| /* |
| * 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.text; |
| |
| import java.util.Formattable; |
| import java.util.Formatter; |
| |
| import static java.util.FormattableFlags.LEFT_JUSTIFY; |
| |
| /** |
| * <p>Provides utilities for working with the {@code Formattable} interface.</p> |
| * |
| * <p>The {@link Formattable} interface provides basic control over formatting |
| * when using a {@code Formatter}. It is primarily concerned with numeric precision |
| * and padding, and is not designed to allow generalised alternate formats.</p> |
| * |
| * @since 1.0 |
| * |
| */ |
| public class FormattableUtils { |
| |
| /** |
| * A format that simply outputs the value as a string. |
| */ |
| private static final String SIMPLEST_FORMAT = "%s"; |
| |
| /** |
| * <p>{@code FormattableUtils} instances should NOT be constructed in |
| * standard programming. Instead, the methods of the class should be invoked |
| * statically.</p> |
| * |
| * <p>This constructor is public to permit tools that require a JavaBean |
| * instance to operate.</p> |
| */ |
| public FormattableUtils() { |
| super(); |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * Get the default formatted representation of the specified |
| * {@code Formattable}. |
| * |
| * @param formattable the instance to convert to a string, not null |
| * @return the resulting string, not null |
| */ |
| public static String toString(final Formattable formattable) { |
| return String.format(SIMPLEST_FORMAT, formattable); |
| } |
| |
| /** |
| * Handles the common {@code Formattable} operations of truncate-pad-append, |
| * with no ellipsis on precision overflow, and padding width underflow with |
| * spaces. |
| * |
| * @param seq the string to handle, not null |
| * @param formatter the destination formatter, not null |
| * @param flags the flags for formatting, see {@code Formattable} |
| * @param width the width of the output, see {@code Formattable} |
| * @param precision the precision of the output, see {@code Formattable} |
| * @return the {@code formatter} instance, not null |
| */ |
| public static Formatter append(final CharSequence seq, final Formatter formatter, final int flags, final int width, |
| final int precision) { |
| return append(seq, formatter, flags, width, precision, ' ', null); |
| } |
| |
| /** |
| * Handles the common {@link Formattable} operations of truncate-pad-append, |
| * with no ellipsis on precision overflow. |
| * |
| * @param seq the string to handle, not null |
| * @param formatter the destination formatter, not null |
| * @param flags the flags for formatting, see {@code Formattable} |
| * @param width the width of the output, see {@code Formattable} |
| * @param precision the precision of the output, see {@code Formattable} |
| * @param padChar the pad character to use |
| * @return the {@code formatter} instance, not null |
| */ |
| public static Formatter append(final CharSequence seq, final Formatter formatter, final int flags, final int width, |
| final int precision, final char padChar) { |
| return append(seq, formatter, flags, width, precision, padChar, null); |
| } |
| |
| /** |
| * Handles the common {@link Formattable} operations of truncate-pad-append, |
| * padding width underflow with spaces. |
| * |
| * @param seq the string to handle, not null |
| * @param formatter the destination formatter, not null |
| * @param flags the flags for formatting, see {@code Formattable} |
| * @param width the width of the output, see {@code Formattable} |
| * @param precision the precision of the output, see {@code Formattable} |
| * @param ellipsis the ellipsis to use when precision dictates truncation, null or |
| * empty causes a hard truncation |
| * @return the {@code formatter} instance, not null |
| */ |
| public static Formatter append(final CharSequence seq, final Formatter formatter, final int flags, final int width, |
| final int precision, final CharSequence ellipsis) { |
| return append(seq, formatter, flags, width, precision, ' ', ellipsis); |
| } |
| |
| /** |
| * Handles the common {@link Formattable} operations of truncate-pad-append. |
| * |
| * @param seq the string to handle, not null |
| * @param formatter the destination formatter, not null |
| * @param flags the flags for formatting, see {@code Formattable} |
| * @param width the width of the output, see {@code Formattable} |
| * @param precision the precision of the output, see {@code Formattable} |
| * @param padChar the pad character to use |
| * @param ellipsis the ellipsis to use when precision dictates truncation, null or |
| * empty causes a hard truncation |
| * @return the {@code formatter} instance, not null |
| */ |
| public static Formatter append(final CharSequence seq, final Formatter formatter, final int flags, final int width, |
| final int precision, final char padChar, final CharSequence ellipsis) { |
| if (!(ellipsis == null || precision < 0 || ellipsis.length() <= precision)) { |
| throw new IllegalArgumentException( |
| String.format("Specified ellipsis '%s' exceeds precision of %s", |
| ellipsis, |
| precision)); |
| } |
| final StringBuilder buf = new StringBuilder(seq); |
| if (precision >= 0 && precision < seq.length()) { |
| final CharSequence _ellipsis; |
| if (ellipsis == null) { |
| _ellipsis = ""; |
| } else { |
| _ellipsis = ellipsis; |
| } |
| buf.replace(precision - _ellipsis.length(), seq.length(), _ellipsis.toString()); |
| } |
| final boolean leftJustify = (flags & LEFT_JUSTIFY) == LEFT_JUSTIFY; |
| for (int i = buf.length(); i < width; i++) { |
| buf.insert(leftJustify ? i : 0, padChar); |
| } |
| formatter.format(buf.toString()); |
| return formatter; |
| } |
| |
| } |