| /* |
| * 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.codec.binary; |
| |
| import java.io.UnsupportedEncodingException; |
| import java.nio.ByteBuffer; |
| import java.nio.charset.Charset; |
| import java.nio.charset.StandardCharsets; |
| |
| import org.apache.commons.codec.CharEncoding; |
| |
| /** |
| * Converts String to and from bytes using the encodings required by the Java specification. These encodings are |
| * specified in <a href="http://download.oracle.com/javase/7/docs/api/java/nio/charset/Charset.html"> |
| * Standard charsets</a>. |
| * |
| * <p>This class is immutable and thread-safe.</p> |
| * |
| * @see CharEncoding |
| * @see <a href="http://download.oracle.com/javase/7/docs/api/java/nio/charset/Charset.html">Standard charsets</a> |
| * @since 1.4 |
| */ |
| public class StringUtils { |
| |
| /** |
| * <p> |
| * Compares two CharSequences, returning {@code true} if they represent equal sequences of characters. |
| * </p> |
| * |
| * <p> |
| * {@code null}s are handled without exceptions. Two {@code null} 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> |
| * |
| * <p> |
| * Copied from Apache Commons Lang r1583482 on April 10, 2014 (day of 3.3.2 release). |
| * </p> |
| * |
| * @see Object#equals(Object) |
| * @param cs1 |
| * the first CharSequence, may be {@code null} |
| * @param cs2 |
| * the second CharSequence, may be {@code null} |
| * @return {@code true} if the CharSequences are equal (case-sensitive), or both {@code null} |
| * @since 1.10 |
| */ |
| public static boolean equals(final CharSequence cs1, final CharSequence cs2) { |
| if (cs1 == cs2) { |
| return true; |
| } |
| if (cs1 == null || cs2 == null) { |
| return false; |
| } |
| if (cs1 instanceof String && cs2 instanceof String) { |
| return cs1.equals(cs2); |
| } |
| return cs1.length() == cs2.length() && CharSequenceUtils.regionMatches(cs1, false, 0, cs2, 0, cs1.length()); |
| } |
| |
| /** |
| * Calls {@link String#getBytes(Charset)} |
| * |
| * @param string |
| * The string to encode (if null, return null). |
| * @param charset |
| * The {@link Charset} to encode the {@code String} |
| * @return the encoded bytes |
| */ |
| private static ByteBuffer getByteBuffer(final String string, final Charset charset) { |
| if (string == null) { |
| return null; |
| } |
| return ByteBuffer.wrap(string.getBytes(charset)); |
| } |
| |
| /** |
| * Encodes the given string into a byte buffer using the UTF-8 charset, storing the result into a new byte |
| * array. |
| * |
| * @param string |
| * the String to encode, may be {@code null} |
| * @return encoded bytes, or {@code null} if the input string was {@code null} |
| * @throws NullPointerException |
| * Thrown if {@link StandardCharsets#UTF_8} is not initialized, which should never happen since it is |
| * required by the Java platform specification. |
| * @see <a href="http://download.oracle.com/javase/7/docs/api/java/nio/charset/Charset.html">Standard charsets</a> |
| * @see #getBytesUnchecked(String, String) |
| * @since 1.11 |
| */ |
| public static ByteBuffer getByteBufferUtf8(final String string) { |
| return getByteBuffer(string, StandardCharsets.UTF_8); |
| } |
| |
| /** |
| * Calls {@link String#getBytes(Charset)} |
| * |
| * @param string |
| * The string to encode (if null, return null). |
| * @param charset |
| * The {@link Charset} to encode the {@code String} |
| * @return the encoded bytes |
| */ |
| private static byte[] getBytes(final String string, final Charset charset) { |
| if (string == null) { |
| return null; |
| } |
| return string.getBytes(charset); |
| } |
| |
| /** |
| * Encodes the given string into a sequence of bytes using the ISO-8859-1 charset, storing the result into a new |
| * byte array. |
| * |
| * @param string |
| * the String to encode, may be {@code null} |
| * @return encoded bytes, or {@code null} if the input string was {@code null} |
| * @throws NullPointerException |
| * Thrown if {@link StandardCharsets#ISO_8859_1} is not initialized, which should never happen |
| * since it is required by the Java platform specification. |
| * @since As of 1.7, throws {@link NullPointerException} instead of UnsupportedEncodingException |
| * @see <a href="http://download.oracle.com/javase/7/docs/api/java/nio/charset/Charset.html">Standard charsets</a> |
| * @see #getBytesUnchecked(String, String) |
| */ |
| public static byte[] getBytesIso8859_1(final String string) { |
| return getBytes(string, StandardCharsets.ISO_8859_1); |
| } |
| |
| |
| /** |
| * Encodes the given string into a sequence of bytes using the named charset, storing the result into a new byte |
| * array. |
| * <p> |
| * This method catches {@link UnsupportedEncodingException} and rethrows it as {@link IllegalStateException}, which |
| * should never happen for a required charset name. Use this method when the encoding is required to be in the JRE. |
| * </p> |
| * |
| * @param string |
| * the String to encode, may be {@code null} |
| * @param charsetName |
| * The name of a required {@link java.nio.charset.Charset} |
| * @return encoded bytes, or {@code null} if the input string was {@code null} |
| * @throws IllegalStateException |
| * Thrown when a {@link UnsupportedEncodingException} is caught, which should never happen for a |
| * required charset name. |
| * @see CharEncoding |
| * @see String#getBytes(String) |
| */ |
| public static byte[] getBytesUnchecked(final String string, final String charsetName) { |
| if (string == null) { |
| return null; |
| } |
| try { |
| return string.getBytes(charsetName); |
| } catch (final UnsupportedEncodingException e) { |
| throw StringUtils.newIllegalStateException(charsetName, e); |
| } |
| } |
| |
| /** |
| * Encodes the given string into a sequence of bytes using the US-ASCII charset, storing the result into a new byte |
| * array. |
| * |
| * @param string |
| * the String to encode, may be {@code null} |
| * @return encoded bytes, or {@code null} if the input string was {@code null} |
| * @throws NullPointerException |
| * Thrown if {@link StandardCharsets#US_ASCII} is not initialized, which should never happen since it is |
| * required by the Java platform specification. |
| * @since As of 1.7, throws {@link NullPointerException} instead of UnsupportedEncodingException |
| * @see <a href="http://download.oracle.com/javase/7/docs/api/java/nio/charset/Charset.html">Standard charsets</a> |
| * @see #getBytesUnchecked(String, String) |
| */ |
| public static byte[] getBytesUsAscii(final String string) { |
| return getBytes(string, StandardCharsets.US_ASCII); |
| } |
| |
| /** |
| * Encodes the given string into a sequence of bytes using the UTF-16 charset, storing the result into a new byte |
| * array. |
| * |
| * @param string |
| * the String to encode, may be {@code null} |
| * @return encoded bytes, or {@code null} if the input string was {@code null} |
| * @throws NullPointerException |
| * Thrown if {@link StandardCharsets#UTF_16} is not initialized, which should never happen since it is |
| * required by the Java platform specification. |
| * @since As of 1.7, throws {@link NullPointerException} instead of UnsupportedEncodingException |
| * @see <a href="http://download.oracle.com/javase/7/docs/api/java/nio/charset/Charset.html">Standard charsets</a> |
| * @see #getBytesUnchecked(String, String) |
| */ |
| public static byte[] getBytesUtf16(final String string) { |
| return getBytes(string, StandardCharsets.UTF_16); |
| } |
| |
| /** |
| * Encodes the given string into a sequence of bytes using the UTF-16BE charset, storing the result into a new byte |
| * array. |
| * |
| * @param string |
| * the String to encode, may be {@code null} |
| * @return encoded bytes, or {@code null} if the input string was {@code null} |
| * @throws NullPointerException |
| * Thrown if {@link StandardCharsets#UTF_16BE} is not initialized, which should never happen since it is |
| * required by the Java platform specification. |
| * @since As of 1.7, throws {@link NullPointerException} instead of UnsupportedEncodingException |
| * @see <a href="http://download.oracle.com/javase/7/docs/api/java/nio/charset/Charset.html">Standard charsets</a> |
| * @see #getBytesUnchecked(String, String) |
| */ |
| public static byte[] getBytesUtf16Be(final String string) { |
| return getBytes(string, StandardCharsets.UTF_16BE); |
| } |
| |
| /** |
| * Encodes the given string into a sequence of bytes using the UTF-16LE charset, storing the result into a new byte |
| * array. |
| * |
| * @param string |
| * the String to encode, may be {@code null} |
| * @return encoded bytes, or {@code null} if the input string was {@code null} |
| * @throws NullPointerException |
| * Thrown if {@link StandardCharsets#UTF_16LE} is not initialized, which should never happen since it is |
| * required by the Java platform specification. |
| * @since As of 1.7, throws {@link NullPointerException} instead of UnsupportedEncodingException |
| * @see <a href="http://download.oracle.com/javase/7/docs/api/java/nio/charset/Charset.html">Standard charsets</a> |
| * @see #getBytesUnchecked(String, String) |
| */ |
| public static byte[] getBytesUtf16Le(final String string) { |
| return getBytes(string, StandardCharsets.UTF_16LE); |
| } |
| |
| /** |
| * Encodes the given string into a sequence of bytes using the UTF-8 charset, storing the result into a new byte |
| * array. |
| * |
| * @param string |
| * the String to encode, may be {@code null} |
| * @return encoded bytes, or {@code null} if the input string was {@code null} |
| * @throws NullPointerException |
| * Thrown if {@link StandardCharsets#UTF_8} is not initialized, which should never happen since it is |
| * required by the Java platform specification. |
| * @since As of 1.7, throws {@link NullPointerException} instead of UnsupportedEncodingException |
| * @see <a href="http://download.oracle.com/javase/7/docs/api/java/nio/charset/Charset.html">Standard charsets</a> |
| * @see #getBytesUnchecked(String, String) |
| */ |
| public static byte[] getBytesUtf8(final String string) { |
| return getBytes(string, StandardCharsets.UTF_8); |
| } |
| |
| private static IllegalStateException newIllegalStateException(final String charsetName, |
| final UnsupportedEncodingException e) { |
| return new IllegalStateException(charsetName + ": " + e); |
| } |
| |
| /** |
| * Constructs a new {@code String} by decoding the specified array of bytes using the given charset. |
| * |
| * @param bytes |
| * The bytes to be decoded into characters |
| * @param charset |
| * The {@link Charset} to encode the {@code String}; not {@code null} |
| * @return A new {@code String} decoded from the specified array of bytes using the given charset, |
| * or {@code null} if the input byte array was {@code null}. |
| * @throws NullPointerException |
| * Thrown if charset is {@code null} |
| */ |
| private static String newString(final byte[] bytes, final Charset charset) { |
| return bytes == null ? null : new String(bytes, charset); |
| } |
| |
| /** |
| * Constructs a new {@code String} by decoding the specified array of bytes using the given charset. |
| * <p> |
| * This method catches {@link UnsupportedEncodingException} and re-throws it as {@link IllegalStateException}, which |
| * should never happen for a required charset name. Use this method when the encoding is required to be in the JRE. |
| * </p> |
| * |
| * @param bytes |
| * The bytes to be decoded into characters, may be {@code null} |
| * @param charsetName |
| * The name of a required {@link java.nio.charset.Charset} |
| * @return A new {@code String} decoded from the specified array of bytes using the given charset, |
| * or {@code null} if the input byte array was {@code null}. |
| * @throws IllegalStateException |
| * Thrown when a {@link UnsupportedEncodingException} is caught, which should never happen for a |
| * required charset name. |
| * @see CharEncoding |
| * @see String#String(byte[], String) |
| */ |
| public static String newString(final byte[] bytes, final String charsetName) { |
| if (bytes == null) { |
| return null; |
| } |
| try { |
| return new String(bytes, charsetName); |
| } catch (final UnsupportedEncodingException e) { |
| throw StringUtils.newIllegalStateException(charsetName, e); |
| } |
| } |
| |
| /** |
| * Constructs a new {@code String} by decoding the specified array of bytes using the ISO-8859-1 charset. |
| * |
| * @param bytes |
| * The bytes to be decoded into characters, may be {@code null} |
| * @return A new {@code String} decoded from the specified array of bytes using the ISO-8859-1 charset, or |
| * {@code null} if the input byte array was {@code null}. |
| * @throws NullPointerException |
| * Thrown if {@link StandardCharsets#ISO_8859_1} is not initialized, which should never happen |
| * since it is required by the Java platform specification. |
| * @since As of 1.7, throws {@link NullPointerException} instead of UnsupportedEncodingException |
| */ |
| public static String newStringIso8859_1(final byte[] bytes) { |
| return newString(bytes, StandardCharsets.ISO_8859_1); |
| } |
| |
| /** |
| * Constructs a new {@code String} by decoding the specified array of bytes using the US-ASCII charset. |
| * |
| * @param bytes |
| * The bytes to be decoded into characters |
| * @return A new {@code String} decoded from the specified array of bytes using the US-ASCII charset, |
| * or {@code null} if the input byte array was {@code null}. |
| * @throws NullPointerException |
| * Thrown if {@link StandardCharsets#US_ASCII} is not initialized, which should never happen since it is |
| * required by the Java platform specification. |
| * @since As of 1.7, throws {@link NullPointerException} instead of UnsupportedEncodingException |
| */ |
| public static String newStringUsAscii(final byte[] bytes) { |
| return newString(bytes, StandardCharsets.US_ASCII); |
| } |
| |
| /** |
| * Constructs a new {@code String} by decoding the specified array of bytes using the UTF-16 charset. |
| * |
| * @param bytes |
| * The bytes to be decoded into characters |
| * @return A new {@code String} decoded from the specified array of bytes using the UTF-16 charset |
| * or {@code null} if the input byte array was {@code null}. |
| * @throws NullPointerException |
| * Thrown if {@link StandardCharsets#UTF_16} is not initialized, which should never happen since it is |
| * required by the Java platform specification. |
| * @since As of 1.7, throws {@link NullPointerException} instead of UnsupportedEncodingException |
| */ |
| public static String newStringUtf16(final byte[] bytes) { |
| return newString(bytes, StandardCharsets.UTF_16); |
| } |
| |
| /** |
| * Constructs a new {@code String} by decoding the specified array of bytes using the UTF-16BE charset. |
| * |
| * @param bytes |
| * The bytes to be decoded into characters |
| * @return A new {@code String} decoded from the specified array of bytes using the UTF-16BE charset, |
| * or {@code null} if the input byte array was {@code null}. |
| * @throws NullPointerException |
| * Thrown if {@link StandardCharsets#UTF_16BE} is not initialized, which should never happen since it is |
| * required by the Java platform specification. |
| * @since As of 1.7, throws {@link NullPointerException} instead of UnsupportedEncodingException |
| */ |
| public static String newStringUtf16Be(final byte[] bytes) { |
| return newString(bytes, StandardCharsets.UTF_16BE); |
| } |
| |
| /** |
| * Constructs a new {@code String} by decoding the specified array of bytes using the UTF-16LE charset. |
| * |
| * @param bytes |
| * The bytes to be decoded into characters |
| * @return A new {@code String} decoded from the specified array of bytes using the UTF-16LE charset, |
| * or {@code null} if the input byte array was {@code null}. |
| * @throws NullPointerException |
| * Thrown if {@link StandardCharsets#UTF_16LE} is not initialized, which should never happen since it is |
| * required by the Java platform specification. |
| * @since As of 1.7, throws {@link NullPointerException} instead of UnsupportedEncodingException |
| */ |
| public static String newStringUtf16Le(final byte[] bytes) { |
| return newString(bytes, StandardCharsets.UTF_16LE); |
| } |
| |
| /** |
| * Constructs a new {@code String} by decoding the specified array of bytes using the UTF-8 charset. |
| * |
| * @param bytes |
| * The bytes to be decoded into characters |
| * @return A new {@code String} decoded from the specified array of bytes using the UTF-8 charset, |
| * or {@code null} if the input byte array was {@code null}. |
| * @throws NullPointerException |
| * Thrown if {@link StandardCharsets#UTF_8} is not initialized, which should never happen since it is |
| * required by the Java platform specification. |
| * @since As of 1.7, throws {@link NullPointerException} instead of UnsupportedEncodingException |
| */ |
| public static String newStringUtf8(final byte[] bytes) { |
| return newString(bytes, StandardCharsets.UTF_8); |
| } |
| |
| } |
