    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 *      https://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.text;
    018
    019import java.util.HashSet;
    020import java.util.Set;
    021import java.util.function.Predicate;
    022import java.util.regex.Matcher;
    023import java.util.regex.Pattern;
    024
    025import org.apache.commons.lang3.ArrayUtils;
    026import org.apache.commons.lang3.StringUtils;
    027import org.apache.commons.lang3.Strings;
    028import org.apache.commons.lang3.Validate;
    029
    030/**
    031 * Operations on Strings that contain words.
    032 *
    033 * <p>
    034 * This class tries to handle {@code null} input gracefully. An exception will not be thrown for a
    035 * {@code null} input. Each method documents its behavior in more detail.
    036 * </p>
    037 *
    038 * @since 1.1
    039 */
    040public class WordUtils {
    041
    042    /**
    043     * Abbreviates the words nicely.
    044     *
    045     * <p>
    046     * This method searches for the first space after the lower limit and abbreviates
    047     * the String there. It will also append any String passed as a parameter
    048     * to the end of the String. The upper limit can be specified to forcibly
    049     * abbreviate a String.
    050     * </p>
    051     *
    052     * @param str         the string to be abbreviated. If null is passed, null is returned.
    053     *                    If the empty String is passed, the empty string is returned.
    054     * @param lower       the lower limit; negative value is treated as zero.
    055     * @param upper       the upper limit; specify -1 if no limit is desired.
    056     *                    The upper limit cannot be lower than the lower limit.
    057     * @param appendToEnd String to be appended to the end of the abbreviated string.
    058     *                    This is appended ONLY if the string was indeed abbreviated.
    059     *                    The append does not count towards the lower or upper limits.
    060     * @return The abbreviated String.
    061     *
    062     * <pre>
    063     * WordUtils.abbreviate("Now is the time for all good men", 0, 40, null));     = "Now"
    064     * WordUtils.abbreviate("Now is the time for all good men", 10, 40, null));    = "Now is the"
    065     * WordUtils.abbreviate("Now is the time for all good men", 20, 40, null));    = "Now is the time for all"
    066     * WordUtils.abbreviate("Now is the time for all good men", 0, 40, ""));       = "Now"
    067     * WordUtils.abbreviate("Now is the time for all good men", 10, 40, ""));      = "Now is the"
    068     * WordUtils.abbreviate("Now is the time for all good men", 20, 40, ""));      = "Now is the time for all"
    069     * WordUtils.abbreviate("Now is the time for all good men", 0, 40, " ..."));   = "Now ..."
    070     * WordUtils.abbreviate("Now is the time for all good men", 10, 40, " ..."));  = "Now is the ..."
    071     * WordUtils.abbreviate("Now is the time for all good men", 20, 40, " ..."));  = "Now is the time for all ..."
    072     * WordUtils.abbreviate("Now is the time for all good men", 0, -1, ""));       = "Now"
    073     * WordUtils.abbreviate("Now is the time for all good men", 10, -1, ""));      = "Now is the"
    074     * WordUtils.abbreviate("Now is the time for all good men", 20, -1, ""));      = "Now is the time for all"
    075     * WordUtils.abbreviate("Now is the time for all good men", 50, -1, ""));      = "Now is the time for all good men"
    076     * WordUtils.abbreviate("Now is the time for all good men", 1000, -1, ""));    = "Now is the time for all good men"
    077     * WordUtils.abbreviate("Now is the time for all good men", 9, -10, null));    = Throws {@link IllegalArgumentException}
    078     * WordUtils.abbreviate("Now is the time for all good men", 10, 5, null));     = Throws {@link IllegalArgumentException}
    079     * </pre>
    080     */
    081    public static String abbreviate(final String str, int lower, int upper, final String appendToEnd) {
    082        Validate.isTrue(upper >= -1, "upper value cannot be less than -1");
    083        Validate.isTrue(upper >= lower || upper == -1, "upper value is less than lower value");
    084        if (StringUtils.isEmpty(str)) {
    085            return str;
    086        }
    087
    088        // if the lower value is greater than the length of the string,
    089        // set to the length of the string
    090        if (lower > str.length()) {
    091            lower = str.length();
    092        }
    093
    094        // if the upper value is -1 (i.e. no limit) or is greater
    095        // than the length of the string, set to the length of the string
    096        if (upper == -1 || upper > str.length()) {
    097            upper = str.length();
    098        }
    099
    100        final StringBuilder result = new StringBuilder();
    101        final int index = Strings.CS.indexOf(str, " ", lower);
    102        if (index == -1) {
    103            result.append(str, 0, upper);
    104            // only if abbreviation has occurred do we append the appendToEnd value
    105            if (upper != str.length()) {
    106                result.append(StringUtils.defaultString(appendToEnd));
    107            }
    108        } else {
    109            result.append(str, 0, Math.min(index, upper));
    110            result.append(StringUtils.defaultString(appendToEnd));
    111        }
    112
    113        return result.toString();
    114    }
    115
    116    /**
    117     * Capitalizes all the whitespace separated words in a String.
    118     * Only the first character of each word is changed. To convert the
    119     * rest of each word to lowercase at the same time,
    120     * use {@link #capitalizeFully(String)}.
    121     *
    122     * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.
    123     * A {@code null} input String returns {@code null}.
    124     * Capitalization uses the Unicode title case, normally equivalent to
    125     * upper case.</p>
    126     *
    127     * <pre>
    128     * WordUtils.capitalize(null)        = null
    129     * WordUtils.capitalize("")          = ""
    130     * WordUtils.capitalize("i am FINE") = "I Am FINE"
    131     * </pre>
    132     *
    133     * @param str  the String to capitalize, may be null.
    134     * @return capitalized String, {@code null} if null String input.
    135     * @see #uncapitalize(String)
    136     * @see #capitalizeFully(String)
    137     */
    138    public static String capitalize(final String str) {
    139        return capitalize(str, null);
    140    }
    141
    142    /**
    143     * Capitalizes all the delimiter separated words in a String.
    144     * Only the first character of each word is changed. To convert the
    145     * rest of each word to lowercase at the same time,
    146     * use {@link #capitalizeFully(String, char[])}.
    147     *
    148     * <p>The delimiters represent a set of characters understood to separate words.
    149     * The first string character and the first non-delimiter character after a
    150     * delimiter will be capitalized.</p>
    151     *
    152     * <p>A {@code null} input String returns {@code null}.
    153     * Capitalization uses the Unicode title case, normally equivalent to
    154     * upper case.</p>
    155     *
    156     * <pre>
    157     * WordUtils.capitalize(null, *)            = null
    158     * WordUtils.capitalize("", *)              = ""
    159     * WordUtils.capitalize(*, new char[0])     = *
    160     * WordUtils.capitalize("i am fine", null)  = "I Am Fine"
    161     * WordUtils.capitalize("i aM.fine", {'.'}) = "I aM.Fine"
    162     * WordUtils.capitalize("i am fine", new char[]{}) = "I am fine"
    163     * </pre>
    164     *
    165     * @param str  the String to capitalize, may be null.
    166     * @param delimiters  set of characters to determine capitalization, null means whitespace.
    167     * @return capitalized String, {@code null} if null String input.
    168     * @see #uncapitalize(String)
    169     * @see #capitalizeFully(String)
    170     */
    171    public static String capitalize(final String str, final char... delimiters) {
    172        if (StringUtils.isEmpty(str)) {
    173            return str;
    174        }
    175        final Predicate<Integer> isDelimiter = generateIsDelimiterFunction(delimiters);
    176        final int strLen = str.length();
    177        final int[] newCodePoints = new int[strLen];
    178        int outOffset = 0;
    179
    180        boolean capitalizeNext = true;
    181        for (int index = 0; index < strLen;) {
    182            final int codePoint = str.codePointAt(index);
    183
    184            if (isDelimiter.test(codePoint)) {
    185                capitalizeNext = true;
    186                newCodePoints[outOffset++] = codePoint;
    187                index += Character.charCount(codePoint);
    188            } else if (capitalizeNext) {
    189                final int titleCaseCodePoint = Character.toTitleCase(codePoint);
    190                newCodePoints[outOffset++] = titleCaseCodePoint;
    191                index += Character.charCount(titleCaseCodePoint);
    192                capitalizeNext = false;
    193            } else {
    194                newCodePoints[outOffset++] = codePoint;
    195                index += Character.charCount(codePoint);
    196            }
    197        }
    198        return new String(newCodePoints, 0, outOffset);
    199    }
    200
    201    /**
    202     * Converts all the whitespace separated words in a String into capitalized words,
    203     * that is each word is made up of a titlecase character and then a series of
    204     * lowercase characters.
    205     *
    206     * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.
    207     * A {@code null} input String returns {@code null}.
    208     * Capitalization uses the Unicode title case, normally equivalent to
    209     * upper case.</p>
    210     *
    211     * <pre>
    212     * WordUtils.capitalizeFully(null)        = null
    213     * WordUtils.capitalizeFully("")          = ""
    214     * WordUtils.capitalizeFully("i am FINE") = "I Am Fine"
    215     * </pre>
    216     *
    217     * @param str  the String to capitalize, may be null.
    218     * @return capitalized String, {@code null} if null String input.
    219     */
    220    public static String capitalizeFully(final String str) {
    221        return capitalizeFully(str, null);
    222    }
    223
    224    /**
    225     * Converts all the delimiter separated words in a String into capitalized words,
    226     * that is each word is made up of a titlecase character and then a series of
    227     * lowercase characters.
    228     *
    229     * <p>The delimiters represent a set of characters understood to separate words.
    230     * The first string character and the first non-delimiter character after a
    231     * delimiter will be capitalized.</p>
    232     *
    233     * <p>A {@code null} input String returns {@code null}.
    234     * Capitalization uses the Unicode title case, normally equivalent to
    235     * upper case.</p>
    236     *
    237     * <pre>
    238     * WordUtils.capitalizeFully(null, *)            = null
    239     * WordUtils.capitalizeFully("", *)              = ""
    240     * WordUtils.capitalizeFully(*, null)            = *
    241     * WordUtils.capitalizeFully(*, new char[0])     = *
    242     * WordUtils.capitalizeFully("i aM.fine", {'.'}) = "I am.Fine"
    243     * </pre>
    244     *
    245     * @param str  the String to capitalize, may be null.
    246     * @param delimiters  set of characters to determine capitalization, null means whitespace.
    247     * @return capitalized String, {@code null} if null String input.
    248     */
    249    public static String capitalizeFully(String str, final char... delimiters) {
    250        if (StringUtils.isEmpty(str)) {
    251            return str;
    252        }
    253        str = str.toLowerCase();
    254        return capitalize(str, delimiters);
    255    }
    256
    257    /**
    258     * Checks if the String contains all words in the given array.
    259     *
    260     * <p>
    261     * A {@code null} String will return {@code false}. A {@code null}, zero
    262     * length search array or if one element of array is null will return {@code false}.
    263     * </p>
    264     *
    265     * <pre>
    266     * WordUtils.containsAllWords(null, *)            = false
    267     * WordUtils.containsAllWords("", *)              = false
    268     * WordUtils.containsAllWords(*, null)            = false
    269     * WordUtils.containsAllWords(*, [])              = false
    270     * WordUtils.containsAllWords("abcd", "ab", "cd") = false
    271     * WordUtils.containsAllWords("abc def", "def", "abc") = true
    272     * </pre>
    273     *
    274     * @param word The CharSequence to check, may be null.
    275     * @param words The array of String words to search for, may be null.
    276     * @return {@code true} if all search words are found, {@code false} otherwise.
    277     */
    278    public static boolean containsAllWords(final CharSequence word, final CharSequence... words) {
    279        if (StringUtils.isEmpty(word) || ArrayUtils.isEmpty(words)) {
    280            return false;
    281        }
    282        for (final CharSequence w : words) {
    283            if (StringUtils.isBlank(w)) {
    284                return false;
    285            }
    286            final Pattern p = Pattern.compile(".*\\b" + Pattern.quote(w.toString()) + "\\b.*");
    287            if (!p.matcher(word).matches()) {
    288                return false;
    289            }
    290        }
    291        return true;
    292    }
    293
    294    /**
    295     * Given the array of delimiters supplied; returns a function determining whether a character code point is a delimiter.
    296     * The function provides O(1) lookup time.
    297     * Whitespace is defined by {@link Character#isWhitespace(char)} and is used as the defaultvalue if delimiters is null.
    298     *
    299     * @param delimiters set of characters to determine delimiters, null means whitespace.
    300     * @return Predicate<Integer> taking a code point value as an argument and returning true if a delimiter.
    301     */
    302    private static Predicate<Integer> generateIsDelimiterFunction(final char[] delimiters) {
    303        final Predicate<Integer> isDelimiter;
    304        if (delimiters == null || delimiters.length == 0) {
    305            isDelimiter = delimiters == null ? Character::isWhitespace : c -> false;
    306        } else {
    307            final Set<Integer> delimiterSet = new HashSet<>();
    308            for (int index = 0; index < delimiters.length; index++) {
    309                delimiterSet.add(Character.codePointAt(delimiters, index));
    310            }
    311            isDelimiter = delimiterSet::contains;
    312        }
    313
    314        return isDelimiter;
    315    }
    316
    317    /**
    318     * Extracts the initial characters from each word in the String.
    319     *
    320     * <p>All first characters after whitespace are returned as a new string.
    321     * Their case is not changed.</p>
    322     *
    323     * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.
    324     * A {@code null} input String returns {@code null}.</p>
    325     *
    326     * <pre>
    327     * WordUtils.initials(null)             = null
    328     * WordUtils.initials("")               = ""
    329     * WordUtils.initials("Ben John Lee")   = "BJL"
    330     * WordUtils.initials("Ben J.Lee")      = "BJ"
    331     * </pre>
    332     *
    333     * @param str  the String to get initials from, may be null.
    334     * @return String of initial letters, {@code null} if null String input.
    335     * @see #initials(String,char[])
    336     */
    337    public static String initials(final String str) {
    338        return initials(str, null);
    339    }
    340
    341    /**
    342     * Extracts the initial characters from each word in the String.
    343     *
    344     * <p>All first characters after the defined delimiters are returned as a new string.
    345     * Their case is not changed.</p>
    346     *
    347     * <p>If the delimiters array is null, then Whitespace is used.
    348     * Whitespace is defined by {@link Character#isWhitespace(char)}.
    349     * A {@code null} input String returns {@code null}.
    350     * An empty delimiter array returns an empty String.</p>
    351     *
    352     * <pre>
    353     * WordUtils.initials(null, *)                = null
    354     * WordUtils.initials("", *)                  = ""
    355     * WordUtils.initials("Ben John Lee", null)   = "BJL"
    356     * WordUtils.initials("Ben J.Lee", null)      = "BJ"
    357     * WordUtils.initials("Ben J.Lee", [' ','.']) = "BJL"
    358     * WordUtils.initials(*, new char[0])         = ""
    359     * </pre>
    360     *
    361     * @param str  the String to get initials from, may be null.
    362     * @param delimiters  set of characters to determine words, null means whitespace.
    363     * @return String of initial characters, {@code null} if null String input.
    364     * @see #initials(String)
    365     */
    366    public static String initials(final String str, final char... delimiters) {
    367        if (StringUtils.isEmpty(str)) {
    368            return str;
    369        }
    370        if (delimiters != null && delimiters.length == 0) {
    371            return StringUtils.EMPTY;
    372        }
    373        final Predicate<Integer> isDelimiter = generateIsDelimiterFunction(delimiters);
    374        final int strLen = str.length();
    375        final int[] newCodePoints = new int[strLen / 2 + 1];
    376        int count = 0;
    377        boolean lastWasGap = true;
    378        for (int i = 0; i < strLen;) {
    379            final int codePoint = str.codePointAt(i);
    380
    381            if (isDelimiter.test(codePoint)) {
    382                lastWasGap = true;
    383            } else if (lastWasGap) {
    384                newCodePoints[count++] = codePoint;
    385                lastWasGap = false;
    386            }
    387
    388            i += Character.charCount(codePoint);
    389        }
    390        return new String(newCodePoints, 0, count);
    391    }
    392
    393    /**
    394     * Is the character a delimiter.
    395     *
    396     * @param ch the character to check.
    397     * @param delimiters the delimiters.
    398     * @return true if it is a delimiter.
    399     * @deprecated as of 1.2 and will be removed in 2.0.
    400     */
    401    @Deprecated
    402    public static boolean isDelimiter(final char ch, final char[] delimiters) {
    403        if (delimiters == null) {
    404            return Character.isWhitespace(ch);
    405        }
    406        for (final char delimiter : delimiters) {
    407            if (ch == delimiter) {
    408                return true;
    409            }
    410        }
    411        return false;
    412    }
    413
    414    /**
    415     * Is the codePoint a delimiter.
    416     *
    417     * @param codePoint the codePint to check.
    418     * @param delimiters the delimiters.
    419     * @return true if it is a delimiter.
    420     * @deprecated as of 1.2 and will be removed in 2.0.
    421     */
    422    @Deprecated
    423    public static boolean isDelimiter(final int codePoint, final char[] delimiters) {
    424        if (delimiters == null) {
    425            return Character.isWhitespace(codePoint);
    426        }
    427        for (int index = 0; index < delimiters.length; index++) {
    428            final int delimiterCodePoint = Character.codePointAt(delimiters, index);
    429            if (delimiterCodePoint == codePoint) {
    430                return true;
    431            }
    432        }
    433        return false;
    434    }
    435
    436    /**
    437     * Swaps the case of a String using a word based algorithm.
    438     *
    439     * <ul>
    440     *  <li>Upper case character converts to Lower case</li>
    441     *  <li>Title case character converts to Lower case</li>
    442     *  <li>Lower case character after Whitespace or at start converts to Title case</li>
    443     *  <li>Other Lower case character converts to Upper case</li>
    444     * </ul>
    445     *
    446     * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.
    447     * A {@code null} input String returns {@code null}.</p>
    448     *
    449     * <pre>
    450     * StringUtils.swapCase(null)                 = null
    451     * StringUtils.swapCase("")                   = ""
    452     * StringUtils.swapCase("The dog has a BONE") = "tHE DOG HAS A bone"
    453     * </pre>
    454     *
    455     * @param str  the String to swap case, may be null.
    456     * @return The changed String, {@code null} if null String input.
    457     */
    458    public static String swapCase(final String str) {
    459        if (StringUtils.isEmpty(str)) {
    460            return str;
    461        }
    462        final int strLen = str.length();
    463        final int[] newCodePoints = new int[strLen];
    464        int outOffset = 0;
    465        boolean whitespace = true;
    466        for (int index = 0; index < strLen;) {
    467            final int oldCodepoint = str.codePointAt(index);
    468            final int newCodePoint;
    469            if (Character.isUpperCase(oldCodepoint) || Character.isTitleCase(oldCodepoint)) {
    470                newCodePoint = Character.toLowerCase(oldCodepoint);
    471                whitespace = false;
    472            } else if (Character.isLowerCase(oldCodepoint)) {
    473                if (whitespace) {
    474                    newCodePoint = Character.toTitleCase(oldCodepoint);
    475                    whitespace = false;
    476                } else {
    477                    newCodePoint = Character.toUpperCase(oldCodepoint);
    478                }
    479            } else {
    480                whitespace = Character.isWhitespace(oldCodepoint);
    481                newCodePoint = oldCodepoint;
    482            }
    483            newCodePoints[outOffset++] = newCodePoint;
    484            index += Character.charCount(newCodePoint);
    485        }
    486        return new String(newCodePoints, 0, outOffset);
    487    }
    488
    489    /**
    490     * Uncapitalizes all the whitespace separated words in a String.
    491     * Only the first character of each word is changed.
    492     *
    493     * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.
    494     * A {@code null} input String returns {@code null}.</p>
    495     *
    496     * <pre>
    497     * WordUtils.uncapitalize(null)        = null
    498     * WordUtils.uncapitalize("")          = ""
    499     * WordUtils.uncapitalize("I Am FINE") = "i am fINE"
    500     * </pre>
    501     *
    502     * @param str  the String to uncapitalize, may be null.
    503     * @return uncapitalized String, {@code null} if null String input.
    504     * @see #capitalize(String)
    505     */
    506    public static String uncapitalize(final String str) {
    507        return uncapitalize(str, null);
    508    }
    509
    510    /**
    511     * Uncapitalizes all the whitespace separated words in a String.
    512     * Only the first character of each word is changed.
    513     *
    514     * <p>The delimiters represent a set of characters understood to separate words.
    515     * The first string character and the first non-delimiter character after a
    516     * delimiter will be uncapitalized.</p>
    517     *
    518     * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.
    519     * A {@code null} input String returns {@code null}.</p>
    520     *
    521     * <pre>
    522     * WordUtils.uncapitalize(null, *)            = null
    523     * WordUtils.uncapitalize("", *)              = ""
    524     * WordUtils.uncapitalize(*, null)            = *
    525     * WordUtils.uncapitalize(*, new char[0])     = *
    526     * WordUtils.uncapitalize("I AM.FINE", {'.'}) = "i AM.fINE"
    527     * WordUtils.uncapitalize("I am fine", new char[]{}) = "i am fine"
    528     * </pre>
    529     *
    530     * @param str  the String to uncapitalize, may be null.
    531     * @param delimiters  set of characters to determine uncapitalization, null means whitespace.
    532     * @return uncapitalized String, {@code null} if null String input.
    533     * @see #capitalize(String)
    534     */
    535    public static String uncapitalize(final String str, final char... delimiters) {
    536        if (StringUtils.isEmpty(str)) {
    537            return str;
    538        }
    539        final Predicate<Integer> isDelimiter = generateIsDelimiterFunction(delimiters);
    540        final int strLen = str.length();
    541        final int[] newCodePoints = new int[strLen];
    542        int outOffset = 0;
    543
    544        boolean uncapitalizeNext = true;
    545        for (int index = 0; index < strLen;) {
    546            final int codePoint = str.codePointAt(index);
    547
    548            if (isDelimiter.test(codePoint)) {
    549                uncapitalizeNext = true;
    550                newCodePoints[outOffset++] = codePoint;
    551                index += Character.charCount(codePoint);
    552            } else if (uncapitalizeNext) {
    553                final int titleCaseCodePoint = Character.toLowerCase(codePoint);
    554                newCodePoints[outOffset++] = titleCaseCodePoint;
    555                index += Character.charCount(titleCaseCodePoint);
    556                uncapitalizeNext = false;
    557            } else {
    558                newCodePoints[outOffset++] = codePoint;
    559                index += Character.charCount(codePoint);
    560            }
    561        }
    562        return new String(newCodePoints, 0, outOffset);
    563    }
    564
    565    /**
    566     * Wraps a single line of text, identifying words by {@code ' '}.
    567     *
    568     * <p>New lines will be separated by the system property line separator.
    569     * Very long words, such as URLs will <em>not</em> be wrapped.</p>
    570     *
    571     * <p>Leading spaces on a new line are stripped.
    572     * Trailing spaces are not stripped.</p>
    573     *
    574     * <table border="1">
    575     *  <caption>Examples</caption>
    576     *  <tr>
    577     *   <th>input</th>
    578     *   <th>wrapLength</th>
    579     *   <th>result</th>
    580     *  </tr>
    581     *  <tr>
    582     *   <td>null</td>
    583     *   <td>*</td>
    584     *   <td>null</td>
    585     *  </tr>
    586     *  <tr>
    587     *   <td>""</td>
    588     *   <td>*</td>
    589     *   <td>""</td>
    590     *  </tr>
    591     *  <tr>
    592     *   <td>"Here is one line of text that is going to be wrapped after 20 columns."</td>
    593     *   <td>20</td>
    594     *   <td>"Here is one line of\ntext that is going\nto be wrapped after\n20 columns."</td>
    595     *  </tr>
    596     *  <tr>
    597     *   <td>"Click here to jump to the commons website - https://commons.apache.org"</td>
    598     *   <td>20</td>
    599     *   <td>"Click here to jump\nto the commons\nwebsite -\nhttps://commons.apache.org"</td>
    600     *  </tr>
    601     *  <tr>
    602     *   <td>"Click here, https://commons.apache.org, to jump to the commons website"</td>
    603     *   <td>20</td>
    604     *   <td>"Click here,\nhttps://commons.apache.org,\nto jump to the\ncommons website"</td>
    605     *  </tr>
    606     * </table>
    607     *
    608     * (assuming that '\n' is the systems line separator)
    609     *
    610     * @param str  the String to be word wrapped, may be null.
    611     * @param wrapLength  the column to wrap the words at, less than 1 is treated as 1.
    612     * @return a line with newlines inserted, {@code null} if null input.
    613     */
    614    public static String wrap(final String str, final int wrapLength) {
    615        return wrap(str, wrapLength, null, false);
    616    }
    617
    618    /**
    619     * Wraps a single line of text, identifying words by {@code ' '}.
    620     *
    621     * <p>Leading spaces on a new line are stripped.
    622     * Trailing spaces are not stripped.</p>
    623     *
    624     * <table border="1">
    625     *  <caption>Examples</caption>
    626     *  <tr>
    627     *   <th>input</th>
    628     *   <th>wrapLength</th>
    629     *   <th>newLineString</th>
    630     *   <th>wrapLongWords</th>
    631     *   <th>result</th>
    632     *  </tr>
    633     *  <tr>
    634     *   <td>null</td>
    635     *   <td>*</td>
    636     *   <td>*</td>
    637     *   <td>true/false</td>
    638     *   <td>null</td>
    639     *  </tr>
    640     *  <tr>
    641     *   <td>""</td>
    642     *   <td>*</td>
    643     *   <td>*</td>
    644     *   <td>true/false</td>
    645     *   <td>""</td>
    646     *  </tr>
    647     *  <tr>
    648     *   <td>"Here is one line of text that is going to be wrapped after 20 columns."</td>
    649     *   <td>20</td>
    650     *   <td>"\n"</td>
    651     *   <td>true/false</td>
    652     *   <td>"Here is one line of\ntext that is going\nto be wrapped after\n20 columns."</td>
    653     *  </tr>
    654     *  <tr>
    655     *   <td>"Here is one line of text that is going to be wrapped after 20 columns."</td>
    656     *   <td>20</td>
    657     *   <td>"&lt;br /&gt;"</td>
    658     *   <td>true/false</td>
    659     *   <td>"Here is one line of&lt;br /&gt;text that is going&lt;
    660     *   br /&gt;to be wrapped after&lt;br /&gt;20 columns."</td>
    661     *  </tr>
    662     *  <tr>
    663     *   <td>"Here is one line of text that is going to be wrapped after 20 columns."</td>
    664     *   <td>20</td>
    665     *   <td>null</td>
    666     *   <td>true/false</td>
    667     *   <td>"Here is one line of" + systemNewLine + "text that is going"
    668     *   + systemNewLine + "to be wrapped after" + systemNewLine + "20 columns."</td>
    669     *  </tr>
    670     *  <tr>
    671     *   <td>"Click here to jump to the commons website - https://commons.apache.org"</td>
    672     *   <td>20</td>
    673     *   <td>"\n"</td>
    674     *   <td>false</td>
    675     *   <td>"Click here to jump\nto the commons\nwebsite -\nhttps://commons.apache.org"</td>
    676     *  </tr>
    677     *  <tr>
    678     *   <td>"Click here to jump to the commons website - https://commons.apache.org"</td>
    679     *   <td>20</td>
    680     *   <td>"\n"</td>
    681     *   <td>true</td>
    682     *   <td>"Click here to jump\nto the commons\nwebsite -\nhttps://commons.apach\ne.org"</td>
    683     *  </tr>
    684     * </table>
    685     *
    686     * @param str  the String to be word wrapped, may be null.
    687     * @param wrapLength  the column to wrap the words at, less than 1 is treated as 1.
    688     * @param newLineStr  the string to insert for a new line, {@code null} uses the system property line separator.
    689     * @param wrapLongWords  true if long words (such as URLs) should be wrapped.
    690     * @return a line with newlines inserted, {@code null} if null input.
    691     */
    692    public static String wrap(final String str,
    693                              final int wrapLength,
    694                              final String newLineStr,
    695                              final boolean wrapLongWords) {
    696        return wrap(str, wrapLength, newLineStr, wrapLongWords, " ");
    697    }
    698
    699    /**
    700     * Wraps a single line of text, identifying words by {@code wrapOn}.
    701     *
    702     * <p>Leading spaces on a new line are stripped.
    703     * Trailing spaces are not stripped.</p>
    704     *
    705     * <table border="1">
    706     *  <caption>Examples</caption>
    707     *  <tr>
    708     *   <th>input</th>
    709     *   <th>wrapLength</th>
    710     *   <th>newLineString</th>
    711     *   <th>wrapLongWords</th>
    712     *   <th>wrapOn</th>
    713     *   <th>result</th>
    714     *  </tr>
    715     *  <tr>
    716     *   <td>null</td>
    717     *   <td>*</td>
    718     *   <td>*</td>
    719     *   <td>true/false</td>
    720     *   <td>*</td>
    721     *   <td>null</td>
    722     *  </tr>
    723     *  <tr>
    724     *   <td>""</td>
    725     *   <td>*</td>
    726     *   <td>*</td>
    727     *   <td>true/false</td>
    728     *   <td>*</td>
    729     *   <td>""</td>
    730     *  </tr>
    731     *  <tr>
    732     *   <td>"Here is one line of text that is going to be wrapped after 20 columns."</td>
    733     *   <td>20</td>
    734     *   <td>"\n"</td>
    735     *   <td>true/false</td>
    736     *   <td>" "</td>
    737     *   <td>"Here is one line of\ntext that is going\nto be wrapped after\n20 columns."</td>
    738     *  </tr>
    739     *  <tr>
    740     *   <td>"Here is one line of text that is going to be wrapped after 20 columns."</td>
    741     *   <td>20</td>
    742     *   <td>"&lt;br /&gt;"</td>
    743     *   <td>true/false</td>
    744     *   <td>" "</td>
    745     *   <td>"Here is one line of&lt;br /&gt;text that is going&lt;br /&gt;
    746     *   to be wrapped after&lt;br /&gt;20 columns."</td>
    747     *  </tr>
    748     *  <tr>
    749     *   <td>"Here is one line of text that is going to be wrapped after 20 columns."</td>
    750     *   <td>20</td>
    751     *   <td>null</td>
    752     *   <td>true/false</td>
    753     *   <td>" "</td>
    754     *   <td>"Here is one line of" + systemNewLine + "text that is going"
    755     *   + systemNewLine + "to be wrapped after" + systemNewLine + "20 columns."</td>
    756     *  </tr>
    757     *  <tr>
    758     *   <td>"Click here to jump to the commons website - https://commons.apache.org"</td>
    759     *   <td>20</td>
    760     *   <td>"\n"</td>
    761     *   <td>false</td>
    762     *   <td>" "</td>
    763     *   <td>"Click here to jump\nto the commons\nwebsite -\nhttps://commons.apache.org"</td>
    764     *  </tr>
    765     *  <tr>
    766     *   <td>"Click here to jump to the commons website - https://commons.apache.org"</td>
    767     *   <td>20</td>
    768     *   <td>"\n"</td>
    769     *   <td>true</td>
    770     *   <td>" "</td>
    771     *   <td>"Click here to jump\nto the commons\nwebsite -\nhttps://commons.apach\ne.org"</td>
    772     *  </tr>
    773     *  <tr>
    774     *   <td>"flammable/inflammable"</td>
    775     *   <td>20</td>
    776     *   <td>"\n"</td>
    777     *   <td>true</td>
    778     *   <td>"/"</td>
    779     *   <td>"flammable\ninflammable"</td>
    780     *  </tr>
    781     * </table>
    782     * @param str  the String to be word wrapped, may be null.
    783     * @param wrapLength  the column to wrap the words at, less than 1 is treated as 1.
    784     * @param newLineStr  the string to insert for a new line, {@code null} uses the system property line separator.
    785     * @param wrapLongWords  true if long words (such as URLs) should be wrapped.
    786     * @param wrapOn regex expression to be used as a breakable characters, if blank string is provided a space character will be used.
    787     * @return a line with newlines inserted, {@code null} if null input.
    788     */
    789    public static String wrap(final String str,
    790                              int wrapLength,
    791                              String newLineStr,
    792                              final boolean wrapLongWords,
    793                              String wrapOn) {
    794        if (str == null) {
    795            return null;
    796        }
    797        if (newLineStr == null) {
    798            newLineStr = System.lineSeparator();
    799        }
    800        if (wrapLength < 1) {
    801            wrapLength = 1;
    802        }
    803        if (StringUtils.isBlank(wrapOn)) {
    804            wrapOn = " ";
    805        }
    806        final Pattern patternToWrapOn = Pattern.compile(wrapOn);
    807        final int inputLineLength = str.length();
    808        int offset = 0;
    809        final StringBuilder wrappedLine = new StringBuilder(inputLineLength + 32);
    810        int matcherSize = -1;
    811
    812        while (offset < inputLineLength) {
    813            int spaceToWrapAt = -1;
    814            Matcher matcher = patternToWrapOn.matcher(str.substring(offset,
    815                    Math.min((int) Math.min(Integer.MAX_VALUE, offset + wrapLength + 1L), inputLineLength)));
    816            if (matcher.find()) {
    817                if (matcher.start() == 0) {
    818                    matcherSize = matcher.end();
    819                    if (matcherSize != 0) {
    820                        offset += matcher.end();
    821                        continue;
    822                    }
    823                    offset += 1;
    824                }
    825                spaceToWrapAt = matcher.start() + offset;
    826            }
    827
    828            // only last line without leading spaces is left
    829            if (inputLineLength - offset <= wrapLength) {
    830                break;
    831            }
    832
    833            while (matcher.find()) {
    834                spaceToWrapAt = matcher.start() + offset;
    835            }
    836
    837            if (spaceToWrapAt >= offset) {
    838                // normal case
    839                wrappedLine.append(str, offset, spaceToWrapAt);
    840                wrappedLine.append(newLineStr);
    841                offset = spaceToWrapAt + 1;
    842
    843            } else // really long word or URL
    844            if (wrapLongWords) {
    845                if (matcherSize == 0) {
    846                    offset--;
    847                }
    848                // wrap really long word one line at a time
    849                wrappedLine.append(str, offset, wrapLength + offset);
    850                wrappedLine.append(newLineStr);
    851                offset += wrapLength;
    852                matcherSize = -1;
    853            } else {
    854                // do not wrap really long word, just extend beyond limit
    855                matcher = patternToWrapOn.matcher(str.substring(offset + wrapLength));
    856                if (matcher.find()) {
    857                    matcherSize = matcher.end() - matcher.start();
    858                    spaceToWrapAt = matcher.start() + offset + wrapLength;
    859                }
    860
    861                if (spaceToWrapAt >= 0) {
    862                    if (matcherSize == 0 && offset != 0) {
    863                        offset--;
    864                    }
    865                    wrappedLine.append(str, offset, spaceToWrapAt);
    866                    wrappedLine.append(newLineStr);
    867                    offset = spaceToWrapAt + 1;
    868                } else {
    869                    if (matcherSize == 0 && offset != 0) {
    870                        offset--;
    871                    }
    872                    wrappedLine.append(str, offset, str.length());
    873                    offset = inputLineLength;
    874                    matcherSize = -1;
    875                }
    876            }
    877        }
    878
    879        if (matcherSize == 0 && offset < inputLineLength) {
    880            offset--;
    881        }
    882
    883        // Whatever is left in line is short enough to just pass through
    884        wrappedLine.append(str, offset, str.length());
    885
    886        return wrappedLine.toString();
    887    }
    888
    889    /**
    890     * {@code WordUtils} instances should NOT be constructed in
    891     * standard programming. Instead, the class should be used as
    892     * {@code WordUtils.wrap("foo bar", 20);}.
    893     *
    894     * <p>This constructor is public to permit tools that require a JavaBean
    895     * instance to operate.</p>
    896     */
    897    public WordUtils() {
    898    }
    899 }