public static String replace(String text, String repl, String with, int max) { |
| if (isEmpty(text) || isEmpty(repl) || with == null || max == 0) { |
| return text; |
| } |
| int start = 0; |
| int end = text.indexOf(repl, start); |
| if (end == -1) { |
| return text; |
| } |
| int replLength = repl.length(); |
| int increase = with.length() - replLength; |
| increase = (increase < 0 ? 0 : increase); |
| increase *= (max < 0 ? 16 : (max > 64 ? 64 : max)); |
| StringBuffer buf = new StringBuffer(text.length() + increase); |
| while (end != -1) { |
| buf.append(text.substring(start, end)).append(with); |
| start = end + replLength; |
| if (--max == 0) { |
| break; |
| } |
| end = text.indexOf(repl, start); |
| } |
| buf.append(text.substring(start)); |
| return buf.toString(); |
| } |
| |
| // Replace, character based |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Replaces all occurrences of a character in a String with another. |
| * This is a null-safe version of {@link String#replace(char, char)}.</p> |
| * |
| * <p>A <code>null</code> string input returns <code>null</code>. |
| * An empty ("") string input returns an empty string.</p> |
| * |
| * <pre> |
| * StringUtils.replaceChars(null, *, *) = null |
| * StringUtils.replaceChars("", *, *) = "" |
| * StringUtils.replaceChars("abcba", 'b', 'y') = "aycya" |
| * StringUtils.replaceChars("abcba", 'z', 'y') = "abcba" |
| * </pre> |
| * |
| * @param str String to replace characters in, may be null |
| * @param searchChar the character to search for, may be null |
| * @param replaceChar the character to replace, may be null |
| * @return modified String, <code>null</code> if null string input |
| * @since 2.0 |
| */ |
| public static String replaceChars(String str, char searchChar, char replaceChar) { |
| if (str == null) { |
| return null; |
| } |
| return str.replace(searchChar, replaceChar); |
| } |
| |
| /** |
| * <p>Replaces multiple characters in a String in one go. |
| * This method can also be used to delete characters.</p> |
| * |
| * <p>For example:<br /> |
| * <code>replaceChars("hello", "ho", "jy") = jelly</code>.</p> |
| * |
| * <p>A <code>null</code> string input returns <code>null</code>. |
| * An empty ("") string input returns an empty string. |
| * A null or empty set of search characters returns the input string.</p> |
| * |
| * <p>The length of the search characters should normally equal the length |
| * of the replace characters. |
| * If the search characters is longer, then the extra search characters |
| * are deleted. |
| * If the search characters is shorter, then the extra replace characters |
| * are ignored.</p> |
| * |
| * <pre> |
| * StringUtils.replaceChars(null, *, *) = null |
| * StringUtils.replaceChars("", *, *) = "" |
| * StringUtils.replaceChars("abc", null, *) = "abc" |
| * StringUtils.replaceChars("abc", "", *) = "abc" |
| * StringUtils.replaceChars("abc", "b", null) = "ac" |
| * StringUtils.replaceChars("abc", "b", "") = "ac" |
| * StringUtils.replaceChars("abcba", "bc", "yz") = "ayzya" |
| * StringUtils.replaceChars("abcba", "bc", "y") = "ayya" |
| * StringUtils.replaceChars("abcba", "bc", "yzx") = "ayzya" |
| * </pre> |
| * |
| * @param str String to replace characters in, may be null |
| * @param searchChars a set of characters to search for, may be null |
| * @param replaceChars a set of characters to replace, may be null |
| * @return modified String, <code>null</code> if null string input |
| * @since 2.0 |
| */ |
| public static String replaceChars(String str, String searchChars, String replaceChars) { |
| if (isEmpty(str) || isEmpty(searchChars)) { |
| return str; |
| } |
| if (replaceChars == null) { |
| replaceChars = ""; |
| } |
| boolean modified = false; |
| int replaceCharsLength = replaceChars.length(); |
| int strLength = str.length(); |
| StringBuffer buf = new StringBuffer(strLength); |
| for (int i = 0; i < strLength; i++) { |
| char ch = str.charAt(i); |
| int index = searchChars.indexOf(ch); |
| if (index >= 0) { |
| modified = true; |
| if (index < replaceCharsLength) { |
| buf.append(replaceChars.charAt(index)); |
| } |
| } else { |
| buf.append(ch); |
| } |
| } |
| if (modified) { |
| return buf.toString(); |
| } else { |
| return str; |
| } |
| } |
| |
| // Overlay |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Overlays part of a String with another String.</p> |
| * |
| * <pre> |
| * StringUtils.overlayString(null, *, *, *) = NullPointerException |
| * StringUtils.overlayString(*, null, *, *) = NullPointerException |
| * StringUtils.overlayString("", "abc", 0, 0) = "abc" |
| * StringUtils.overlayString("abcdef", null, 2, 4) = "abef" |
| * StringUtils.overlayString("abcdef", "", 2, 4) = "abef" |
| * StringUtils.overlayString("abcdef", "zzzz", 2, 4) = "abzzzzef" |
| * StringUtils.overlayString("abcdef", "zzzz", 4, 2) = "abcdzzzzcdef" |
| * StringUtils.overlayString("abcdef", "zzzz", -1, 4) = IndexOutOfBoundsException |
| * StringUtils.overlayString("abcdef", "zzzz", 2, 8) = IndexOutOfBoundsException |
| * </pre> |
| * |
| * @param text the String to do overlaying in, may be null |
| * @param overlay the String to overlay, may be null |
| * @param start the position to start overlaying at, must be valid |
| * @param end the position to stop overlaying before, must be valid |
| * @return overlayed String, <code>null</code> if null String input |
| * @throws NullPointerException if text or overlay is null |
| * @throws IndexOutOfBoundsException if either position is invalid |
| * @deprecated Use better named {@link #overlay(String, String, int, int)} instead. |
| * Method will be removed in Commons Lang 3.0. |
| */ |
| public static String overlayString(String text, String overlay, int start, int end) { |
| return new StringBuffer(start + overlay.length() + text.length() - end + 1) |
| .append(text.substring(0, start)) |
| .append(overlay) |
| .append(text.substring(end)) |
| .toString(); |
| } |
| |
| /** |
| * <p>Overlays part of a String with another String.</p> |
| * |
| * <p>A <code>null</code> string input returns <code>null</code>. |
| * A negative index is treated as zero. |
| * An index greater than the string length is treated as the string length. |
| * The start index is always the smaller of the two indices.</p> |
| * |
| * <pre> |
| * StringUtils.overlay(null, *, *, *) = null |
| * StringUtils.overlay("", "abc", 0, 0) = "abc" |
| * StringUtils.overlay("abcdef", null, 2, 4) = "abef" |
| * StringUtils.overlay("abcdef", "", 2, 4) = "abef" |
| * StringUtils.overlay("abcdef", "", 4, 2) = "abef" |
| * StringUtils.overlay("abcdef", "zzzz", 2, 4) = "abzzzzef" |
| * StringUtils.overlay("abcdef", "zzzz", 4, 2) = "abzzzzef" |
| * StringUtils.overlay("abcdef", "zzzz", -1, 4) = "zzzzef" |
| * StringUtils.overlay("abcdef", "zzzz", 2, 8) = "abzzzz" |
| * StringUtils.overlay("abcdef", "zzzz", -2, -3) = "zzzzabcdef" |
| * StringUtils.overlay("abcdef", "zzzz", 8, 10) = "abcdefzzzz" |
| * </pre> |
| * |
| * @param str the String to do overlaying in, may be null |
| * @param overlay the String to overlay, may be null |
| * @param start the position to start overlaying at |
| * @param end the position to stop overlaying before |
| * @return overlayed String, <code>null</code> if null String input |
| * @since 2.0 |
| */ |
| public static String overlay(String str, String overlay, int start, int end) { |
| if (str == null) { |
| return null; |
| } |
| if (overlay == null) { |
| overlay = EMPTY; |
| } |
| int len = str.length(); |
| if (start < 0) { |
| start = 0; |
| } |
| if (start > len) { |
| start = len; |
| } |
| if (end < 0) { |
| end = 0; |
| } |
| if (end > len) { |
| end = len; |
| } |
| if (start > end) { |
| int temp = start; |
| start = end; |
| end = temp; |
| } |
| return new StringBuffer(len + start - end + overlay.length() + 1) |
| .append(str.substring(0, start)) |
| .append(overlay) |
| .append(str.substring(end)) |
| .toString(); |
| } |
| |
| // Chomping |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Removes one newline from end of a String if it's there, |
| * otherwise leave it alone. A newline is "<code>\n</code>", |
| * "<code>\r</code>", or "<code>\r\n</code>".</p> |
| * |
| * <p>NOTE: This method changed in 2.0. |
| * It now more closely matches Perl chomp.</p> |
| * |
| * <pre> |
| * StringUtils.chomp(null) = null |
| * StringUtils.chomp("") = "" |
| * StringUtils.chomp("abc \r") = "abc " |
| * StringUtils.chomp("abc\n") = "abc" |
| * StringUtils.chomp("abc\r\n") = "abc" |
| * StringUtils.chomp("abc\r\n\r\n") = "abc\r\n" |
| * StringUtils.chomp("abc\n\r") = "abc\n" |
| * StringUtils.chomp("abc\n\rabc") = "abc\n\rabc" |
| * StringUtils.chomp("\r") = "" |
| * StringUtils.chomp("\n") = "" |
| * StringUtils.chomp("\r\n") = "" |
| * </pre> |
| * |
| * @param str the String to chomp a newline from, may be null |
| * @return String without newline, <code>null</code> if null String input |
| */ |
| public static String chomp(String str) { |
| if (isEmpty(str)) { |
| return str; |
| } |
| |
| if (str.length() == 1) { |
| char ch = str.charAt(0); |
| if (ch == CharUtils.CR || ch == CharUtils.LF) { |
| return EMPTY; |
| } else { |
| return str; |
| } |
| } |
| |
| int lastIdx = str.length() - 1; |
| char last = str.charAt(lastIdx); |
| |
| if (last == CharUtils.LF) { |
| if (str.charAt(lastIdx - 1) == CharUtils.CR) { |
| lastIdx--; |
| } |
| } else if (last != CharUtils.CR) { |
| lastIdx++; |
| } |
| return str.substring(0, lastIdx); |
| } |
| |
| /** |
| * <p>Removes <code>separator</code> from the end of |
| * <code>str</code> if it's there, otherwise leave it alone.</p> |
| * |
| * <p>NOTE: This method changed in version 2.0. |
| * It now more closely matches Perl chomp. |
| * For the previous behavior, use {@link #substringBeforeLast(String, String)}. |
| * This method uses {@link String#endsWith(String)}.</p> |
| * |
| * <pre> |
| * StringUtils.chomp(null, *) = null |
| * StringUtils.chomp("", *) = "" |
| * StringUtils.chomp("foobar", "bar") = "foo" |
| * StringUtils.chomp("foobar", "baz") = "foobar" |
| * StringUtils.chomp("foo", "foo") = "" |
| * StringUtils.chomp("foo ", "foo") = "foo " |
| * StringUtils.chomp(" foo", "foo") = " " |
| * StringUtils.chomp("foo", "foooo") = "foo" |
| * StringUtils.chomp("foo", "") = "foo" |
| * StringUtils.chomp("foo", null) = "foo" |
| * </pre> |
| * |
| * @param str the String to chomp from, may be null |
| * @param separator separator String, may be null |
| * @return String without trailing separator, <code>null</code> if null String input |
| */ |
| public static String chomp(String str, String separator) { |
| if (isEmpty(str) || separator == null) { |
| return str; |
| } |
| if (str.endsWith(separator)) { |
| return str.substring(0, str.length() - separator.length()); |
| } |
| return str; |
| } |
| |
| /** |
| * <p>Remove any "\n" if and only if it is at the end |
| * of the supplied String.</p> |
| * |
| * @param str the String to chomp from, must not be null |
| * @return String without chomped ending |
| * @throws NullPointerException if str is <code>null</code> |
| * @deprecated Use {@link #chomp(String)} instead. |
| * Method will be removed in Commons Lang 3.0. |
| */ |
| public static String chompLast(String str) { |
| return chompLast(str, "\n"); |
| } |
| |
| /** |
| * <p>Remove a value if and only if the String ends with that value.</p> |
| * |
| * @param str the String to chomp from, must not be null |
| * @param sep the String to chomp, must not be null |
| * @return String without chomped ending |
| * @throws NullPointerException if str or sep is <code>null</code> |
| * @deprecated Use {@link #chomp(String,String)} instead. |
| * Method will be removed in Commons Lang 3.0. |
| */ |
| public static String chompLast(String str, String sep) { |
| if (str.length() == 0) { |
| return str; |
| } |
| String sub = str.substring(str.length() - sep.length()); |
| if (sep.equals(sub)) { |
| return str.substring(0, str.length() - sep.length()); |
| } else { |
| return str; |
| } |
| } |
| |
| /** |
| * <p>Remove everything and return the last value of a supplied String, and |
| * everything after it from a String.</p> |
| * |
| * @param str the String to chomp from, must not be null |
| * @param sep the String to chomp, must not be null |
| * @return String chomped |
| * @throws NullPointerException if str or sep is <code>null</code> |
| * @deprecated Use {@link #substringAfterLast(String, String)} instead |
| * (although this doesn't include the separator) |
| * Method will be removed in Commons Lang 3.0. |
| */ |
| public static String getChomp(String str, String sep) { |
| int idx = str.lastIndexOf(sep); |
| if (idx == str.length() - sep.length()) { |
| return sep; |
| } else if (idx != -1) { |
| return str.substring(idx); |
| } else { |
| return EMPTY; |
| } |
| } |
| |
| /** |
| * <p>Remove the first value of a supplied String, and everything before it |
| * from a String.</p> |
| * |
| * @param str the String to chomp from, must not be null |
| * @param sep the String to chomp, must not be null |
| * @return String without chomped beginning |
| * @throws NullPointerException if str or sep is <code>null</code> |
| * @deprecated Use {@link #substringAfter(String,String)} instead. |
| * Method will be removed in Commons Lang 3.0. |
| */ |
| public static String prechomp(String str, String sep) { |
| int idx = str.indexOf(sep); |
| if (idx != -1) { |
| return str.substring(idx + sep.length()); |
| } else { |
| return str; |
| } |
| } |
| |
| /** |
| * <p>Remove and return everything before the first value of a |
| * supplied String from another String.</p> |
| * |
| * @param str the String to chomp from, must not be null |
| * @param sep the String to chomp, must not be null |
| * @return String prechomped |
| * @throws NullPointerException if str or sep is <code>null</code> |
| * @deprecated Use {@link #substringBefore(String,String)} instead |
| * (although this doesn't include the separator). |
| * Method will be removed in Commons Lang 3.0. |
| */ |
| public static String getPrechomp(String str, String sep) { |
| int idx = str.indexOf(sep); |
| if (idx != -1) { |
| return str.substring(0, idx + sep.length()); |
| } else { |
| return EMPTY; |
| } |
| } |
| |
| // Chopping |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Remove the last character from a String.</p> |
| * |
| * <p>If the String ends in <code>\r\n</code>, then remove both |
| * of them.</p> |
| * |
| * <pre> |
| * StringUtils.chop(null) = null |
| * StringUtils.chop("") = "" |
| * StringUtils.chop("abc \r") = "abc " |
| * StringUtils.chop("abc\n") = "abc" |
| * StringUtils.chop("abc\r\n") = "abc" |
| * StringUtils.chop("abc") = "ab" |
| * StringUtils.chop("abc\nabc") = "abc\nab" |
| * StringUtils.chop("a") = "" |
| * StringUtils.chop("\r") = "" |
| * StringUtils.chop("\n") = "" |
| * StringUtils.chop("\r\n") = "" |
| * </pre> |
| * |
| * @param str the String to chop last character from, may be null |
| * @return String without last character, <code>null</code> if null String input |
| */ |
| public static String chop(String str) { |
| if (str == null) { |
| return null; |
| } |
| int strLen = str.length(); |
| if (strLen < 2) { |
| return EMPTY; |
| } |
| int lastIdx = strLen - 1; |
| String ret = str.substring(0, lastIdx); |
| char last = str.charAt(lastIdx); |
| if (last == CharUtils.LF) { |
| if (ret.charAt(lastIdx - 1) == CharUtils.CR) { |
| return ret.substring(0, lastIdx - 1); |
| } |
| } |
| return ret; |
| } |
| |
| /** |
| * <p>Removes <code>\n</code> from end of a String if it's there. |
| * If a <code>\r</code> precedes it, then remove that too.</p> |
| * |
| * @param str the String to chop a newline from, must not be null |
| * @return String without newline |
| * @throws NullPointerException if str is <code>null</code> |
| * @deprecated Use {@link #chomp(String)} instead. |
| * Method will be removed in Commons Lang 3.0. |
| */ |
| public static String chopNewline(String str) { |
| int lastIdx = str.length() - 1; |
| if (lastIdx <= 0) { |
| return EMPTY; |
| } |
| char last = str.charAt(lastIdx); |
| if (last == CharUtils.LF) { |
| if (str.charAt(lastIdx - 1) == CharUtils.CR) { |
| lastIdx--; |
| } |
| } else { |
| lastIdx++; |
| } |
| return str.substring(0, lastIdx); |
| } |
| |
| // Conversion |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Escapes any values it finds into their String form.</p> |
| * |
| * <p>So a tab becomes the characters <code>'\\'</code> and |
| * <code>'t'</code>.</p> |
| * |
| * <p>As of Lang 2.0, this calls {@link StringEscapeUtils#escapeJava(String)} |
| * behind the scenes. |
| * </p> |
| * @see StringEscapeUtils#escapeJava(java.lang.String) |
| * @param str String to escape values in |
| * @return String with escaped values |
| * @throws NullPointerException if str is <code>null</code> |
| * @deprecated Use {@link StringEscapeUtils#escapeJava(String)} |
| * This method will be removed in Commons Lang 3.0 |
| */ |
| public static String escape(String str) { |
| return StringEscapeUtils.escapeJava(str); |
| } |
| |
| // Padding |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Repeat a String <code>repeat</code> times to form a |
| * new String.</p> |
| * |
| * <pre> |
| * StringUtils.repeat(null, 2) = null |
| * StringUtils.repeat("", 0) = "" |
| * StringUtils.repeat("", 2) = "" |
| * StringUtils.repeat("a", 3) = "aaa" |
| * StringUtils.repeat("ab", 2) = "abab" |
| * StringUtils.repeat("a", -2) = "" |
| * </pre> |
| * |
| * @param str the String to repeat, may be null |
| * @param repeat number of times to repeat str, negative treated as zero |
| * @return a new String consisting of the original String repeated, |
| * <code>null</code> if null String input |
| */ |
| public static String repeat(String str, int repeat) { |
| // Performance tuned for 2.0 (JDK1.4) |
| |
| if (str == null) { |
| return null; |
| } |
| if (repeat <= 0) { |
| return EMPTY; |
| } |
| int inputLength = str.length(); |
| if (repeat == 1 || inputLength == 0) { |
| return str; |
| } |
| if (inputLength == 1 && repeat <= PAD_LIMIT) { |
| return padding(repeat, str.charAt(0)); |
| } |
| |
| int outputLength = inputLength * repeat; |
| switch (inputLength) { |
| case 1 : |
| char ch = str.charAt(0); |
| char[] output1 = new char[outputLength]; |
| for (int i = repeat - 1; i >= 0; i--) { |
| output1[i] = ch; |
| } |
| return new String(output1); |
| case 2 : |
| char ch0 = str.charAt(0); |
| char ch1 = str.charAt(1); |
| char[] output2 = new char[outputLength]; |
| for (int i = repeat * 2 - 2; i >= 0; i--, i--) { |
| output2[i] = ch0; |
| output2[i + 1] = ch1; |
| } |
| return new String(output2); |
| default : |
| StringBuffer buf = new StringBuffer(outputLength); |
| for (int i = 0; i < repeat; i++) { |
| buf.append(str); |
| } |
| return buf.toString(); |
| } |
| } |
| |
| /** |
| * <p>Returns padding using the specified delimiter repeated |
| * to a given length.</p> |
| * |
| * <pre> |
| * StringUtils.padding(0, 'e') = "" |
| * StringUtils.padding(3, 'e') = "eee" |
| * StringUtils.padding(-2, 'e') = IndexOutOfBoundsException |
| * </pre> |
| * |
| * <p>Note: this method doesn't not support padding with |
| * <a href="http://www.unicode.org/glossary/#supplementary_character">Unicode Supplementary Characters</a> |
| * as they require a pair of <code>char</code>s to be represented. |
| * If you are needing to support full I18N of your applications |
| * consider using {@link #repeat(String, int)} instead. |
| * </p> |
| * |
| * @param repeat number of times to repeat delim |
| * @param padChar character to repeat |
| * @return String with repeated character |
| * @throws IndexOutOfBoundsException if <code>repeat < 0</code> |
| * @see #repeat(String, int) |
| */ |
| private static String padding(int repeat, char padChar) throws IndexOutOfBoundsException { |
| if (repeat < 0) { |
| throw new IndexOutOfBoundsException("Cannot pad a negative amount: " + repeat); |
| } |
| final char[] buf = new char[repeat]; |
| for (int i = 0; i < buf.length; i++) { |
| buf[i] = padChar; |
| } |
| return new String(buf); |
| } |
| |
| /** |
| * <p>Right pad a String with spaces (' ').</p> |
| * |
| * <p>The String is padded to the size of <code>size</code>.</p> |
| * |
| * <pre> |
| * StringUtils.rightPad(null, *) = null |
| * StringUtils.rightPad("", 3) = " " |
| * StringUtils.rightPad("bat", 3) = "bat" |
| * StringUtils.rightPad("bat", 5) = "bat " |
| * StringUtils.rightPad("bat", 1) = "bat" |
| * StringUtils.rightPad("bat", -1) = "bat" |
| * </pre> |
| * |
| * @param str the String to pad out, may be null |
| * @param size the size to pad to |
| * @return right padded String or original String if no padding is necessary, |
| * <code>null</code> if null String input |
| */ |
| public static String rightPad(String str, int size) { |
| return rightPad(str, size, ' '); |
| } |
| |
| /** |
| * <p>Right pad a String with a specified character.</p> |
| * |
| * <p>The String is padded to the size of <code>size</code>.</p> |
| * |
| * <pre> |
| * StringUtils.rightPad(null, *, *) = null |
| * StringUtils.rightPad("", 3, 'z') = "zzz" |
| * StringUtils.rightPad("bat", 3, 'z') = "bat" |
| * StringUtils.rightPad("bat", 5, 'z') = "batzz" |
| * StringUtils.rightPad("bat", 1, 'z') = "bat" |
| * StringUtils.rightPad("bat", -1, 'z') = "bat" |
| * </pre> |
| * |
| * @param str the String to pad out, may be null |
| * @param size the size to pad to |
| * @param padChar the character to pad with |
| * @return right padded String or original String if no padding is necessary, |
| * <code>null</code> if null String input |
| * @since 2.0 |
| */ |
| public static String rightPad(String str, int size, char padChar) { |
| if (str == null) { |
| return null; |
| } |
| int pads = size - str.length(); |
| if (pads <= 0) { |
| return str; // returns original String when possible |
| } |
| if (pads > PAD_LIMIT) { |
| return rightPad(str, size, String.valueOf(padChar)); |
| } |
| return str.concat(padding(pads, padChar)); |
| } |
| |
| /** |
| * <p>Right pad a String with a specified String.</p> |
| * |
| * <p>The String is padded to the size of <code>size</code>.</p> |
| * |
| * <pre> |
| * StringUtils.rightPad(null, *, *) = null |
| * StringUtils.rightPad("", 3, "z") = "zzz" |
| * StringUtils.rightPad("bat", 3, "yz") = "bat" |
| * StringUtils.rightPad("bat", 5, "yz") = "batyz" |
| * StringUtils.rightPad("bat", 8, "yz") = "batyzyzy" |
| * StringUtils.rightPad("bat", 1, "yz") = "bat" |
| * StringUtils.rightPad("bat", -1, "yz") = "bat" |
| * StringUtils.rightPad("bat", 5, null) = "bat " |
| * StringUtils.rightPad("bat", 5, "") = "bat " |
| * </pre> |
| * |
| * @param str the String to pad out, may be null |
| * @param size the size to pad to |
| * @param padStr the String to pad with, null or empty treated as single space |
| * @return right padded String or original String if no padding is necessary, |
| * <code>null</code> if null String input |
| */ |
| public static String rightPad(String str, int size, String padStr) { |
| if (str == null) { |
| return null; |
| } |
| if (isEmpty(padStr)) { |
| padStr = " "; |
| } |
| int padLen = padStr.length(); |
| int strLen = str.length(); |
| int pads = size - strLen; |
| if (pads <= 0) { |
| return str; // returns original String when possible |
| } |
| if (padLen == 1 && pads <= PAD_LIMIT) { |
| return rightPad(str, size, padStr.charAt(0)); |
| } |
| |
| if (pads == padLen) { |
| return str.concat(padStr); |
| } else if (pads < padLen) { |
| return str.concat(padStr.substring(0, pads)); |
| } else { |
| char[] padding = new char[pads]; |
| char[] padChars = padStr.toCharArray(); |
| for (int i = 0; i < pads; i++) { |
| padding[i] = padChars[i % padLen]; |
| } |
| return str.concat(new String(padding)); |
| } |
| } |
| |
| /** |
| * <p>Left pad a String with spaces (' ').</p> |
| * |
| * <p>The String is padded to the size of <code>size<code>.</p> |
| * |
| * <pre> |
| * StringUtils.leftPad(null, *) = null |
| * StringUtils.leftPad("", 3) = " " |
| * StringUtils.leftPad("bat", 3) = "bat" |
| * StringUtils.leftPad("bat", 5) = " bat" |
| * StringUtils.leftPad("bat", 1) = "bat" |
| * StringUtils.leftPad("bat", -1) = "bat" |
| * </pre> |
| * |
| * @param str the String to pad out, may be null |
| * @param size the size to pad to |
| * @return left padded String or original String if no padding is necessary, |
| * <code>null</code> if null String input |
| */ |
| public static String leftPad(String str, int size) { |
| return leftPad(str, size, ' '); |
| } |
| |
| /** |
| * <p>Left pad a String with a specified character.</p> |
| * |
| * <p>Pad to a size of <code>size</code>.</p> |
| * |
| * <pre> |
| * StringUtils.leftPad(null, *, *) = null |
| * StringUtils.leftPad("", 3, 'z') = "zzz" |
| * StringUtils.leftPad("bat", 3, 'z') = "bat" |
| * StringUtils.leftPad("bat", 5, 'z') = "zzbat" |
| * StringUtils.leftPad("bat", 1, 'z') = "bat" |
| * StringUtils.leftPad("bat", -1, 'z') = "bat" |
| * </pre> |
| * |
| * @param str the String to pad out, may be null |
| * @param size the size to pad to |
| * @param padChar the character to pad with |
| * @return left padded String or original String if no padding is necessary, |
| * <code>null</code> if null String input |
| * @since 2.0 |
| */ |
| public static String leftPad(String str, int size, char padChar) { |
| if (str == null) { |
| return null; |
| } |
| int pads = size - str.length(); |
| if (pads <= 0) { |
| return str; // returns original String when possible |
| } |
| if (pads > PAD_LIMIT) { |
| return leftPad(str, size, String.valueOf(padChar)); |
| } |
| return padding(pads, padChar).concat(str); |
| } |
| |
| /** |
| * <p>Left pad a String with a specified String.</p> |
| * |
| * <p>Pad to a size of <code>size</code>.</p> |
| * |
| * <pre> |
| * StringUtils.leftPad(null, *, *) = null |
| * StringUtils.leftPad("", 3, "z") = "zzz" |
| * StringUtils.leftPad("bat", 3, "yz") = "bat" |
| * StringUtils.leftPad("bat", 5, "yz") = "yzbat" |
| * StringUtils.leftPad("bat", 8, "yz") = "yzyzybat" |
| * StringUtils.leftPad("bat", 1, "yz") = "bat" |
| * StringUtils.leftPad("bat", -1, "yz") = "bat" |
| * StringUtils.leftPad("bat", 5, null) = " bat" |
| * StringUtils.leftPad("bat", 5, "") = " bat" |
| * </pre> |
| * |
| * @param str the String to pad out, may be null |
| * @param size the size to pad to |
| * @param padStr the String to pad with, null or empty treated as single space |
| * @return left padded String or original String if no padding is necessary, |
| * <code>null</code> if null String input |
| */ |
| public static String leftPad(String str, int size, String padStr) { |
| if (str == null) { |
| return null; |
| } |
| if (isEmpty(padStr)) { |
| padStr = " "; |
| } |
| int padLen = padStr.length(); |
| int strLen = str.length(); |
| int pads = size - strLen; |
| if (pads <= 0) { |
| return str; // returns original String when possible |
| } |
| if (padLen == 1 && pads <= PAD_LIMIT) { |
| return leftPad(str, size, padStr.charAt(0)); |
| } |
| |
| if (pads == padLen) { |
| return padStr.concat(str); |
| } else if (pads < padLen) { |
| return padStr.substring(0, pads).concat(str); |
| } else { |
| char[] padding = new char[pads]; |
| char[] padChars = padStr.toCharArray(); |
| for (int i = 0; i < pads; i++) { |
| padding[i] = padChars[i % padLen]; |
| } |
| return new String(padding).concat(str); |
| } |
| } |
| |
| // Centering |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Centers a String in a larger String of size <code>size</code> |
| * using the space character (' ').<p> |
| * |
| * <p>If the size is less than the String length, the String is returned. |
| * A <code>null</code> String returns <code>null</code>. |
| * A negative size is treated as zero.</p> |
| * |
| * <p>Equivalent to <code>center(str, size, " ")</code>.</p> |
| * |
| * <pre> |
| * StringUtils.center(null, *) = null |
| * StringUtils.center("", 4) = " " |
| * StringUtils.center("ab", -1) = "ab" |
| * StringUtils.center("ab", 4) = " ab " |
| * StringUtils.center("abcd", 2) = "abcd" |
| * StringUtils.center("a", 4) = " a " |
| * </pre> |
| * |
| * @param str the String to center, may be null |
| * @param size the int size of new String, negative treated as zero |
| * @return centered String, <code>null</code> if null String input |
| */ |
| public static String center(String str, int size) { |
| return center(str, size, ' '); |
| } |
| |
| /** |
| * <p>Centers a String in a larger String of size <code>size</code>. |
| * Uses a supplied character as the value to pad the String with.</p> |
| * |
| * <p>If the size is less than the String length, the String is returned. |
| * A <code>null</code> String returns <code>null</code>. |
| * A negative size is treated as zero.</p> |
| * |
| * <pre> |
| * StringUtils.center(null, *, *) = null |
| * StringUtils.center("", 4, ' ') = " " |
| * StringUtils.center("ab", -1, ' ') = "ab" |
| * StringUtils.center("ab", 4, ' ') = " ab" |
| * StringUtils.center("abcd", 2, ' ') = "abcd" |
| * StringUtils.center("a", 4, ' ') = " a " |
| * StringUtils.center("a", 4, 'y') = "yayy" |
| * </pre> |
| * |
| * @param str the String to center, may be null |
| * @param size the int size of new String, negative treated as zero |
| * @param padChar the character to pad the new String with |
| * @return centered String, <code>null</code> if null String input |
| * @since 2.0 |
| */ |
| public static String center(String str, int size, char padChar) { |
| if (str == null || size <= 0) { |
| return str; |
| } |
| int strLen = str.length(); |
| int pads = size - strLen; |
| if (pads <= 0) { |
| return str; |
| } |
| str = leftPad(str, strLen + pads / 2, padChar); |
| str = rightPad(str, size, padChar); |
| return str; |
| } |
| |
| /** |
| * <p>Centers a String in a larger String of size <code>size</code>. |
| * Uses a supplied String as the value to pad the String with.</p> |
| * |
| * <p>If the size is less than the String length, the String is returned. |
| * A <code>null</code> String returns <code>null</code>. |
| * A negative size is treated as zero.</p> |
| * |
| * <pre> |
| * StringUtils.center(null, *, *) = null |
| * StringUtils.center("", 4, " ") = " " |
| * StringUtils.center("ab", -1, " ") = "ab" |
| * StringUtils.center("ab", 4, " ") = " ab" |
| * StringUtils.center("abcd", 2, " ") = "abcd" |
| * StringUtils.center("a", 4, " ") = " a " |
| * StringUtils.center("a", 4, "yz") = "yayz" |
| * StringUtils.center("abc", 7, null) = " abc " |
| * StringUtils.center("abc", 7, "") = " abc " |
| * </pre> |
| * |
| * @param str the String to center, may be null |
| * @param size the int size of new String, negative treated as zero |
| * @param padStr the String to pad the new String with, must not be null or empty |
| * @return centered String, <code>null</code> if null String input |
| * @throws IllegalArgumentException if padStr is <code>null</code> or empty |
| */ |
| public static String center(String str, int size, String padStr) { |
| if (str == null || size <= 0) { |
| return str; |
| } |
| if (isEmpty(padStr)) { |
| padStr = " "; |
| } |
| int strLen = str.length(); |
| int pads = size - strLen; |
| if (pads <= 0) { |
| return str; |
| } |
| str = leftPad(str, strLen + pads / 2, padStr); |
| str = rightPad(str, size, padStr); |
| return str; |
| } |
| |
| // Case conversion |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Converts a String to upper case as per {@link String#toUpperCase()}.</p> |
| * |
| * <p>A <code>null</code> input String returns <code>null</code>.</p> |
| * |
| * <pre> |
| * StringUtils.upperCase(null) = null |
| * StringUtils.upperCase("") = "" |
| * StringUtils.upperCase("aBc") = "ABC" |
| * </pre> |
| * |
| * @param str the String to upper case, may be null |
| * @return the upper cased String, <code>null</code> if null String input |
| */ |
| public static String upperCase(String str) { |
| if (str == null) { |
| return null; |
| } |
| return str.toUpperCase(); |
| } |
| |
| /** |
| * <p>Converts a String to lower case as per {@link String#toLowerCase()}.</p> |
| * |
| * <p>A <code>null</code> input String returns <code>null</code>.</p> |
| * |
| * <pre> |
| * StringUtils.lowerCase(null) = null |
| * StringUtils.lowerCase("") = "" |
| * StringUtils.lowerCase("aBc") = "abc" |
| * </pre> |
| * |
| * @param str the String to lower case, may be null |
| * @return the lower cased String, <code>null</code> if null String input |
| */ |
| public static String lowerCase(String str) { |
| if (str == null) { |
| return null; |
| } |
| return str.toLowerCase(); |
| } |
| |
| /** |
| * <p>Capitalizes a String changing the first letter to title case as |
| * per {@link Character#toTitleCase(char)}. No other letters are changed.</p> |
| * |
| * <p>For a word based algorithm, see {@link WordUtils#capitalize(String)}. |
| * A <code>null</code> input String returns <code>null</code>.</p> |
| * |
| * <pre> |
| * StringUtils.capitalize(null) = null |
| * StringUtils.capitalize("") = "" |
| * StringUtils.capitalize("cat") = "Cat" |
| * StringUtils.capitalize("cAt") = "CAt" |
| * </pre> |
| * |
| * @param str the String to capitalize, may be null |
| * @return the capitalized String, <code>null</code> if null String input |
| * @see WordUtils#capitalize(String) |
| * @see #uncapitalize(String) |
| * @since 2.0 |
| */ |
| public static String capitalize(String str) { |
| int strLen; |
| if (str == null || (strLen = str.length()) == 0) { |
| return str; |
| } |
| return new StringBuffer(strLen) |
| .append(Character.toTitleCase(str.charAt(0))) |
| .append(str.substring(1)) |
| .toString(); |
| } |
| |
| /** |
| * <p>Capitalizes a String changing the first letter to title case as |
| * per {@link Character#toTitleCase(char)}. No other letters are changed.</p> |
| * |
| * @param str the String to capitalize, may be null |
| * @return the capitalized String, <code>null</code> if null String input |
| * @deprecated Use the standardly named {@link #capitalize(String)}. |
| * Method will be removed in Commons Lang 3.0. |
| */ |
| public static String capitalise(String str) { |
| return capitalize(str); |
| } |
| |
| /** |
| * <p>Uncapitalizes a String changing the first letter to title case as |
| * per {@link Character#toLowerCase(char)}. No other letters are changed.</p> |
| * |
| * <p>For a word based algorithm, see {@link WordUtils#uncapitalize(String)}. |
| * A <code>null</code> input String returns <code>null</code>.</p> |
| * |
| * <pre> |
| * StringUtils.uncapitalize(null) = null |
| * StringUtils.uncapitalize("") = "" |
| * StringUtils.uncapitalize("Cat") = "cat" |
| * StringUtils.uncapitalize("CAT") = "cAT" |
| * </pre> |
| * |
| * @param str the String to uncapitalize, may be null |
| * @return the uncapitalized String, <code>null</code> if null String input |
| * @see WordUtils#uncapitalize(String) |
| * @see #capitalize(String) |
| * @since 2.0 |
| */ |
| public static String uncapitalize(String str) { |
| int strLen; |
| if (str == null || (strLen = str.length()) == 0) { |
| return str; |
| } |
| return new StringBuffer(strLen) |
| .append(Character.toLowerCase(str.charAt(0))) |
| .append(str.substring(1)) |
| .toString(); |
| } |
| |
| /** |
| * <p>Uncapitalizes a String changing the first letter to title case as |
| * per {@link Character#toLowerCase(char)}. No other letters are changed.</p> |
| * |
| * @param str the String to uncapitalize, may be null |
| * @return the uncapitalized String, <code>null</code> if null String input |
| * @deprecated Use the standardly named {@link #uncapitalize(String)}. |
| * Method will be removed in Commons Lang 3.0. |
| */ |
| public static String uncapitalise(String str) { |
| return uncapitalize(str); |
| } |
| |
| /** |
| * <p>Swaps the case of a String changing upper and title case to |
| * lower case, and lower case to upper case.</p> |
| * |
| * <ul> |
| * <li>Upper case character converts to Lower case</li> |
| * <li>Title case character converts to Lower case</li> |
| * <li>Lower case character converts to Upper case</li> |
| * </ul> |
| * |
| * <p>For a word based algorithm, see {@link WordUtils#swapCase(String)}. |
| * A <code>null</code> input String returns <code>null</code>.</p> |
| * |
| * <pre> |
| * StringUtils.swapCase(null) = null |
| * StringUtils.swapCase("") = "" |
| * StringUtils.swapCase("The dog has a BONE") = "tHE DOG HAS A bone" |
| * </pre> |
| * |
| * <p>NOTE: This method changed in Lang version 2.0. |
| * It no longer performs a word based algorithm. |
| * If you only use ASCII, you will notice no change. |
| * That functionality is available in WordUtils.</p> |
| * |
| * @param str the String to swap case, may be null |
| * @return the changed String, <code>null</code> if null String input |
| */ |
| public static String swapCase(String str) { |
| int strLen; |
| if (str == null || (strLen = str.length()) == 0) { |
| return str; |
| } |
| StringBuffer buffer = new StringBuffer(strLen); |
| |
| char ch = 0; |
| for (int i = 0; i < strLen; i++) { |
| ch = str.charAt(i); |
| if (Character.isUpperCase(ch)) { |
| ch = Character.toLowerCase(ch); |
| } else if (Character.isTitleCase(ch)) { |
| ch = Character.toLowerCase(ch); |
| } else if (Character.isLowerCase(ch)) { |
| ch = Character.toUpperCase(ch); |
| } |
| buffer.append(ch); |
| } |
| return buffer.toString(); |
| } |
| |
| /** |
| * <p>Capitalizes all the whitespace separated words in a String. |
| * Only the first letter of each word is changed.</p> |
| * |
| * <p>Whitespace is defined by {@link Character#isWhitespace(char)}. |
| * A <code>null</code> input String returns <code>null</code>.</p> |
| * |
| * @param str the String to capitalize, may be null |
| * @return capitalized String, <code>null</code> if null String input |
| * @deprecated Use the relocated {@link WordUtils#capitalize(String)}. |
| * Method will be removed in Commons Lang 3.0. |
| */ |
| public static String capitaliseAllWords(String str) { |
| return WordUtils.capitalize(str); |
| } |
| |
| // Count matches |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Counts how many times the substring appears in the larger String.</p> |
| * |
| * <p>A <code>null</code> or empty ("") String input returns <code>0</code>.</p> |
| * |
| * <pre> |
| * StringUtils.countMatches(null, *) = 0 |
| * StringUtils.countMatches("", *) = 0 |
| * StringUtils.countMatches("abba", null) = 0 |
| * StringUtils.countMatches("abba", "") = 0 |
| * StringUtils.countMatches("abba", "a") = 2 |
| * StringUtils.countMatches("abba", "ab") = 1 |
| * StringUtils.countMatches("abba", "xxx") = 0 |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @param sub the substring to count, may be null |
| * @return the number of occurrences, 0 if either String is <code>null</code> |
| */ |
| public static int countMatches(String str, String sub) { |
| if (isEmpty(str) || isEmpty(sub)) { |
| return 0; |
| } |
| int count = 0; |
| int idx = 0; |
| while ((idx = str.indexOf(sub, idx)) != -1) { |
| count++; |
| idx += sub.length(); |
| } |
| return count; |
| } |
| |
| // Character Tests |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Checks if the String contains only unicode letters.</p> |
| * |
| * <p><code>null</code> will return <code>false</code>. |
| * An empty String ("") will return <code>true</code>.</p> |
| * |
| * <pre> |
| * StringUtils.isAlpha(null) = false |
| * StringUtils.isAlpha("") = true |
| * StringUtils.isAlpha(" ") = false |
| * StringUtils.isAlpha("abc") = true |
| * StringUtils.isAlpha("ab2c") = false |
| * StringUtils.isAlpha("ab-c") = false |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @return <code>true</code> if only contains letters, and is non-null |
| */ |
| public static boolean isAlpha(String str) { |
| if (str == null) { |
| return false; |
| } |
| int sz = str.length(); |
| for (int i = 0; i < sz; i++) { |
| if (Character.isLetter(str.charAt(i)) == false) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| /** |
| * <p>Checks if the String contains only unicode letters and |
| * space (' ').</p> |
| * |
| * <p><code>null</code> will return <code>false</code> |
| * An empty String ("") will return <code>true</code>.</p> |
| * |
| * <pre> |
| * StringUtils.isAlphaSpace(null) = false |
| * StringUtils.isAlphaSpace("") = true |
| * StringUtils.isAlphaSpace(" ") = true |
| * StringUtils.isAlphaSpace("abc") = true |
| * StringUtils.isAlphaSpace("ab c") = true |
| * StringUtils.isAlphaSpace("ab2c") = false |
| * StringUtils.isAlphaSpace("ab-c") = false |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @return <code>true</code> if only contains letters and space, |
| * and is non-null |
| */ |
| public static boolean isAlphaSpace(String str) { |
| if (str == null) { |
| return false; |
| } |
| int sz = str.length(); |
| for (int i = 0; i < sz; i++) { |
| if ((Character.isLetter(str.charAt(i)) == false) && (str.charAt(i) != ' ')) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| /** |
| * <p>Checks if the String contains only unicode letters or digits.</p> |
| * |
| * <p><code>null</code> will return <code>false</code>. |
| * An empty String ("") will return <code>true</code>.</p> |
| * |
| * <pre> |
| * StringUtils.isAlphanumeric(null) = false |
| * StringUtils.isAlphanumeric("") = true |
| * StringUtils.isAlphanumeric(" ") = false |
| * StringUtils.isAlphanumeric("abc") = true |
| * StringUtils.isAlphanumeric("ab c") = false |
| * StringUtils.isAlphanumeric("ab2c") = true |
| * StringUtils.isAlphanumeric("ab-c") = false |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @return <code>true</code> if only contains letters or digits, |
| * and is non-null |
| */ |
| public static boolean isAlphanumeric(String str) { |
| if (str == null) { |
| return false; |
| } |
| int sz = str.length(); |
| for (int i = 0; i < sz; i++) { |
| if (Character.isLetterOrDigit(str.charAt(i)) == false) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| /** |
| * <p>Checks if the String contains only unicode letters, digits |
| * or space (<code>' '</code>).</p> |
| * |
| * <p><code>null</code> will return <code>false</code>. |
| * An empty String ("") will return <code>true</code>.</p> |
| * |
| * <pre> |
| * StringUtils.isAlphanumeric(null) = false |
| * StringUtils.isAlphanumeric("") = true |
| * StringUtils.isAlphanumeric(" ") = true |
| * StringUtils.isAlphanumeric("abc") = true |
| * StringUtils.isAlphanumeric("ab c") = true |
| * StringUtils.isAlphanumeric("ab2c") = true |
| * StringUtils.isAlphanumeric("ab-c") = false |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @return <code>true</code> if only contains letters, digits or space, |
| * and is non-null |
| */ |
| public static boolean isAlphanumericSpace(String str) { |
| if (str == null) { |
| return false; |
| } |
| int sz = str.length(); |
| for (int i = 0; i < sz; i++) { |
| if ((Character.isLetterOrDigit(str.charAt(i)) == false) && (str.charAt(i) != ' ')) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| /** |
| * <p>Checks if the string contains only ASCII printable characters.</p> |
| * |
| * <p><code>null</code> will return <code>false</code>. |
| * An empty String ("") will return <code>true</code>.</p> |
| * |
| * <pre> |
| * StringUtils.isAsciiPrintable(null) = false |
| * StringUtils.isAsciiPrintable("") = true |
| * StringUtils.isAsciiPrintable(" ") = true |
| * StringUtils.isAsciiPrintable("Ceki") = true |
| * StringUtils.isAsciiPrintable("ab2c") = true |
| * StringUtils.isAsciiPrintable("!ab-c~") = true |
| * StringUtils.isAsciiPrintable("\u0020") = true |
| * StringUtils.isAsciiPrintable("\u0021") = true |
| * StringUtils.isAsciiPrintable("\u007e") = true |
| * StringUtils.isAsciiPrintable("\u007f") = false |
| * StringUtils.isAsciiPrintable("Ceki G\u00fclc\u00fc") = false |
| * </pre> |
| * |
| * @param str the string to check, may be null |
| * @return <code>true</code> if every character is in the range |
| * 32 thru 126 |
| * @since 2.1 |
| */ |
| public static boolean isAsciiPrintable(String str) { |
| if (str == null) { |
| return false; |
| } |
| int sz = str.length(); |
| for (int i = 0; i < sz; i++) { |
| if (CharUtils.isAsciiPrintable(str.charAt(i)) == false) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| /** |
| * <p>Checks if the String contains only unicode digits. |
| * A decimal point is not a unicode digit and returns false.</p> |
| * |
| * <p><code>null</code> will return <code>false</code>. |
| * An empty String ("") will return <code>true</code>.</p> |
| * |
| * <pre> |
| * StringUtils.isNumeric(null) = false |
| * StringUtils.isNumeric("") = true |
| * StringUtils.isNumeric(" ") = false |
| * StringUtils.isNumeric("123") = true |
| * StringUtils.isNumeric("12 3") = false |
| * StringUtils.isNumeric("ab2c") = false |
| * StringUtils.isNumeric("12-3") = false |
| * StringUtils.isNumeric("12.3") = false |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @return <code>true</code> if only contains digits, and is non-null |
| */ |
| public static boolean isNumeric(String str) { |
| if (str == null) { |
| return false; |
| } |
| int sz = str.length(); |
| for (int i = 0; i < sz; i++) { |
| if (Character.isDigit(str.charAt(i)) == false) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| /** |
| * <p>Checks if the String contains only unicode digits or space |
| * (<code>' '</code>). |
| * A decimal point is not a unicode digit and returns false.</p> |
| * |
| * <p><code>null</code> will return <code>false</code>. |
| * An empty String ("") will return <code>true</code>.</p> |
| * |
| * <pre> |
| * StringUtils.isNumeric(null) = false |
| * StringUtils.isNumeric("") = true |
| * StringUtils.isNumeric(" ") = true |
| * StringUtils.isNumeric("123") = true |
| * StringUtils.isNumeric("12 3") = true |
| * StringUtils.isNumeric("ab2c") = false |
| * StringUtils.isNumeric("12-3") = false |
| * StringUtils.isNumeric("12.3") = false |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @return <code>true</code> if only contains digits or space, |
| * and is non-null |
| */ |
| public static boolean isNumericSpace(String str) { |
| if (str == null) { |
| return false; |
| } |
| int sz = str.length(); |
| for (int i = 0; i < sz; i++) { |
| if ((Character.isDigit(str.charAt(i)) == false) && (str.charAt(i) != ' ')) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| /** |
| * <p>Checks if the String contains only whitespace.</p> |
| * |
| * <p><code>null</code> will return <code>false</code>. |
| * An empty String ("") will return <code>true</code>.</p> |
| * |
| * <pre> |
| * StringUtils.isWhitespace(null) = false |
| * StringUtils.isWhitespace("") = true |
| * StringUtils.isWhitespace(" ") = true |
| * StringUtils.isWhitespace("abc") = false |
| * StringUtils.isWhitespace("ab2c") = false |
| * StringUtils.isWhitespace("ab-c") = false |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @return <code>true</code> if only contains whitespace, and is non-null |
| * @since 2.0 |
| */ |
| public static boolean isWhitespace(String str) { |
| if (str == null) { |
| return false; |
| } |
| int sz = str.length(); |
| for (int i = 0; i < sz; i++) { |
| if ((Character.isWhitespace(str.charAt(i)) == false)) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| // Defaults |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Returns either the passed in String, |
| * or if the String is <code>null</code>, an empty String ("").</p> |
| * |
| * <pre> |
| * StringUtils.defaultString(null) = "" |
| * StringUtils.defaultString("") = "" |
| * StringUtils.defaultString("bat") = "bat" |
| * </pre> |
| * |
| * @see ObjectUtils#toString(Object) |
| * @see String#valueOf(Object) |
| * @param str the String to check, may be null |
| * @return the passed in String, or the empty String if it |
| * was <code>null</code> |
| */ |
| public static String defaultString(String str) { |
| return str == null ? EMPTY : str; |
| } |
| |
| /** |
| * <p>Returns either the passed in String, or if the String is |
| * <code>null</code>, the value of <code>defaultStr</code>.</p> |
| * |
| * <pre> |
| * StringUtils.defaultString(null, "NULL") = "NULL" |
| * StringUtils.defaultString("", "NULL") = "" |
| * StringUtils.defaultString("bat", "NULL") = "bat" |
| * </pre> |
| * |
| * @see ObjectUtils#toString(Object,String) |
| * @see String#valueOf(Object) |
| * @param str the String to check, may be null |
| * @param defaultStr the default String to return |
| * if the input is <code>null</code>, may be null |
| * @return the passed in String, or the default if it was <code>null</code> |
| */ |
| public static String defaultString(String str, String defaultStr) { |
| return str == null ? defaultStr : str; |
| } |
| |
| /** |
| * <p>Returns either the passed in String, or if the String is |
| * empty or <code>null</code>, the value of <code>defaultStr</code>.</p> |
| * |
| * <pre> |
| * StringUtils.defaultIfEmpty(null, "NULL") = "NULL" |
| * StringUtils.defaultIfEmpty("", "NULL") = "NULL" |
| * StringUtils.defaultIfEmpty("bat", "NULL") = "bat" |
| * </pre> |
| * |
| * @see StringUtils#defaultString(String, String) |
| * @param str the String to check, may be null |
| * @param defaultStr the default String to return |
| * if the input is empty ("") or <code>null</code>, may be null |
| * @return the passed in String, or the default |
| */ |
| public static String defaultIfEmpty(String str, String defaultStr) { |
| return StringUtils.isEmpty(str) ? defaultStr : str; |
| } |
| |
| // Reversing |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Reverses a String as per {@link StringBuffer#reverse()}.</p> |
| * |
| * <p>A <code>null</code> String returns <code>null</code>.</p> |
| * |
| * <pre> |
| * StringUtils.reverse(null) = null |
| * StringUtils.reverse("") = "" |
| * StringUtils.reverse("bat") = "tab" |
| * </pre> |
| * |
| * @param str the String to reverse, may be null |
| * @return the reversed String, <code>null</code> if null String input |
| */ |
| public static String reverse(String str) { |
| if (str == null) { |
| return null; |
| } |
| return new StringBuffer(str).reverse().toString(); |
| } |
| |
| /** |
| * <p>Reverses a String that is delimited by a specific character.</p> |
| * |
| * <p>The Strings between the delimiters are not reversed. |
| * Thus java.lang.String becomes String.lang.java (if the delimiter |
| * is <code>'.'</code>).</p> |
| * |
| * <pre> |
| * StringUtils.reverseDelimited(null, *) = null |
| * StringUtils.reverseDelimited("", *) = "" |
| * StringUtils.reverseDelimited("a.b.c", 'x') = "a.b.c" |
| * StringUtils.reverseDelimited("a.b.c", ".") = "c.b.a" |
| * </pre> |
| * |
| * @param str the String to reverse, may be null |
| * @param separatorChar the separator character to use |
| * @return the reversed String, <code>null</code> if null String input |
| * @since 2.0 |
| */ |
| public static String reverseDelimited(String str, char separatorChar) { |
| if (str == null) { |
| return null; |
| } |
| // could implement manually, but simple way is to reuse other, |
| // probably slower, methods. |
| String[] strs = split(str, separatorChar); |
| ArrayUtils.reverse(strs); |
| return join(strs, separatorChar); |
| } |
| |
| /** |
| * <p>Reverses a String that is delimited by a specific character.</p> |
| * |
| * <p>The Strings between the delimiters are not reversed. |
| * Thus java.lang.String becomes String.lang.java (if the delimiter |
| * is <code>"."</code>).</p> |
| * |
| * <pre> |
| * StringUtils.reverseDelimitedString(null, *) = null |
| * StringUtils.reverseDelimitedString("",*) = "" |
| * StringUtils.reverseDelimitedString("a.b.c", null) = "a.b.c" |
| * StringUtils.reverseDelimitedString("a.b.c", ".") = "c.b.a" |
| * </pre> |
| * |
| * @param str the String to reverse, may be null |
| * @param separatorChars the separator characters to use, null treated as whitespace |
| * @return the reversed String, <code>null</code> if null String input |
| * @deprecated Use {@link #reverseDelimited(String, char)} instead. |
| * This method is broken as the join doesn't know which char to use. |
| * Method will be removed in Commons Lang 3.0. |
| * |
| */ |
| public static String reverseDelimitedString(String str, String separatorChars) { |
| if (str == null) { |
| return null; |
| } |
| // could implement manually, but simple way is to reuse other, |
| // probably slower, methods. |
| String[] strs = split(str, separatorChars); |
| ArrayUtils.reverse(strs); |
| if (separatorChars == null) { |
| return join(strs, ' '); |
| } |
| return join(strs, separatorChars); |
| } |
| |
| // Abbreviating |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Abbreviates a String using ellipses. This will turn |
| * "Now is the time for all good men" into "Now is the time for..."</p> |
| * |
| * <p>Specifically: |
| * <ul> |
| * <li>If <code>str</code> is less than <code>maxWidth</code> characters |
| * long, return it.</li> |
| * <li>Else abbreviate it to <code>(substring(str, 0, max-3) + "...")</code>.</li> |
| * <li>If <code>maxWidth</code> is less than <code>4</code>, throw an |
| * <code>IllegalArgumentException</code>.</li> |
| * <li>In no case will it return a String of length greater than |
| * <code>maxWidth</code>.</li> |
| * </ul> |
| * </p> |
| * |
| * <pre> |
| * StringUtils.abbreviate(null, *) = null |
| * StringUtils.abbreviate("", 4) = "" |
| * StringUtils.abbreviate("abcdefg", 6) = "abc..." |
| * StringUtils.abbreviate("abcdefg", 7) = "abcdefg" |
| * StringUtils.abbreviate("abcdefg", 8) = "abcdefg" |
| * StringUtils.abbreviate("abcdefg", 4) = "a..." |
| * StringUtils.abbreviate("abcdefg", 3) = IllegalArgumentException |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @param maxWidth maximum length of result String, must be at least 4 |
| * @return abbreviated String, <code>null</code> if null String input |
| * @throws IllegalArgumentException if the width is too small |
| * @since 2.0 |
| */ |
| public static String abbreviate(String str, int maxWidth) { |
| return abbreviate(str, 0, maxWidth); |
| } |
| |
| /** |
| * <p>Abbreviates a String using ellipses. This will turn |
| * "Now is the time for all good men" into "...is the time for..."</p> |
| * |
| * <p>Works like <code>abbreviate(String, int)</code>, but allows you to specify |
| * a "left edge" offset. Note that this left edge is not necessarily going to |
| * be the leftmost character in the result, or the first character following the |
| * ellipses, but it will appear somewhere in the result. |
| * |
| * <p>In no case will it return a String of length greater than |
| * <code>maxWidth</code>.</p> |
| * |
| * <pre> |
| * StringUtils.abbreviate(null, *, *) = null |
| * StringUtils.abbreviate("", 0, 4) = "" |
| * StringUtils.abbreviate("abcdefghijklmno", -1, 10) = "abcdefg..." |
| * StringUtils.abbreviate("abcdefghijklmno", 0, 10) = "abcdefg..." |
| * StringUtils.abbreviate("abcdefghijklmno", 1, 10) = "abcdefg..." |
| * StringUtils.abbreviate("abcdefghijklmno", 4, 10) = "abcdefg..." |
| * StringUtils.abbreviate("abcdefghijklmno", 5, 10) = "...fghi..." |
| * StringUtils.abbreviate("abcdefghijklmno", 6, 10) = "...ghij..." |
| * StringUtils.abbreviate("abcdefghijklmno", 8, 10) = "...ijklmno" |
| * StringUtils.abbreviate("abcdefghijklmno", 10, 10) = "...ijklmno" |
| * StringUtils.abbreviate("abcdefghijklmno", 12, 10) = "...ijklmno" |
| * StringUtils.abbreviate("abcdefghij", 0, 3) = IllegalArgumentException |
| * StringUtils.abbreviate("abcdefghij", 5, 6) = IllegalArgumentException |
| * </pre> |
| * |
| * @param str the String to check, may be null |
| * @param offset left edge of source String |
| * @param maxWidth maximum length of result String, must be at least 4 |
| * @return abbreviated String, <code>null</code> if null String input |
| * @throws IllegalArgumentException if the width is too small |
| * @since 2.0 |
| */ |
| public static String abbreviate(String str, int offset, int maxWidth) { |
| if (str == null) { |
| return null; |
| } |
| if (maxWidth < 4) { |
| throw new IllegalArgumentException("Minimum abbreviation width is 4"); |
| } |
| if (str.length() <= maxWidth) { |
| return str; |
| } |
| if (offset > str.length()) { |
| offset = str.length(); |
| } |
| if ((str.length() - offset) < (maxWidth - 3)) { |
| offset = str.length() - (maxWidth - 3); |
| } |
| if (offset <= 4) { |
| return str.substring(0, maxWidth - 3) + "..."; |
| } |
| if (maxWidth < 7) { |
| throw new IllegalArgumentException("Minimum abbreviation width with offset is 7"); |
| } |
| if ((offset + (maxWidth - 3)) < str.length()) { |
| return "..." + abbreviate(str.substring(offset), maxWidth - 3); |
| } |
| return "..." + str.substring(str.length() - (maxWidth - 3)); |
| } |
| |
| // Difference |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Compares two Strings, and returns the portion where they differ. |
| * (More precisely, return the remainder of the second String, |
| * starting from where it's different from the first.)</p> |
| * |
| * <p>For example, |
| * <code>difference("i am a machine", "i am a robot") -> "robot"</code>.</p> |
| * |
| * <pre> |
| * StringUtils.difference(null, null) = null |
| * StringUtils.difference("", "") = "" |
| * StringUtils.difference("", "abc") = "abc" |
| * StringUtils.difference("abc", "") = "" |
| * StringUtils.difference("abc", "abc") = "" |
| * StringUtils.difference("ab", "abxyz") = "xyz" |
| * StringUtils.difference("abcde", "abxyz") = "xyz" |
| * StringUtils.difference("abcde", "xyz") = "xyz" |
| * </pre> |
| * |
| * @param str1 the first String, may be null |
| * @param str2 the second String, may be null |
| * @return the portion of str2 where it differs from str1; returns the |
| * empty String if they are equal |
| * @since 2.0 |
| */ |
| public static String difference(String str1, String str2) { |
| if (str1 == null) { |
| return str2; |
| } |
| if (str2 == null) { |
| return str1; |
| } |
| int at = indexOfDifference(str1, str2); |
| if (at == -1) { |
| return EMPTY; |
| } |
| return str2.substring(at); |
| } |
| |
| /** |
| * <p>Compares two Strings, and returns the index at which the |
| * Strings begin to differ.</p> |
| * |
| * <p>For example, |
| * <code>indexOfDifference("i am a machine", "i am a robot") -> 7</code></p> |
| * |
| * <pre> |
| * StringUtils.indexOfDifference(null, null) = -1 |
| * StringUtils.indexOfDifference("", "") = -1 |
| * StringUtils.indexOfDifference("", "abc") = 0 |
| * StringUtils.indexOfDifference("abc", "") = 0 |
| * StringUtils.indexOfDifference("abc", "abc") = -1 |
| * StringUtils.indexOfDifference("ab", "abxyz") = 2 |
| * StringUtils.indexOfDifference("abcde", "abxyz") = 2 |
| * StringUtils.indexOfDifference("abcde", "xyz") = 0 |
| * </pre> |
| * |
| * @param str1 the first String, may be null |
| * @param str2 the second String, may be null |
| * @return the index where str2 and str1 begin to differ; -1 if they are equal |
| * @since 2.0 |
| */ |
| public static int indexOfDifference(String str1, String str2) { |
| if (str1 == str2) { |
| return -1; |
| } |
| if (str1 == null || str2 == null) { |
| return 0; |
| } |
| int i; |
| for (i = 0; i < str1.length() && i < str2.length(); ++i) { |
| if (str1.charAt(i) != str2.charAt(i)) { |
| break; |
| } |
| } |
| if (i < str2.length() || i < str1.length()) { |
| return i; |
| } |
| return -1; |
| } |
| |
| // Misc |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Find the Levenshtein distance between two Strings.</p> |
| * |
| * <p>This is the number of changes needed to change one String into |
| * another, where each change is a single character modification (deletion, |
| * insertion or substitution).</p> |
| * |
| * <p>The previous implementation of the Levenshtein distance algorithm |
| * was from <a href="http://www.merriampark.com/ld.htm">http://www.merriampark.com/ld.htm</a></p> |
| * |
| * <p>Chas Emerick has written an implementation in Java, which avoids an OutOfMemoryError |
| * which can occur when my Java implementation is used with very large strings.<br> |
| * This implementation of the Levenshtein distance algorithm |
| * is from <a href="http://www.merriampark.com/ldjava.htm">http://www.merriampark.com/ldjava.htm</a></p> |
| * |
| * <pre> |
| * StringUtils.getLevenshteinDistance(null, *) = IllegalArgumentException |
| * StringUtils.getLevenshteinDistance(*, null) = IllegalArgumentException |
| * StringUtils.getLevenshteinDistance("","") = 0 |
| * StringUtils.getLevenshteinDistance("","a") = 1 |
| * StringUtils.getLevenshteinDistance("aaapppp", "") = 7 |
| * StringUtils.getLevenshteinDistance("frog", "fog") = 1 |
| * StringUtils.getLevenshteinDistance("fly", "ant") = 3 |
| * StringUtils.getLevenshteinDistance("elephant", "hippo") = 7 |
| * StringUtils.getLevenshteinDistance("hippo", "elephant") = 7 |
| * StringUtils.getLevenshteinDistance("hippo", "zzzzzzzz") = 8 |
| * StringUtils.getLevenshteinDistance("hello", "hallo") = 1 |
| * </pre> |
| * |
| * @param s the first String, must not be null |
| * @param t the second String, must not be null |
| * @return result distance |
| * @throws IllegalArgumentException if either String input <code>null</code> |
| */ |
| public static int getLevenshteinDistance(String s, String t) { |
| if (s == null || t == null) { |
| throw new IllegalArgumentException("Strings must not be null"); |
| } |
| |
| /* |
| The difference between this impl. and the previous is that, rather |
| than creating and retaining a matrix of size s.length()+1 by t.length()+1, |
| we maintain two single-dimensional arrays of length s.length()+1. The first, d, |
| is the 'current working' distance array that maintains the newest distance cost |
| counts as we iterate through the characters of String s. Each time we increment |
| the index of String t we are comparing, d is copied to p, the second int[]. Doing so |
| allows us to retain the previous cost counts as required by the algorithm (taking |
| the minimum of the cost count to the left, up one, and diagonally up and to the left |
| of the current cost count being calculated). (Note that the arrays aren't really |
| copied anymore, just switched...this is clearly much better than cloning an array |
| or doing a System.arraycopy() each time through the outer loop.) |
| |
| Effectively, the difference between the two implementations is this one does not |
| cause an out of memory condition when calculating the LD over two very large strings. |
| */ |
| |
| int n = s.length(); // length of s |
| int m = t.length(); // length of t |
| |
| if (n == 0) { |
| return m; |
| } else if (m == 0) { |
| return n; |
| } |
| |
| int p[] = new int[n+1]; //'previous' cost array, horizontally |
| int d[] = new int[n+1]; // cost array, horizontally |
| int _d[]; //placeholder to assist in swapping p and d |
| |
| // indexes into strings s and t |
| int i; // iterates through s |
| int j; // iterates through t |
| |
| char t_j; // jth character of t |
| |
| int cost; // cost |
| |
| for (i = 0; i<=n; i++) { |
| p[i] = i; |
| } |
| |
| for (j = 1; j<=m; j++) { |
| t_j = t.charAt(j-1); |
| d[0] = j; |
| |
| for (i=1; i<=n; i++) { |
| cost = s.charAt(i-1)==t_j ? 0 : 1; |
| // minimum of cell to the left+1, to the top+1, diagonally left and up +cost |
| d[i] = Math.min(Math.min(d[i-1]+1, p[i]+1), p[i-1]+cost); |
| } |
| |
| // copy current distance counts to 'previous row' distance counts |
| _d = p; |
| p = d; |
| d = _d; |
| } |
| |
| // our last action in the above loop was to switch d and p, so p now |
| // actually has the most recent cost counts |
| return p[n]; |
| } |
| |
| /** |
| * <p>Gets the minimum of three <code>int</code> values.</p> |
| * |
| * @param a value 1 |
| * @param b value 2 |
| * @param c value 3 |
| * @return the smallest of the values |
| */ |
| /* |
| private static int min(int a, int b, int c) { |
| // Method copied from NumberUtils to avoid dependency on subpackage |
| if (b < a) { |
| a = b; |
| } |
| if (c < a) { |
| a = c; |
| } |
| return a; |
| } |
| */ |
| |
| } |