    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017package org.apache.commons.lang3.text;
    018
    019import java.util.regex.Matcher;
    020import java.util.regex.Pattern;
    021
    022import org.apache.commons.lang3.ArrayUtils;
    023import org.apache.commons.lang3.StringUtils;
    024
    025/**
    026 * Operations on Strings that contain words.
    027 *
    028 * <p>This class tries to handle {@code null} input gracefully.
    029 * An exception will not be thrown for a {@code null} input.
    030 * Each method documents its behavior in more detail.</p>
    031 *
    032 * @since 2.0
    033 * @deprecated As of 3.6, use Apache Commons Text
    034 * <a href="https://commons.apache.org/proper/commons-text/javadocs/api-release/org/apache/commons/text/WordUtils.html">
    035 * WordUtils</a> instead
    036 */
    037@Deprecated
    038public class WordUtils {
    039
    040    // Capitalizing
    041    /**
    042     * Capitalizes all the whitespace separated words in a String.
    043     * Only the first character of each word is changed. To convert the
    044     * rest of each word to lowercase at the same time,
    045     * use {@link #capitalizeFully(String)}.
    046     *
    047     * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.
    048     * A {@code null} input String returns {@code null}.
    049     * Capitalization uses the Unicode title case, normally equivalent to
    050     * upper case.</p>
    051     *
    052     * <pre>
    053     * WordUtils.capitalize(null)        = null
    054     * WordUtils.capitalize("")          = ""
    055     * WordUtils.capitalize("i am FINE") = "I Am FINE"
    056     * </pre>
    057     *
    058     * @param str  the String to capitalize, may be null
    059     * @return capitalized String, {@code null} if null String input
    060     * @see #uncapitalize(String)
    061     * @see #capitalizeFully(String)
    062     */
    063    public static String capitalize(final String str) {
    064        return capitalize(str, null);
    065    }
    066
    067    /**
    068     * Capitalizes all the delimiter separated words in a String.
    069     * Only the first character of each word is changed. To convert the
    070     * rest of each word to lowercase at the same time,
    071     * use {@link #capitalizeFully(String, char[])}.
    072     *
    073     * <p>The delimiters represent a set of characters understood to separate words.
    074     * The first string character and the first non-delimiter character after a
    075     * delimiter will be capitalized.</p>
    076     *
    077     * <p>A {@code null} input String returns {@code null}.
    078     * Capitalization uses the Unicode title case, normally equivalent to
    079     * upper case.</p>
    080     *
    081     * <pre>
    082     * WordUtils.capitalize(null, *)            = null
    083     * WordUtils.capitalize("", *)              = ""
    084     * WordUtils.capitalize(*, new char[0])     = *
    085     * WordUtils.capitalize("i am fine", null)  = "I Am Fine"
    086     * WordUtils.capitalize("i aM.fine", {'.'}) = "I aM.Fine"
    087     * </pre>
    088     *
    089     * @param str  the String to capitalize, may be null
    090     * @param delimiters  set of characters to determine capitalization, null means whitespace
    091     * @return capitalized String, {@code null} if null String input
    092     * @see #uncapitalize(String)
    093     * @see #capitalizeFully(String)
    094     * @since 2.1
    095     */
    096    public static String capitalize(final String str, final char... delimiters) {
    097        final int delimLen = delimiters == null ? -1 : delimiters.length;
    098        if (StringUtils.isEmpty(str) || delimLen == 0) {
    099            return str;
    100        }
    101        final char[] buffer = str.toCharArray();
    102        boolean capitalizeNext = true;
    103        for (int i = 0; i < buffer.length; i++) {
    104            final char ch = buffer[i];
    105            if (isDelimiter(ch, delimiters)) {
    106                capitalizeNext = true;
    107            } else if (capitalizeNext) {
    108                buffer[i] = Character.toTitleCase(ch);
    109                capitalizeNext = false;
    110            }
    111        }
    112        return new String(buffer);
    113    }
    114
    115    /**
    116     * Converts all the whitespace separated words in a String into capitalized words,
    117     * that is each word is made up of a titlecase character and then a series of
    118     * lowercase characters.
    119     *
    120     * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.
    121     * A {@code null} input String returns {@code null}.
    122     * Capitalization uses the Unicode title case, normally equivalent to
    123     * upper case.</p>
    124     *
    125     * <pre>
    126     * WordUtils.capitalizeFully(null)        = null
    127     * WordUtils.capitalizeFully("")          = ""
    128     * WordUtils.capitalizeFully("i am FINE") = "I Am Fine"
    129     * </pre>
    130     *
    131     * @param str  the String to capitalize, may be null
    132     * @return capitalized String, {@code null} if null String input
    133     */
    134    public static String capitalizeFully(final String str) {
    135        return capitalizeFully(str, null);
    136    }
    137
    138    /**
    139     * Converts all the delimiter separated words in a String into capitalized words,
    140     * that is each word is made up of a titlecase character and then a series of
    141     * lowercase characters.
    142     *
    143     * <p>The delimiters represent a set of characters understood to separate words.
    144     * The first string character and the first non-delimiter character after a
    145     * delimiter will be capitalized.</p>
    146     *
    147     * <p>A {@code null} input String returns {@code null}.
    148     * Capitalization uses the Unicode title case, normally equivalent to
    149     * upper case.</p>
    150     *
    151     * <pre>
    152     * WordUtils.capitalizeFully(null, *)            = null
    153     * WordUtils.capitalizeFully("", *)              = ""
    154     * WordUtils.capitalizeFully(*, null)            = *
    155     * WordUtils.capitalizeFully(*, new char[0])     = *
    156     * WordUtils.capitalizeFully("i aM.fine", {'.'}) = "I am.Fine"
    157     * </pre>
    158     *
    159     * @param str  the String to capitalize, may be null
    160     * @param delimiters  set of characters to determine capitalization, null means whitespace
    161     * @return capitalized String, {@code null} if null String input
    162     * @since 2.1
    163     */
    164    public static String capitalizeFully(final String str, final char... delimiters) {
    165        final int delimLen = delimiters == null ? -1 : delimiters.length;
    166        if (StringUtils.isEmpty(str) || delimLen == 0) {
    167            return str;
    168        }
    169        return capitalize(str.toLowerCase(), delimiters);
    170    }
    171
    172    /**
    173     * Checks if the String contains all words in the given array.
    174     *
    175     * <p>
    176     * A {@code null} String will return {@code false}. A {@code null}, zero
    177     * length search array or if one element of array is null will return {@code false}.
    178     * </p>
    179     *
    180     * <pre>
    181     * WordUtils.containsAllWords(null, *)            = false
    182     * WordUtils.containsAllWords("", *)              = false
    183     * WordUtils.containsAllWords(*, null)            = false
    184     * WordUtils.containsAllWords(*, [])              = false
    185     * WordUtils.containsAllWords("abcd", "ab", "cd") = false
    186     * WordUtils.containsAllWords("abc def", "def", "abc") = true
    187     * </pre>
    188     *
    189     * @param word The CharSequence to check, may be null
    190     * @param words The array of String words to search for, may be null
    191     * @return {@code true} if all search words are found, {@code false} otherwise
    192     * @since 3.5
    193     */
    194    public static boolean containsAllWords(final CharSequence word, final CharSequence... words) {
    195        if (StringUtils.isEmpty(word) || ArrayUtils.isEmpty(words)) {
    196            return false;
    197        }
    198        for (final CharSequence w : words) {
    199            if (StringUtils.isBlank(w)) {
    200                return false;
    201            }
    202            final Pattern p = Pattern.compile(".*\\b" + w + "\\b.*");
    203            if (!p.matcher(word).matches()) {
    204                return false;
    205            }
    206        }
    207        return true;
    208    }
    209
    210    /**
    211     * Extracts the initial characters from each word in the String.
    212     *
    213     * <p>All first characters after whitespace are returned as a new string.
    214     * Their case is not changed.</p>
    215     *
    216     * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.
    217     * A {@code null} input String returns {@code null}.</p>
    218     *
    219     * <pre>
    220     * WordUtils.initials(null)             = null
    221     * WordUtils.initials("")               = ""
    222     * WordUtils.initials("Ben John Lee")   = "BJL"
    223     * WordUtils.initials("Ben J.Lee")      = "BJ"
    224     * </pre>
    225     *
    226     * @param str  the String to get initials from, may be null
    227     * @return String of initial letters, {@code null} if null String input
    228     * @see #initials(String,char[])
    229     * @since 2.2
    230     */
    231    public static String initials(final String str) {
    232        return initials(str, null);
    233    }
    234
    235    /**
    236     * Extracts the initial characters from each word in the String.
    237     *
    238     * <p>All first characters after the defined delimiters are returned as a new string.
    239     * Their case is not changed.</p>
    240     *
    241     * <p>If the delimiters array is null, then Whitespace is used.
    242     * Whitespace is defined by {@link Character#isWhitespace(char)}.
    243     * A {@code null} input String returns {@code null}.
    244     * An empty delimiter array returns an empty String.</p>
    245     *
    246     * <pre>
    247     * WordUtils.initials(null, *)                = null
    248     * WordUtils.initials("", *)                  = ""
    249     * WordUtils.initials("Ben John Lee", null)   = "BJL"
    250     * WordUtils.initials("Ben J.Lee", null)      = "BJ"
    251     * WordUtils.initials("Ben J.Lee", [' ','.']) = "BJL"
    252     * WordUtils.initials(*, new char[0])         = ""
    253     * </pre>
    254     *
    255     * @param str  the String to get initials from, may be null
    256     * @param delimiters  set of characters to determine words, null means whitespace
    257     * @return String of initial characters, {@code null} if null String input
    258     * @see #initials(String)
    259     * @since 2.2
    260     */
    261    public static String initials(final String str, final char... delimiters) {
    262        if (StringUtils.isEmpty(str)) {
    263            return str;
    264        }
    265        if (delimiters != null && delimiters.length == 0) {
    266            return StringUtils.EMPTY;
    267        }
    268        final int strLen = str.length();
    269        final char[] buf = new char[strLen / 2 + 1];
    270        int count = 0;
    271        boolean lastWasGap = true;
    272        for (int i = 0; i < strLen; i++) {
    273            final char ch = str.charAt(i);
    274            if (isDelimiter(ch, delimiters)) {
    275                lastWasGap = true;
    276            } else if (lastWasGap) {
    277                buf[count++] = ch;
    278                lastWasGap = false;
    279            } else {
    280                continue; // ignore ch
    281            }
    282        }
    283        return new String(buf, 0, count);
    284    }
    285
    286    /**
    287     * Tests if the character is a delimiter.
    288     *
    289     * @param ch  the character to check
    290     * @param delimiters  the delimiters
    291     * @return true if it is a delimiter
    292     */
    293    private static boolean isDelimiter(final char ch, final char[] delimiters) {
    294        return delimiters == null ? Character.isWhitespace(ch) : ArrayUtils.contains(delimiters, ch);
    295    }
    296
    297    /**
    298     * Swaps the case of a String using a word based algorithm.
    299     *
    300     * <ul>
    301     *  <li>Upper case character converts to Lower case</li>
    302     *  <li>Title case character converts to Lower case</li>
    303     *  <li>Lower case character after Whitespace or at start converts to Title case</li>
    304     *  <li>Other Lower case character converts to Upper case</li>
    305     * </ul>
    306     *
    307     * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.
    308     * A {@code null} input String returns {@code null}.</p>
    309     *
    310     * <pre>
    311     * StringUtils.swapCase(null)                 = null
    312     * StringUtils.swapCase("")                   = ""
    313     * StringUtils.swapCase("The dog has a BONE") = "tHE DOG HAS A bone"
    314     * </pre>
    315     *
    316     * @param str  the String to swap case, may be null
    317     * @return the changed String, {@code null} if null String input
    318     */
    319    public static String swapCase(final String str) {
    320        if (StringUtils.isEmpty(str)) {
    321            return str;
    322        }
    323        final char[] buffer = str.toCharArray();
    324
    325        boolean whitespace = true;
    326
    327        for (int i = 0; i < buffer.length; i++) {
    328            final char ch = buffer[i];
    329            if (Character.isUpperCase(ch) || Character.isTitleCase(ch)) {
    330                buffer[i] = Character.toLowerCase(ch);
    331                whitespace = false;
    332            } else if (Character.isLowerCase(ch)) {
    333                if (whitespace) {
    334                    buffer[i] = Character.toTitleCase(ch);
    335                    whitespace = false;
    336                } else {
    337                    buffer[i] = Character.toUpperCase(ch);
    338                }
    339            } else {
    340                whitespace = Character.isWhitespace(ch);
    341            }
    342        }
    343        return new String(buffer);
    344    }
    345
    346    /**
    347     * Uncapitalizes all the whitespace separated words in a String.
    348     * Only the first character of each word is changed.
    349     *
    350     * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.
    351     * A {@code null} input String returns {@code null}.</p>
    352     *
    353     * <pre>
    354     * WordUtils.uncapitalize(null)        = null
    355     * WordUtils.uncapitalize("")          = ""
    356     * WordUtils.uncapitalize("I Am FINE") = "i am fINE"
    357     * </pre>
    358     *
    359     * @param str  the String to uncapitalize, may be null
    360     * @return uncapitalized String, {@code null} if null String input
    361     * @see #capitalize(String)
    362     */
    363    public static String uncapitalize(final String str) {
    364        return uncapitalize(str, null);
    365    }
    366
    367    /**
    368     * Uncapitalizes all the whitespace separated words in a String.
    369     * Only the first character of each word is changed.
    370     *
    371     * <p>The delimiters represent a set of characters understood to separate words.
    372     * The first string character and the first non-delimiter character after a
    373     * delimiter will be uncapitalized.</p>
    374     *
    375     * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.
    376     * A {@code null} input String returns {@code null}.</p>
    377     *
    378     * <pre>
    379     * WordUtils.uncapitalize(null, *)            = null
    380     * WordUtils.uncapitalize("", *)              = ""
    381     * WordUtils.uncapitalize(*, null)            = *
    382     * WordUtils.uncapitalize(*, new char[0])     = *
    383     * WordUtils.uncapitalize("I AM.FINE", {'.'}) = "i AM.fINE"
    384     * </pre>
    385     *
    386     * @param str  the String to uncapitalize, may be null
    387     * @param delimiters  set of characters to determine uncapitalization, null means whitespace
    388     * @return uncapitalized String, {@code null} if null String input
    389     * @see #capitalize(String)
    390     * @since 2.1
    391     */
    392    public static String uncapitalize(final String str, final char... delimiters) {
    393        final int delimLen = delimiters == null ? -1 : delimiters.length;
    394        if (StringUtils.isEmpty(str) || delimLen == 0) {
    395            return str;
    396        }
    397        final char[] buffer = str.toCharArray();
    398        boolean uncapitalizeNext = true;
    399        for (int i = 0; i < buffer.length; i++) {
    400            final char ch = buffer[i];
    401            if (isDelimiter(ch, delimiters)) {
    402                uncapitalizeNext = true;
    403            } else if (uncapitalizeNext) {
    404                buffer[i] = Character.toLowerCase(ch);
    405                uncapitalizeNext = false;
    406            }
    407        }
    408        return new String(buffer);
    409    }
    410
    411    /**
    412     * Wraps a single line of text, identifying words by {@code ' '}.
    413     *
    414     * <p>New lines will be separated by the system property line separator.
    415     * Very long words, such as URLs will <i>not</i> be wrapped.</p>
    416     *
    417     * <p>Leading spaces on a new line are stripped.
    418     * Trailing spaces are not stripped.</p>
    419     *
    420     * <table border="1">
    421     *  <caption>Examples</caption>
    422     *  <tr>
    423     *   <th>input</th>
    424     *   <th>wrapLength</th>
    425     *   <th>result</th>
    426     *  </tr>
    427     *  <tr>
    428     *   <td>null</td>
    429     *   <td>*</td>
    430     *   <td>null</td>
    431     *  </tr>
    432     *  <tr>
    433     *   <td>""</td>
    434     *   <td>*</td>
    435     *   <td>""</td>
    436     *  </tr>
    437     *  <tr>
    438     *   <td>"Here is one line of text that is going to be wrapped after 20 columns."</td>
    439     *   <td>20</td>
    440     *   <td>"Here is one line of\ntext that is going\nto be wrapped after\n20 columns."</td>
    441     *  </tr>
    442     *  <tr>
    443     *   <td>"Click here to jump to the commons website - https://commons.apache.org"</td>
    444     *   <td>20</td>
    445     *   <td>"Click here to jump\nto the commons\nwebsite -\nhttps://commons.apache.org"</td>
    446     *  </tr>
    447     *  <tr>
    448     *   <td>"Click here, https://commons.apache.org, to jump to the commons website"</td>
    449     *   <td>20</td>
    450     *   <td>"Click here,\nhttps://commons.apache.org,\nto jump to the\ncommons website"</td>
    451     *  </tr>
    452     * </table>
    453     *
    454     * (assuming that '\n' is the systems line separator)
    455     *
    456     * @param str  the String to be word wrapped, may be null
    457     * @param wrapLength  the column to wrap the words at, less than 1 is treated as 1
    458     * @return a line with newlines inserted, {@code null} if null input
    459     */
    460    public static String wrap(final String str, final int wrapLength) {
    461        return wrap(str, wrapLength, null, false);
    462    }
    463
    464    /**
    465     * Wraps a single line of text, identifying words by {@code ' '}.
    466     *
    467     * <p>Leading spaces on a new line are stripped.
    468     * Trailing spaces are not stripped.</p>
    469     *
    470     * <table border="1">
    471     *  <caption>Examples</caption>
    472     *  <tr>
    473     *   <th>input</th>
    474     *   <th>wrapLength</th>
    475     *   <th>newLineString</th>
    476     *   <th>wrapLongWords</th>
    477     *   <th>result</th>
    478     *  </tr>
    479     *  <tr>
    480     *   <td>null</td>
    481     *   <td>*</td>
    482     *   <td>*</td>
    483     *   <td>true/false</td>
    484     *   <td>null</td>
    485     *  </tr>
    486     *  <tr>
    487     *   <td>""</td>
    488     *   <td>*</td>
    489     *   <td>*</td>
    490     *   <td>true/false</td>
    491     *   <td>""</td>
    492     *  </tr>
    493     *  <tr>
    494     *   <td>"Here is one line of text that is going to be wrapped after 20 columns."</td>
    495     *   <td>20</td>
    496     *   <td>"\n"</td>
    497     *   <td>true/false</td>
    498     *   <td>"Here is one line of\ntext that is going\nto be wrapped after\n20 columns."</td>
    499     *  </tr>
    500     *  <tr>
    501     *   <td>"Here is one line of text that is going to be wrapped after 20 columns."</td>
    502     *   <td>20</td>
    503     *   <td>"&lt;br /&gt;"</td>
    504     *   <td>true/false</td>
    505     *   <td>"Here is one line of&lt;br /&gt;text that is going&lt;br /&gt;to be wrapped after&lt;br /&gt;20 columns."</td>
    506     *  </tr>
    507     *  <tr>
    508     *   <td>"Here is one line of text that is going to be wrapped after 20 columns."</td>
    509     *   <td>20</td>
    510     *   <td>null</td>
    511     *   <td>true/false</td>
    512     *   <td>"Here is one line of" + systemNewLine + "text that is going" + systemNewLine + "to be wrapped after" + systemNewLine + "20 columns."</td>
    513     *  </tr>
    514     *  <tr>
    515     *   <td>"Click here to jump to the commons website - https://commons.apache.org"</td>
    516     *   <td>20</td>
    517     *   <td>"\n"</td>
    518     *   <td>false</td>
    519     *   <td>"Click here to jump\nto the commons\nwebsite -\nhttps://commons.apache.org"</td>
    520     *  </tr>
    521     *  <tr>
    522     *   <td>"Click here to jump to the commons website - https://commons.apache.org"</td>
    523     *   <td>20</td>
    524     *   <td>"\n"</td>
    525     *   <td>true</td>
    526     *   <td>"Click here to jump\nto the commons\nwebsite -\nhttps://commons.apach\ne.org"</td>
    527     *  </tr>
    528     * </table>
    529     *
    530     * @param str  the String to be word wrapped, may be null
    531     * @param wrapLength  the column to wrap the words at, less than 1 is treated as 1
    532     * @param newLineStr  the string to insert for a new line,
    533     *  {@code null} uses the system property line separator
    534     * @param wrapLongWords  true if long words (such as URLs) should be wrapped
    535     * @return a line with newlines inserted, {@code null} if null input
    536     */
    537    public static String wrap(final String str, final int wrapLength, final String newLineStr, final boolean wrapLongWords) {
    538        return wrap(str, wrapLength, newLineStr, wrapLongWords, " ");
    539    }
    540
    541    /**
    542     * Wraps a single line of text, identifying words by {@code wrapOn}.
    543     *
    544     * <p>Leading spaces on a new line are stripped.
    545     * Trailing spaces are not stripped.</p>
    546     *
    547     * <table border="1">
    548     *  <caption>Examples</caption>
    549     *  <tr>
    550     *   <th>input</th>
    551     *   <th>wrapLength</th>
    552     *   <th>newLineString</th>
    553     *   <th>wrapLongWords</th>
    554     *   <th>wrapOn</th>
    555     *   <th>result</th>
    556     *  </tr>
    557     *  <tr>
    558     *   <td>null</td>
    559     *   <td>*</td>
    560     *   <td>*</td>
    561     *   <td>true/false</td>
    562     *   <td>*</td>
    563     *   <td>null</td>
    564     *  </tr>
    565     *  <tr>
    566     *   <td>""</td>
    567     *   <td>*</td>
    568     *   <td>*</td>
    569     *   <td>true/false</td>
    570     *   <td>*</td>
    571     *   <td>""</td>
    572     *  </tr>
    573     *  <tr>
    574     *   <td>"Here is one line of text that is going to be wrapped after 20 columns."</td>
    575     *   <td>20</td>
    576     *   <td>"\n"</td>
    577     *   <td>true/false</td>
    578     *   <td>" "</td>
    579     *   <td>"Here is one line of\ntext that is going\nto be wrapped after\n20 columns."</td>
    580     *  </tr>
    581     *  <tr>
    582     *   <td>"Here is one line of text that is going to be wrapped after 20 columns."</td>
    583     *   <td>20</td>
    584     *   <td>"&lt;br /&gt;"</td>
    585     *   <td>true/false</td>
    586     *   <td>" "</td>
    587     *   <td>"Here is one line of&lt;br /&gt;text that is going&lt;br /&gt;to be wrapped after&lt;br /&gt;20 columns."</td>
    588     *  </tr>
    589     *  <tr>
    590     *   <td>"Here is one line of text that is going to be wrapped after 20 columns."</td>
    591     *   <td>20</td>
    592     *   <td>null</td>
    593     *   <td>true/false</td>
    594     *   <td>" "</td>
    595     *   <td>"Here is one line of" + systemNewLine + "text that is going" + systemNewLine + "to be wrapped after" + systemNewLine + "20 columns."</td>
    596     *  </tr>
    597     *  <tr>
    598     *   <td>"Click here to jump to the commons website - https://commons.apache.org"</td>
    599     *   <td>20</td>
    600     *   <td>"\n"</td>
    601     *   <td>false</td>
    602     *   <td>" "</td>
    603     *   <td>"Click here to jump\nto the commons\nwebsite -\nhttps://commons.apache.org"</td>
    604     *  </tr>
    605     *  <tr>
    606     *   <td>"Click here to jump to the commons website - https://commons.apache.org"</td>
    607     *   <td>20</td>
    608     *   <td>"\n"</td>
    609     *   <td>true</td>
    610     *   <td>" "</td>
    611     *   <td>"Click here to jump\nto the commons\nwebsite -\nhttps://commons.apach\ne.org"</td>
    612     *  </tr>
    613     *  <tr>
    614     *   <td>"flammable/inflammable"</td>
    615     *   <td>20</td>
    616     *   <td>"\n"</td>
    617     *   <td>true</td>
    618     *   <td>"/"</td>
    619     *   <td>"flammable\ninflammable"</td>
    620     *  </tr>
    621     * </table>
    622     * @param str  the String to be word wrapped, may be null
    623     * @param wrapLength  the column to wrap the words at, less than 1 is treated as 1
    624     * @param newLineStr  the string to insert for a new line,
    625     *  {@code null} uses the system property line separator
    626     * @param wrapLongWords  true if long words (such as URLs) should be wrapped
    627     * @param wrapOn regex expression to be used as a breakable characters,
    628     *               if blank string is provided a space character will be used
    629     * @return a line with newlines inserted, {@code null} if null input
    630     */
    631    public static String wrap(final String str, int wrapLength, String newLineStr, final boolean wrapLongWords, String wrapOn) {
    632        if (str == null) {
    633            return null;
    634        }
    635        if (newLineStr == null) {
    636            newLineStr = System.lineSeparator();
    637        }
    638        if (wrapLength < 1) {
    639            wrapLength = 1;
    640        }
    641        if (StringUtils.isBlank(wrapOn)) {
    642            wrapOn = " ";
    643        }
    644        final Pattern patternToWrapOn = Pattern.compile(wrapOn);
    645        final int inputLineLength = str.length();
    646        int offset = 0;
    647        final StringBuilder wrappedLine = new StringBuilder(inputLineLength + 32);
    648
    649        while (offset < inputLineLength) {
    650            int spaceToWrapAt = -1;
    651            Matcher matcher = patternToWrapOn.matcher(
    652                str.substring(offset, Math.min((int) Math.min(Integer.MAX_VALUE, offset + wrapLength + 1L), inputLineLength)));
    653            if (matcher.find()) {
    654                if (matcher.start() == 0) {
    655                    offset += matcher.end();
    656                    continue;
    657                }
    658                spaceToWrapAt = matcher.start() + offset;
    659            }
    660
    661            // only last line without leading spaces is left
    662            if (inputLineLength - offset <= wrapLength) {
    663                break;
    664            }
    665
    666            while (matcher.find()) {
    667                spaceToWrapAt = matcher.start() + offset;
    668            }
    669
    670            if (spaceToWrapAt >= offset) {
    671                // normal case
    672                wrappedLine.append(str, offset, spaceToWrapAt);
    673                wrappedLine.append(newLineStr);
    674                offset = spaceToWrapAt + 1;
    675
    676            } else // really long word or URL
    677            if (wrapLongWords) {
    678                // wrap really long word one line at a time
    679                wrappedLine.append(str, offset, wrapLength + offset);
    680                wrappedLine.append(newLineStr);
    681                offset += wrapLength;
    682            } else {
    683                // do not wrap really long word, just extend beyond limit
    684                matcher = patternToWrapOn.matcher(str.substring(offset + wrapLength));
    685                if (matcher.find()) {
    686                    spaceToWrapAt = matcher.start() + offset + wrapLength;
    687                }
    688
    689                if (spaceToWrapAt >= 0) {
    690                    wrappedLine.append(str, offset, spaceToWrapAt);
    691                    wrappedLine.append(newLineStr);
    692                    offset = spaceToWrapAt + 1;
    693                } else {
    694                    wrappedLine.append(str, offset, str.length());
    695                    offset = inputLineLength;
    696                }
    697            }
    698        }
    699
    700        // Whatever is left in line is short enough to just pass through
    701        wrappedLine.append(str, offset, str.length());
    702
    703        return wrappedLine.toString();
    704    }
    705
    706    /**
    707     * {@link WordUtils} instances should NOT be constructed in
    708     * standard programming. Instead, the class should be used as
    709     * {@code WordUtils.wrap("foo bar", 20);}.
    710     *
    711     * <p>This constructor is public to permit tools that require a JavaBean
    712     * instance to operate.</p>
    713     */
    714    public WordUtils() {
    715    }
    716
    717}