Java tutorial
/* * 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 de.homelab.madgaksha.lotsofbs.util; import java.util.Locale; import org.apache.commons.lang3.StringUtils; import org.apache.commons.lang3.SystemUtils; /** * <p> * Operations on Strings that contain words. * </p> * * <p> * This class tries to handle <code>null</code> input gracefully. An exception * will not be thrown for a <code>null</code> input. Each method documents its * behaviour in more detail. * </p> * * @since 2.0 * @version $Id: WordUtils.java 1586649 2014-04-11 13:28:30Z britter $ */ public class LocaleRootWordUtils { /** * <p> * <code>WordUtils</code> instances should NOT be constructed in standard * programming. Instead, the class should be used as * <code>WordUtils.wrap("foo bar", 20);</code>. * </p> * * <p> * This constructor is public to permit tools that require a JavaBean * instance to operate. * </p> */ public LocaleRootWordUtils() { super(); } // Wrapping // -------------------------------------------------------------------------- /** * <p> * Wraps a single line of text, identifying words by <code>' '</code>. * </p> * * <p> * New lines will be separated by the system property line separator. Very * long words, such as URLs will <i>not</i> be wrapped. * </p> * * <p> * Leading spaces on a new line are stripped. Trailing spaces are not * stripped. * </p> * * <table border="1" summary="Wrap Results"> * <tr> * <th>input</th> * <th>wrapLength</th> * <th>result</th> * </tr> * <tr> * <td>null</td> * <td>*</td> * <td>null</td> * </tr> * <tr> * <td>""</td> * <td>*</td> * <td>""</td> * </tr> * <tr> * <td> * "Here is one line of text that is going to be wrapped after 20 columns." * </td> * <td>20</td> * <td> * "Here is one line of\ntext that is going\nto be wrapped after\n20 columns." * </td> * </tr> * <tr> * <td> * "Click here to jump to the commons website - http://commons.apache.org" * </td> * <td>20</td> * <td> * "Click here to jump\nto the commons\nwebsite -\nhttp://commons.apache.org" * </td> * </tr> * <tr> * <td> * "Click here, http://commons.apache.org, to jump to the commons website" * </td> * <td>20</td> * <td> * "Click here,\nhttp://commons.apache.org,\nto jump to the\ncommons website" * </td> * </tr> * </table> * * (assuming that '\n' is the systems line separator) * * @param str * the String to be word wrapped, may be null * @param wrapLength * the column to wrap the words at, less than 1 is treated as 1 * @return a line with newlines inserted, <code>null</code> if null input */ public static String wrap(final String str, final int wrapLength) { return wrap(str, wrapLength, null, false); } /** * <p> * Wraps a single line of text, identifying words by <code>' '</code>. * </p> * * <p> * Leading spaces on a new line are stripped. Trailing spaces are not * stripped. * </p> * * <table border="1" summary="Wrap Results"> * <tr> * <th>input</th> * <th>wrapLenght</th> * <th>newLineString</th> * <th>wrapLongWords</th> * <th>result</th> * </tr> * <tr> * <td>null</td> * <td>*</td> * <td>*</td> * <td>true/false</td> * <td>null</td> * </tr> * <tr> * <td>""</td> * <td>*</td> * <td>*</td> * <td>true/false</td> * <td>""</td> * </tr> * <tr> * <td> * "Here is one line of text that is going to be wrapped after 20 columns." * </td> * <td>20</td> * <td>"\n"</td> * <td>true/false</td> * <td> * "Here is one line of\ntext that is going\nto be wrapped after\n20 columns." * </td> * </tr> * <tr> * <td> * "Here is one line of text that is going to be wrapped after 20 columns." * </td> * <td>20</td> * <td>"<br />"</td> * <td>true/false</td> * <td> * "Here is one line of<br />text that is going<br />to be wrapped after<br />20 columns." * </td> * </tr> * <tr> * <td> * "Here is one line of text that is going to be wrapped after 20 columns." * </td> * <td>20</td> * <td>null</td> * <td>true/false</td> * <td>"Here is one line of" + systemNewLine + "text that is going" + * systemNewLine + "to be wrapped after" + systemNewLine + "20 columns." * </td> * </tr> * <tr> * <td> * "Click here to jump to the commons website - http://commons.apache.org" * </td> * <td>20</td> * <td>"\n"</td> * <td>false</td> * <td> * "Click here to jump\nto the commons\nwebsite -\nhttp://commons.apache.org" * </td> * </tr> * <tr> * <td> * "Click here to jump to the commons website - http://commons.apache.org" * </td> * <td>20</td> * <td>"\n"</td> * <td>true</td> * <td> * "Click here to jump\nto the commons\nwebsite -\nhttp://commons.apach\ne.org" * </td> * </tr> * </table> * * @param str * the String to be word wrapped, may be null * @param wrapLength * the column to wrap the words at, less than 1 is treated as 1 * @param newLineStr * the string to insert for a new line, <code>null</code> uses * the system property line separator * @param wrapLongWords * true if long words (such as URLs) should be wrapped * @return a line with newlines inserted, <code>null</code> if null input */ public static String wrap(final String str, int wrapLength, String newLineStr, final boolean wrapLongWords) { if (str == null) { return null; } if (newLineStr == null) { newLineStr = SystemUtils.LINE_SEPARATOR; } if (wrapLength < 1) { wrapLength = 1; } final int inputLineLength = str.length(); int offset = 0; final StringBuilder wrappedLine = new StringBuilder(inputLineLength + 32); while (offset < inputLineLength) { if (str.charAt(offset) == ' ') { offset++; continue; } // only last line without leading spaces is left if (inputLineLength - offset <= wrapLength) { break; } int spaceToWrapAt = str.lastIndexOf(' ', wrapLength + offset); if (spaceToWrapAt >= offset) { // normal case wrappedLine.append(str.substring(offset, spaceToWrapAt)); wrappedLine.append(newLineStr); offset = spaceToWrapAt + 1; } else { // really long word or URL if (wrapLongWords) { // wrap really long word one line at a time wrappedLine.append(str.substring(offset, wrapLength + offset)); wrappedLine.append(newLineStr); offset += wrapLength; } else { // do not wrap really long word, just extend beyond limit spaceToWrapAt = str.indexOf(' ', wrapLength + offset); if (spaceToWrapAt >= 0) { wrappedLine.append(str.substring(offset, spaceToWrapAt)); wrappedLine.append(newLineStr); offset = spaceToWrapAt + 1; } else { wrappedLine.append(str.substring(offset)); offset = inputLineLength; } } } } // Whatever is left in line is short enough to just pass through wrappedLine.append(str.substring(offset)); return wrappedLine.toString(); } // Capitalizing // ----------------------------------------------------------------------- /** * <p> * Capitalizes all the whitespace separated words in a String. Only the * first letter of each word is changed. To convert the rest of each word to * lowercase at the same time, use {@link #capitalizeFully(String)}. * </p> * * <p> * Whitespace is defined by {@link Character#isWhitespace(char)}. A * <code>null</code> input String returns <code>null</code>. Capitalization * uses the Unicode title case, normally equivalent to upper case. * </p> * * <pre> * WordUtils.capitalize(null) = null * WordUtils.capitalize("") = "" * WordUtils.capitalize("i am FINE") = "I Am FINE" * </pre> * * @param str * the String to capitalize, may be null * @return capitalized String, <code>null</code> if null String input * @see #uncapitalize(String) * @see #capitalizeFully(String) */ public static String capitalize(final String str) { return capitalize(str, null); } /** * <p> * Capitalizes all the delimiter separated words in a String. Only the first * letter of each word is changed. To convert the rest of each word to * lowercase at the same time, use {@link #capitalizeFully(String, char[])}. * </p> * * <p> * The delimiters represent a set of characters understood to separate * words. The first string character and the first non-delimiter character * after a delimiter will be capitalized. * </p> * * <p> * A <code>null</code> input String returns <code>null</code>. * Capitalization uses the Unicode title case, normally equivalent to upper * case. * </p> * * <pre> * WordUtils.capitalize(null, *) = null * WordUtils.capitalize("", *) = "" * WordUtils.capitalize(*, new char[0]) = * * WordUtils.capitalize("i am fine", null) = "I Am Fine" * WordUtils.capitalize("i aM.fine", {'.'}) = "I aM.Fine" * </pre> * * @param str * the String to capitalize, may be null * @param delimiters * set of characters to determine capitalization, null means * whitespace * @return capitalized String, <code>null</code> if null String input * @see #uncapitalize(String) * @see #capitalizeFully(String) * @since 2.1 */ public static String capitalize(final String str, final char... delimiters) { final int delimLen = delimiters == null ? -1 : delimiters.length; if (StringUtils.isEmpty(str) || delimLen == 0) { return str; } final char[] buffer = str.toCharArray(); boolean capitalizeNext = true; for (int i = 0; i < buffer.length; i++) { final char ch = buffer[i]; if (isDelimiter(ch, delimiters)) { capitalizeNext = true; } else if (capitalizeNext) { buffer[i] = Character.toTitleCase(ch); capitalizeNext = false; } } return new String(buffer); } // ----------------------------------------------------------------------- /** * <p> * Converts all the whitespace separated words in a String into capitalized * words, that is each word is made up of a titlecase character and then a * series of lowercase characters. * </p> * * <p> * Whitespace is defined by {@link Character#isWhitespace(char)}. A * <code>null</code> input String returns <code>null</code>. Capitalization * uses the Unicode title case, normally equivalent to upper case. * </p> * * <pre> * WordUtils.capitalizeFully(null) = null * WordUtils.capitalizeFully("") = "" * WordUtils.capitalizeFully("i am FINE") = "I Am Fine" * </pre> * * @param str * the String to capitalize, may be null * @return capitalized String, <code>null</code> if null String input */ public static String capitalizeFully(final String str) { return capitalizeFully(str, null); } /** * <p> * Converts all the delimiter separated words in a String into capitalized * words, that is each word is made up of a titlecase character and then a * series of lowercase characters. * </p> * * <p> * The delimiters represent a set of characters understood to separate * words. The first string character and the first non-delimiter character * after a delimiter will be capitalized. * </p> * * <p> * A <code>null</code> input String returns <code>null</code>. * Capitalization uses the Unicode title case, normally equivalent to upper * case. * </p> * * <pre> * WordUtils.capitalizeFully(null, *) = null * WordUtils.capitalizeFully("", *) = "" * WordUtils.capitalizeFully(*, null) = * * WordUtils.capitalizeFully(*, new char[0]) = * * WordUtils.capitalizeFully("i aM.fine", {'.'}) = "I am.Fine" * </pre> * * @param str * the String to capitalize, may be null * @param delimiters * set of characters to determine capitalization, null means * whitespace * @return capitalized String, <code>null</code> if null String input * @since 2.1 */ public static String capitalizeFully(String str, final char... delimiters) { final int delimLen = delimiters == null ? -1 : delimiters.length; if (StringUtils.isEmpty(str) || delimLen == 0) { return str; } str = str.toLowerCase(Locale.ROOT); return capitalize(str, delimiters); } // ----------------------------------------------------------------------- /** * <p> * Uncapitalizes 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> * * <pre> * WordUtils.uncapitalize(null) = null * WordUtils.uncapitalize("") = "" * WordUtils.uncapitalize("I Am FINE") = "i am fINE" * </pre> * * @param str * the String to uncapitalize, may be null * @return uncapitalized String, <code>null</code> if null String input * @see #capitalize(String) */ public static String uncapitalize(final String str) { return uncapitalize(str, null); } /** * <p> * Uncapitalizes all the whitespace separated words in a String. Only the * first letter of each word is changed. * </p> * * <p> * The delimiters represent a set of characters understood to separate * words. The first string character and the first non-delimiter character * after a delimiter will be uncapitalized. * </p> * * <p> * Whitespace is defined by {@link Character#isWhitespace(char)}. A * <code>null</code> input String returns <code>null</code>. * </p> * * <pre> * WordUtils.uncapitalize(null, *) = null * WordUtils.uncapitalize("", *) = "" * WordUtils.uncapitalize(*, null) = * * WordUtils.uncapitalize(*, new char[0]) = * * WordUtils.uncapitalize("I AM.FINE", {'.'}) = "i AM.fINE" * </pre> * * @param str * the String to uncapitalize, may be null * @param delimiters * set of characters to determine uncapitalization, null means * whitespace * @return uncapitalized String, <code>null</code> if null String input * @see #capitalize(String) * @since 2.1 */ public static String uncapitalize(final String str, final char... delimiters) { final int delimLen = delimiters == null ? -1 : delimiters.length; if (StringUtils.isEmpty(str) || delimLen == 0) { return str; } final char[] buffer = str.toCharArray(); boolean uncapitalizeNext = true; for (int i = 0; i < buffer.length; i++) { final char ch = buffer[i]; if (isDelimiter(ch, delimiters)) { uncapitalizeNext = true; } else if (uncapitalizeNext) { buffer[i] = Character.toLowerCase(ch); uncapitalizeNext = false; } } return new String(buffer); } // ----------------------------------------------------------------------- /** * <p> * Swaps the case of a String using a word based algorithm. * </p> * * <ul> * <li>Upper case character converts to Lower case</li> * <li>Title case character converts to Lower case</li> * <li>Lower case character after Whitespace or at start converts to Title * case</li> * <li>Other Lower case character converts to Upper case</li> * </ul> * * <p> * Whitespace is defined by {@link Character#isWhitespace(char)}. 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> * * @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(final String str) { if (StringUtils.isEmpty(str)) { return str; } final char[] buffer = str.toCharArray(); boolean whitespace = true; for (int i = 0; i < buffer.length; i++) { final char ch = buffer[i]; if (Character.isUpperCase(ch)) { buffer[i] = Character.toLowerCase(ch); whitespace = false; } else if (Character.isTitleCase(ch)) { buffer[i] = Character.toLowerCase(ch); whitespace = false; } else if (Character.isLowerCase(ch)) { if (whitespace) { buffer[i] = Character.toTitleCase(ch); whitespace = false; } else { buffer[i] = Character.toUpperCase(ch); } } else { whitespace = Character.isWhitespace(ch); } } return new String(buffer); } // ----------------------------------------------------------------------- /** * <p> * Extracts the initial letters from each word in the String. * </p> * * <p> * The first letter of the string and all first letters after whitespace are * returned as a new string. Their case is not changed. * </p> * * <p> * Whitespace is defined by {@link Character#isWhitespace(char)}. A * <code>null</code> input String returns <code>null</code>. * </p> * * <pre> * WordUtils.initials(null) = null * WordUtils.initials("") = "" * WordUtils.initials("Ben John Lee") = "BJL" * WordUtils.initials("Ben J.Lee") = "BJ" * </pre> * * @param str * the String to get initials from, may be null * @return String of initial letters, <code>null</code> if null String input * @see #initials(String,char[]) * @since 2.2 */ public static String initials(final String str) { return initials(str, null); } /** * <p> * Extracts the initial letters from each word in the String. * </p> * * <p> * The first letter of the string and all first letters after the defined * delimiters are returned as a new string. Their case is not changed. * </p> * * <p> * If the delimiters array is null, then Whitespace is used. Whitespace is * defined by {@link Character#isWhitespace(char)}. A <code>null</code> * input String returns <code>null</code>. An empty delimiter array returns * an empty String. * </p> * * <pre> * WordUtils.initials(null, *) = null * WordUtils.initials("", *) = "" * WordUtils.initials("Ben John Lee", null) = "BJL" * WordUtils.initials("Ben J.Lee", null) = "BJ" * WordUtils.initials("Ben J.Lee", [' ','.']) = "BJL" * WordUtils.initials(*, new char[0]) = "" * </pre> * * @param str * the String to get initials from, may be null * @param delimiters * set of characters to determine words, null means whitespace * @return String of initial letters, <code>null</code> if null String input * @see #initials(String) * @since 2.2 */ public static String initials(final String str, final char... delimiters) { if (StringUtils.isEmpty(str)) { return str; } if (delimiters != null && delimiters.length == 0) { return ""; } final int strLen = str.length(); final char[] buf = new char[strLen / 2 + 1]; int count = 0; boolean lastWasGap = true; for (int i = 0; i < strLen; i++) { final char ch = str.charAt(i); if (isDelimiter(ch, delimiters)) { lastWasGap = true; } else if (lastWasGap) { buf[count++] = ch; lastWasGap = false; } else { continue; // ignore ch } } return new String(buf, 0, count); } // ----------------------------------------------------------------------- /** * Is the character a delimiter. * * @param ch * the character to check * @param delimiters * the delimiters * @return true if it is a delimiter */ private static boolean isDelimiter(final char ch, final char[] delimiters) { if (delimiters == null) { return Character.isWhitespace(ch); } for (final char delimiter : delimiters) { if (ch == delimiter) { return true; } } return false; } }