    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     */
    017    package org.apache.commons.lang3.text;
    018
    019    import org.apache.commons.lang3.StringUtils;
    020    import org.apache.commons.lang3.SystemUtils;
    021
    022    /**
    023     * <p>Operations on Strings that contain words.</p>
    024     *
    025     * <p>This class tries to handle <code>null</code> input gracefully.
    026     * An exception will not be thrown for a <code>null</code> input.
    027     * Each method documents its behaviour in more detail.</p>
    028     *
    029     * @author Apache Software Foundation
    030     * @author Apache Jakarta Velocity
    031     * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
    032     * @author Gary Gregory
    033     * @since 2.0
    034     * @version $Id: WordUtils.java 925967 2010-03-22 06:16:49Z bayard $
    035     */
    036    public class WordUtils {
    037
    038        /**
    039         * <p><code>WordUtils</code> instances should NOT be constructed in
    040         * standard programming. Instead, the class should be used as
    041         * <code>WordUtils.wrap("foo bar", 20);</code>.</p>
    042         *
    043         * <p>This constructor is public to permit tools that require a JavaBean
    044         * instance to operate.</p>
    045         */
    046        public WordUtils() {
    047          super();
    048        }
    049
    050        // Wrapping
    051        //--------------------------------------------------------------------------
    052        /**
    053         * <p>Wraps a single line of text, identifying words by <code>' '</code>.</p>
    054         *
    055         * <p>New lines will be separated by the system property line separator.
    056         * Very long words, such as URLs will <i>not</i> be wrapped.</p>
    057         *
    058         * <p>Leading spaces on a new line are stripped.
    059         * Trailing spaces are not stripped.</p>
    060         *
    061         * <pre>
    062         * WordUtils.wrap(null, *) = null
    063         * WordUtils.wrap("", *) = ""
    064         * </pre>
    065         *
    066         * @param str  the String to be word wrapped, may be null
    067         * @param wrapLength  the column to wrap the words at, less than 1 is treated as 1
    068         * @return a line with newlines inserted, <code>null</code> if null input
    069         */
    070        public static String wrap(String str, int wrapLength) {
    071            return wrap(str, wrapLength, null, false);
    072        }
    073
    074        /**
    075         * <p>Wraps a single line of text, identifying words by <code>' '</code>.</p>
    076         *
    077         * <p>Leading spaces on a new line are stripped.
    078         * Trailing spaces are not stripped.</p>
    079         *
    080         * <pre>
    081         * WordUtils.wrap(null, *, *, *) = null
    082         * WordUtils.wrap("", *, *, *) = ""
    083         * </pre>
    084         *
    085         * @param str  the String to be word wrapped, may be null
    086         * @param wrapLength  the column to wrap the words at, less than 1 is treated as 1
    087         * @param newLineStr  the string to insert for a new line,
    088         *  <code>null</code> uses the system property line separator
    089         * @param wrapLongWords  true if long words (such as URLs) should be wrapped
    090         * @return a line with newlines inserted, <code>null</code> if null input
    091         */
    092        public static String wrap(String str, int wrapLength, String newLineStr, boolean wrapLongWords) {
    093            if (str == null) {
    094                return null;
    095            }
    096            if (newLineStr == null) {
    097                newLineStr = SystemUtils.LINE_SEPARATOR;
    098            }
    099            if (wrapLength < 1) {
    100                wrapLength = 1;
    101            }
    102            int inputLineLength = str.length();
    103            int offset = 0;
    104            StringBuilder wrappedLine = new StringBuilder(inputLineLength + 32);
    105
    106            while ((inputLineLength - offset) > wrapLength) {
    107                if (str.charAt(offset) == ' ') {
    108                    offset++;
    109                    continue;
    110                }
    111                int spaceToWrapAt = str.lastIndexOf(' ', wrapLength + offset);
    112
    113                if (spaceToWrapAt >= offset) {
    114                    // normal case
    115                    wrappedLine.append(str.substring(offset, spaceToWrapAt));
    116                    wrappedLine.append(newLineStr);
    117                    offset = spaceToWrapAt + 1;
    118
    119                } else {
    120                    // really long word or URL
    121                    if (wrapLongWords) {
    122                        // wrap really long word one line at a time
    123                        wrappedLine.append(str.substring(offset, wrapLength + offset));
    124                        wrappedLine.append(newLineStr);
    125                        offset += wrapLength;
    126                    } else {
    127                        // do not wrap really long word, just extend beyond limit
    128                        spaceToWrapAt = str.indexOf(' ', wrapLength + offset);
    129                        if (spaceToWrapAt >= 0) {
    130                            wrappedLine.append(str.substring(offset, spaceToWrapAt));
    131                            wrappedLine.append(newLineStr);
    132                            offset = spaceToWrapAt + 1;
    133                        } else {
    134                            wrappedLine.append(str.substring(offset));
    135                            offset = inputLineLength;
    136                        }
    137                    }
    138                }
    139            }
    140
    141            // Whatever is left in line is short enough to just pass through
    142            wrappedLine.append(str.substring(offset));
    143
    144            return wrappedLine.toString();
    145        }
    146
    147        // Capitalizing
    148        //-----------------------------------------------------------------------
    149        /**
    150         * <p>Capitalizes all the whitespace separated words in a String.
    151         * Only the first letter of each word is changed. To convert the
    152         * rest of each word to lowercase at the same time,
    153         * use {@link #capitalizeFully(String)}.</p>
    154         *
    155         * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.
    156         * A <code>null</code> input String returns <code>null</code>.
    157         * Capitalization uses the unicode title case, normally equivalent to
    158         * upper case.</p>
    159         *
    160         * <pre>
    161         * WordUtils.capitalize(null)        = null
    162         * WordUtils.capitalize("")          = ""
    163         * WordUtils.capitalize("i am FINE") = "I Am FINE"
    164         * </pre>
    165         *
    166         * @param str  the String to capitalize, may be null
    167         * @return capitalized String, <code>null</code> if null String input
    168         * @see #uncapitalize(String)
    169         * @see #capitalizeFully(String)
    170         */
    171        public static String capitalize(String str) {
    172            return capitalize(str, null);
    173        }
    174
    175        /**
    176         * <p>Capitalizes all the delimiter separated words in a String.
    177         * Only the first letter of each word is changed. To convert the
    178         * rest of each word to lowercase at the same time,
    179         * use {@link #capitalizeFully(String, char[])}.</p>
    180         *
    181         * <p>The delimiters represent a set of characters understood to separate words.
    182         * The first string character and the first non-delimiter character after a
    183         * delimiter will be capitalized. </p>
    184         *
    185         * <p>A <code>null</code> input String returns <code>null</code>.
    186         * Capitalization uses the unicode title case, normally equivalent to
    187         * upper case.</p>
    188         *
    189         * <pre>
    190         * WordUtils.capitalize(null, *)            = null
    191         * WordUtils.capitalize("", *)              = ""
    192         * WordUtils.capitalize(*, new char[0])     = *
    193         * WordUtils.capitalize("i am fine", null)  = "I Am Fine"
    194         * WordUtils.capitalize("i aM.fine", {'.'}) = "I aM.Fine"
    195         * </pre>
    196         *
    197         * @param str  the String to capitalize, may be null
    198         * @param delimiters  set of characters to determine capitalization, null means whitespace
    199         * @return capitalized String, <code>null</code> if null String input
    200         * @see #uncapitalize(String)
    201         * @see #capitalizeFully(String)
    202         * @since 2.1
    203         */
    204        public static String capitalize(String str, char... delimiters) {
    205            int delimLen = (delimiters == null ? -1 : delimiters.length);
    206            if (str == null || str.length() == 0 || delimLen == 0) {
    207                return str;
    208            }
    209            int strLen = str.length();
    210            StringBuilder buffer = new StringBuilder(strLen);
    211            boolean capitalizeNext = true;
    212            for (int i = 0; i < strLen; i++) {
    213                char ch = str.charAt(i);
    214
    215                if (isDelimiter(ch, delimiters)) {
    216                    buffer.append(ch);
    217                    capitalizeNext = true;
    218                } else if (capitalizeNext) {
    219                    buffer.append(Character.toTitleCase(ch));
    220                    capitalizeNext = false;
    221                } else {
    222                    buffer.append(ch);
    223                }
    224            }
    225            return buffer.toString();
    226        }
    227
    228        //-----------------------------------------------------------------------
    229        /**
    230         * <p>Converts all the whitespace separated words in a String into capitalized words,
    231         * that is each word is made up of a titlecase character and then a series of
    232         * lowercase characters.  </p>
    233         *
    234         * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.
    235         * A <code>null</code> input String returns <code>null</code>.
    236         * Capitalization uses the unicode title case, normally equivalent to
    237         * upper case.</p>
    238         *
    239         * <pre>
    240         * WordUtils.capitalizeFully(null)        = null
    241         * WordUtils.capitalizeFully("")          = ""
    242         * WordUtils.capitalizeFully("i am FINE") = "I Am Fine"
    243         * </pre>
    244         *
    245         * @param str  the String to capitalize, may be null
    246         * @return capitalized String, <code>null</code> if null String input
    247         */
    248        public static String capitalizeFully(String str) {
    249            return capitalizeFully(str, null);
    250        }
    251
    252        /**
    253         * <p>Converts all the delimiter separated words in a String into capitalized words,
    254         * that is each word is made up of a titlecase character and then a series of
    255         * lowercase characters. </p>
    256         *
    257         * <p>The delimiters represent a set of characters understood to separate words.
    258         * The first string character and the first non-delimiter character after a
    259         * delimiter will be capitalized. </p>
    260         *
    261         * <p>A <code>null</code> input String returns <code>null</code>.
    262         * Capitalization uses the unicode title case, normally equivalent to
    263         * upper case.</p>
    264         *
    265         * <pre>
    266         * WordUtils.capitalizeFully(null, *)            = null
    267         * WordUtils.capitalizeFully("", *)              = ""
    268         * WordUtils.capitalizeFully(*, null)            = *
    269         * WordUtils.capitalizeFully(*, new char[0])     = *
    270         * WordUtils.capitalizeFully("i aM.fine", {'.'}) = "I am.Fine"
    271         * </pre>
    272         *
    273         * @param str  the String to capitalize, may be null
    274         * @param delimiters  set of characters to determine capitalization, null means whitespace
    275         * @return capitalized String, <code>null</code> if null String input
    276         * @since 2.1
    277         */
    278        public static String capitalizeFully(String str, char... delimiters) {
    279            int delimLen = (delimiters == null ? -1 : delimiters.length);
    280            if (str == null || str.length() == 0 || delimLen == 0) {
    281                return str;
    282            }
    283            str = str.toLowerCase();
    284            return capitalize(str, delimiters);
    285        }
    286
    287        //-----------------------------------------------------------------------
    288        /**
    289         * <p>Uncapitalizes all the whitespace separated words in a String.
    290         * Only the first letter of each word is changed.</p>
    291         *
    292         * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.
    293         * A <code>null</code> input String returns <code>null</code>.</p>
    294         *
    295         * <pre>
    296         * WordUtils.uncapitalize(null)        = null
    297         * WordUtils.uncapitalize("")          = ""
    298         * WordUtils.uncapitalize("I Am FINE") = "i am fINE"
    299         * </pre>
    300         *
    301         * @param str  the String to uncapitalize, may be null
    302         * @return uncapitalized String, <code>null</code> if null String input
    303         * @see #capitalize(String)
    304         */
    305        public static String uncapitalize(String str) {
    306            return uncapitalize(str, null);
    307        }
    308
    309        /**
    310         * <p>Uncapitalizes all the whitespace separated words in a String.
    311         * Only the first letter of each word is changed.</p>
    312         *
    313         * <p>The delimiters represent a set of characters understood to separate words.
    314         * The first string character and the first non-delimiter character after a
    315         * delimiter will be uncapitalized. </p>
    316         *
    317         * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.
    318         * A <code>null</code> input String returns <code>null</code>.</p>
    319         *
    320         * <pre>
    321         * WordUtils.uncapitalize(null, *)            = null
    322         * WordUtils.uncapitalize("", *)              = ""
    323         * WordUtils.uncapitalize(*, null)            = *
    324         * WordUtils.uncapitalize(*, new char[0])     = *
    325         * WordUtils.uncapitalize("I AM.FINE", {'.'}) = "i AM.fINE"
    326         * </pre>
    327         *
    328         * @param str  the String to uncapitalize, may be null
    329         * @param delimiters  set of characters to determine uncapitalization, null means whitespace
    330         * @return uncapitalized String, <code>null</code> if null String input
    331         * @see #capitalize(String)
    332         * @since 2.1
    333         */
    334        public static String uncapitalize(String str, char... delimiters) {
    335            int delimLen = (delimiters == null ? -1 : delimiters.length);
    336            if (str == null || str.length() == 0 || delimLen == 0) {
    337                return str;
    338            }
    339            int strLen = str.length();
    340            StringBuilder buffer = new StringBuilder(strLen);
    341            boolean uncapitalizeNext = true;
    342            for (int i = 0; i < strLen; i++) {
    343                char ch = str.charAt(i);
    344
    345                if (isDelimiter(ch, delimiters)) {
    346                    buffer.append(ch);
    347                    uncapitalizeNext = true;
    348                } else if (uncapitalizeNext) {
    349                    buffer.append(Character.toLowerCase(ch));
    350                    uncapitalizeNext = false;
    351                } else {
    352                    buffer.append(ch);
    353                }
    354            }
    355            return buffer.toString();
    356        }
    357
    358        //-----------------------------------------------------------------------
    359        /**
    360         * <p>Swaps the case of a String using a word based algorithm.</p>
    361         *
    362         * <ul>
    363         *  <li>Upper case character converts to Lower case</li>
    364         *  <li>Title case character converts to Lower case</li>
    365         *  <li>Lower case character after Whitespace or at start converts to Title case</li>
    366         *  <li>Other Lower case character converts to Upper case</li>
    367         * </ul>
    368         *
    369         * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.
    370         * A <code>null</code> input String returns <code>null</code>.</p>
    371         *
    372         * <pre>
    373         * StringUtils.swapCase(null)                 = null
    374         * StringUtils.swapCase("")                   = ""
    375         * StringUtils.swapCase("The dog has a BONE") = "tHE DOG HAS A bone"
    376         * </pre>
    377         *
    378         * @param str  the String to swap case, may be null
    379         * @return the changed String, <code>null</code> if null String input
    380         */
    381        public static String swapCase(String str) {
    382            int strLen;
    383            if (str == null || (strLen = str.length()) == 0) {
    384                return str;
    385            }
    386            StringBuilder buffer = new StringBuilder(strLen);
    387
    388            boolean whitespace = true;
    389            char ch = 0;
    390            char tmp = 0;
    391
    392            for (int i = 0; i < strLen; i++) {
    393                ch = str.charAt(i);
    394                if (Character.isUpperCase(ch)) {
    395                    tmp = Character.toLowerCase(ch);
    396                } else if (Character.isTitleCase(ch)) {
    397                    tmp = Character.toLowerCase(ch);
    398                } else if (Character.isLowerCase(ch)) {
    399                    if (whitespace) {
    400                        tmp = Character.toTitleCase(ch);
    401                    } else {
    402                        tmp = Character.toUpperCase(ch);
    403                    }
    404                } else {
    405                    tmp = ch;
    406                }
    407                buffer.append(tmp);
    408                whitespace = Character.isWhitespace(ch);
    409            }
    410            return buffer.toString();
    411        }
    412
    413        //-----------------------------------------------------------------------
    414        /**
    415         * <p>Extracts the initial letters from each word in the String.</p>
    416         *
    417         * <p>The first letter of the string and all first letters after
    418         * whitespace are returned as a new string.
    419         * Their case is not changed.</p>
    420         *
    421         * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.
    422         * A <code>null</code> input String returns <code>null</code>.</p>
    423         *
    424         * <pre>
    425         * WordUtils.initials(null)             = null
    426         * WordUtils.initials("")               = ""
    427         * WordUtils.initials("Ben John Lee")   = "BJL"
    428         * WordUtils.initials("Ben J.Lee")      = "BJ"
    429         * </pre>
    430         *
    431         * @param str  the String to get initials from, may be null
    432         * @return String of initial letters, <code>null</code> if null String input
    433         * @see #initials(String,char[])
    434         * @since 2.2
    435         */
    436        public static String initials(String str) {
    437            return initials(str, null);
    438        }
    439
    440        /**
    441         * <p>Extracts the initial letters from each word in the String.</p>
    442         *
    443         * <p>The first letter of the string and all first letters after the
    444         * defined delimiters are returned as a new string.
    445         * Their case is not changed.</p>
    446         *
    447         * <p>If the delimiters array is null, then Whitespace is used.
    448         * Whitespace is defined by {@link Character#isWhitespace(char)}.
    449         * A <code>null</code> input String returns <code>null</code>.
    450         * An empty delimiter array returns an empty String.</p>
    451         *
    452         * <pre>
    453         * WordUtils.initials(null, *)                = null
    454         * WordUtils.initials("", *)                  = ""
    455         * WordUtils.initials("Ben John Lee", null)   = "BJL"
    456         * WordUtils.initials("Ben J.Lee", null)      = "BJ"
    457         * WordUtils.initials("Ben J.Lee", [' ','.']) = "BJL"
    458         * WordUtils.initials(*, new char[0])         = ""
    459         * </pre>
    460         *
    461         * @param str  the String to get initials from, may be null
    462         * @param delimiters  set of characters to determine words, null means whitespace
    463         * @return String of initial letters, <code>null</code> if null String input
    464         * @see #initials(String)
    465         * @since 2.2
    466         */
    467        public static String initials(String str, char... delimiters) {
    468            if (str == null || str.length() == 0) {
    469                return str;
    470            }
    471            if (delimiters != null && delimiters.length == 0) {
    472                return "";
    473            }
    474            int strLen = str.length();
    475            char[] buf = new char[strLen / 2 + 1];
    476            int count = 0;
    477            boolean lastWasGap = true;
    478            for (int i = 0; i < strLen; i++) {
    479                char ch = str.charAt(i);
    480
    481                if (isDelimiter(ch, delimiters)) {
    482                    lastWasGap = true;
    483                } else if (lastWasGap) {
    484                    buf[count++] = ch;
    485                    lastWasGap = false;
    486                } else {
    487                    // ignore ch
    488                }
    489            }
    490            return new String(buf, 0, count);
    491        }
    492
    493        //-----------------------------------------------------------------------
    494        /**
    495         * Is the character a delimiter.
    496         *
    497         * @param ch  the character to check
    498         * @param delimiters  the delimiters
    499         * @return true if it is a delimiter
    500         */
    501        private static boolean isDelimiter(char ch, char[] delimiters) {
    502            if (delimiters == null) {
    503                return Character.isWhitespace(ch);
    504            }
    505            for (int i = 0, isize = delimiters.length; i < isize; i++) {
    506                if (ch == delimiters[i]) {
    507                    return true;
    508                }
    509            }
    510            return false;
    511        }
    512
    513        //-----------------------------------------------------------------------
    514        /**
    515         * Abbreviates a string nicely.
    516         *
    517         * This method searches for the first space after the lower limit and abbreviates
    518         * the String there. It will also append any String passed as a parameter
    519         * to the end of the String. The upper limit can be specified to forcibly
    520         * abbreviate a String.
    521         *
    522         * @param str         the string to be abbreviated. If null is passed, null is returned.
    523         *                    If the empty String is passed, the empty string is returned.
    524         * @param lower       the lower limit.
    525         * @param upper       the upper limit; specify -1 if no limit is desired.
    526         *                    If the upper limit is lower than the lower limit, it will be
    527         *                    adjusted to be the same as the lower limit.
    528         * @param appendToEnd String to be appended to the end of the abbreviated string.
    529         *                    This is appended ONLY if the string was indeed abbreviated.
    530         *                    The append does not count towards the lower or upper limits.
    531         * @return the abbreviated String.
    532         * @since 2.4
    533         */
    534        public static String abbreviate(String str, int lower, int upper, String appendToEnd) {
    535            // initial parameter checks
    536            if (str == null) {
    537                return null;
    538            }
    539            if (str.length() == 0) {
    540                return StringUtils.EMPTY;
    541            }
    542
    543            // if the lower value is greater than the length of the string,
    544            // set to the length of the string
    545            if (lower > str.length()) {
    546                lower = str.length();
    547            }
    548            // if the upper value is -1 (i.e. no limit) or is greater
    549            // than the length of the string, set to the length of the string
    550            if (upper == -1 || upper > str.length()) {
    551                upper = str.length();
    552            }
    553            // if upper is less than lower, raise it to lower
    554            if (upper < lower) {
    555                upper = lower;
    556            }
    557
    558            StringBuilder result = new StringBuilder();
    559            int index = StringUtils.indexOf(str, " ", lower);
    560            if (index == -1) {
    561                result.append(str.substring(0, upper));
    562                // only if abbreviation has occured do we append the appendToEnd value
    563                if (upper != str.length()) {
    564                    result.append(StringUtils.defaultString(appendToEnd));
    565                }
    566            } else if (index > upper) {
    567                result.append(str.substring(0, upper));
    568                result.append(StringUtils.defaultString(appendToEnd));
    569            } else {
    570                result.append(str.substring(0, index));
    571                result.append(StringUtils.defaultString(appendToEnd));
    572            }
    573            return result.toString();
    574        }
    575
    576    }