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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    * 
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   * 
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.commons.lang3.text;
18  
19  import java.util.regex.Matcher;
20  import java.util.regex.Pattern;
21  
22  import org.apache.commons.lang3.ArrayUtils;
23  import org.apache.commons.lang3.StringUtils;
24  import org.apache.commons.lang3.SystemUtils;
25  
26  /**
27   * <p>Operations on Strings that contain words.</p>
28   * 
29   * <p>This class tries to handle <code>null</code> input gracefully.
30   * An exception will not be thrown for a <code>null</code> input.
31   * Each method documents its behaviour in more detail.</p>
32   * 
33   * @since 2.0
34   */
35  public class WordUtils {
36  
37      /**
38       * <p><code>WordUtils</code> instances should NOT be constructed in
39       * standard programming. Instead, the class should be used as
40       * <code>WordUtils.wrap("foo bar", 20);</code>.</p>
41       *
42       * <p>This constructor is public to permit tools that require a JavaBean
43       * instance to operate.</p>
44       */
45      public WordUtils() {
46        super();
47      }
48  
49      // Wrapping
50      //--------------------------------------------------------------------------
51      /**
52       * <p>Wraps a single line of text, identifying words by <code>' '</code>.</p>
53       * 
54       * <p>New lines will be separated by the system property line separator.
55       * Very long words, such as URLs will <i>not</i> be wrapped.</p>
56       * 
57       * <p>Leading spaces on a new line are stripped.
58       * Trailing spaces are not stripped.</p>
59       *
60       * <table border="1" summary="Wrap Results">
61       *  <tr>
62       *   <th>input</th>
63       *   <th>wrapLength</th>
64       *   <th>result</th>
65       *  </tr>
66       *  <tr>
67       *   <td>null</td>
68       *   <td>*</td>
69       *   <td>null</td>
70       *  </tr>
71       *  <tr>
72       *   <td>""</td>
73       *   <td>*</td>
74       *   <td>""</td>
75       *  </tr>
76       *  <tr>
77       *   <td>"Here is one line of text that is going to be wrapped after 20 columns."</td>
78       *   <td>20</td>
79       *   <td>"Here is one line of\ntext that is going\nto be wrapped after\n20 columns."</td>
80       *  </tr>
81       *  <tr>
82       *   <td>"Click here to jump to the commons website - http://commons.apache.org"</td>
83       *   <td>20</td>
84       *   <td>"Click here to jump\nto the commons\nwebsite -\nhttp://commons.apache.org"</td>
85       *  </tr>
86       *  <tr>
87       *   <td>"Click here, http://commons.apache.org, to jump to the commons website"</td>
88       *   <td>20</td>
89       *   <td>"Click here,\nhttp://commons.apache.org,\nto jump to the\ncommons website"</td>
90       *  </tr>
91       * </table>
92       *
93       * (assuming that '\n' is the systems line separator)
94       *
95       * @param str  the String to be word wrapped, may be null
96       * @param wrapLength  the column to wrap the words at, less than 1 is treated as 1
97       * @return a line with newlines inserted, <code>null</code> if null input
98       */
99      public static String wrap(final String str, final int wrapLength) {
100         return wrap(str, wrapLength, null, false);
101     }
102     
103     /**
104      * <p>Wraps a single line of text, identifying words by <code>' '</code>.</p>
105      * 
106      * <p>Leading spaces on a new line are stripped.
107      * Trailing spaces are not stripped.</p>
108      *
109      * <table border="1" summary="Wrap Results">
110      *  <tr>
111      *   <th>input</th>
112      *   <th>wrapLenght</th>
113      *   <th>newLineString</th>
114      *   <th>wrapLongWords</th>
115      *   <th>result</th>
116      *  </tr>
117      *  <tr>
118      *   <td>null</td>
119      *   <td>*</td>
120      *   <td>*</td>
121      *   <td>true/false</td>
122      *   <td>null</td>
123      *  </tr>
124      *  <tr>
125      *   <td>""</td>
126      *   <td>*</td>
127      *   <td>*</td>
128      *   <td>true/false</td>
129      *   <td>""</td>
130      *  </tr>
131      *  <tr>
132      *   <td>"Here is one line of text that is going to be wrapped after 20 columns."</td>
133      *   <td>20</td>
134      *   <td>"\n"</td>
135      *   <td>true/false</td>
136      *   <td>"Here is one line of\ntext that is going\nto be wrapped after\n20 columns."</td>
137      *  </tr>
138      *  <tr>
139      *   <td>"Here is one line of text that is going to be wrapped after 20 columns."</td>
140      *   <td>20</td>
141      *   <td>"&lt;br /&gt;"</td>
142      *   <td>true/false</td>
143      *   <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>
144      *  </tr>
145      *  <tr>
146      *   <td>"Here is one line of text that is going to be wrapped after 20 columns."</td>
147      *   <td>20</td>
148      *   <td>null</td>
149      *   <td>true/false</td>
150      *   <td>"Here is one line of" + systemNewLine + "text that is going" + systemNewLine + "to be wrapped after" + systemNewLine + "20 columns."</td>
151      *  </tr>
152      *  <tr>
153      *   <td>"Click here to jump to the commons website - http://commons.apache.org"</td>
154      *   <td>20</td>
155      *   <td>"\n"</td>
156      *   <td>false</td>
157      *   <td>"Click here to jump\nto the commons\nwebsite -\nhttp://commons.apache.org"</td>
158      *  </tr>
159      *  <tr>
160      *   <td>"Click here to jump to the commons website - http://commons.apache.org"</td>
161      *   <td>20</td>
162      *   <td>"\n"</td>
163      *   <td>true</td>
164      *   <td>"Click here to jump\nto the commons\nwebsite -\nhttp://commons.apach\ne.org"</td>
165      *  </tr>
166      * </table>
167      *
168      * @param str  the String to be word wrapped, may be null
169      * @param wrapLength  the column to wrap the words at, less than 1 is treated as 1
170      * @param newLineStr  the string to insert for a new line, 
171      *  <code>null</code> uses the system property line separator
172      * @param wrapLongWords  true if long words (such as URLs) should be wrapped
173      * @return a line with newlines inserted, <code>null</code> if null input
174      */
175     public static String wrap(final String str, int wrapLength, String newLineStr, final boolean wrapLongWords) {
176         return wrap(str, wrapLength, newLineStr, wrapLongWords, " ");
177     }
178 
179     /**
180      * <p>Wraps a single line of text, identifying words by <code>wrapOn</code>.</p>
181      *
182      * <p>Leading spaces on a new line are stripped.
183      * Trailing spaces are not stripped.</p>
184      *
185      * <table border="1" summary="Wrap Results">
186      *  <tr>
187      *   <th>input</th>
188      *   <th>wrapLenght</th>
189      *   <th>newLineString</th>
190      *   <th>wrapLongWords</th>
191      *   <th>wrapOn</th>
192      *   <th>result</th>
193      *  </tr>
194      *  <tr>
195      *   <td>null</td>
196      *   <td>*</td>
197      *   <td>*</td>
198      *   <td>true/false</td>
199      *   <td>*</td>
200      *   <td>null</td>
201      *  </tr>
202      *  <tr>
203      *   <td>""</td>
204      *   <td>*</td>
205      *   <td>*</td>
206      *   <td>true/false</td>
207      *   <td>*</td>
208      *   <td>""</td>
209      *  </tr>
210      *  <tr>
211      *   <td>"Here is one line of text that is going to be wrapped after 20 columns."</td>
212      *   <td>20</td>
213      *   <td>"\n"</td>
214      *   <td>true/false</td>
215      *   <td>" "</td>
216      *   <td>"Here is one line of\ntext that is going\nto be wrapped after\n20 columns."</td>
217      *  </tr>
218      *  <tr>
219      *   <td>"Here is one line of text that is going to be wrapped after 20 columns."</td>
220      *   <td>20</td>
221      *   <td>"&lt;br /&gt;"</td>
222      *   <td>true/false</td>
223      *   <td>" "</td>
224      *   <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>
225      *  </tr>
226      *  <tr>
227      *   <td>"Here is one line of text that is going to be wrapped after 20 columns."</td>
228      *   <td>20</td>
229      *   <td>null</td>
230      *   <td>true/false</td>
231      *   <td>" "</td>
232      *   <td>"Here is one line of" + systemNewLine + "text that is going" + systemNewLine + "to be wrapped after" + systemNewLine + "20 columns."</td>
233      *  </tr>
234      *  <tr>
235      *   <td>"Click here to jump to the commons website - http://commons.apache.org"</td>
236      *   <td>20</td>
237      *   <td>"\n"</td>
238      *   <td>false</td>
239      *   <td>" "</td>
240      *   <td>"Click here to jump\nto the commons\nwebsite -\nhttp://commons.apache.org"</td>
241      *  </tr>
242      *  <tr>
243      *   <td>"Click here to jump to the commons website - http://commons.apache.org"</td>
244      *   <td>20</td>
245      *   <td>"\n"</td>
246      *   <td>true</td>
247      *   <td>" "</td>
248      *   <td>"Click here to jump\nto the commons\nwebsite -\nhttp://commons.apach\ne.org"</td>
249      *  </tr>
250      *  <tr>
251      *   <td>"flammable/inflammable"</td>
252      *   <td>20</td>
253      *   <td>"\n"</td>
254      *   <td>true</td>
255      *   <td>"/"</td>
256      *   <td>"flammable\ninflammable"</td>
257      *  </tr>
258      * </table>
259      * @param str  the String to be word wrapped, may be null
260      * @param wrapLength  the column to wrap the words at, less than 1 is treated as 1
261      * @param newLineStr  the string to insert for a new line,
262      *  <code>null</code> uses the system property line separator
263      * @param wrapLongWords  true if long words (such as URLs) should be wrapped
264      * @param wrapOn regex expression to be used as a breakable characters,
265      *               if blank string is provided a space character will be used
266      * @return a line with newlines inserted, <code>null</code> if null input
267      */
268     public static String wrap(final String str, int wrapLength, String newLineStr, final boolean wrapLongWords, String wrapOn) {
269         if (str == null) {
270             return null;
271         }
272         if (newLineStr == null) {
273             newLineStr = SystemUtils.LINE_SEPARATOR;
274         }
275         if (wrapLength < 1) {
276             wrapLength = 1;
277         }
278         if (StringUtils.isBlank(wrapOn)) {
279             wrapOn = " ";
280         }
281         Pattern patternToWrapOn = Pattern.compile(wrapOn);
282         final int inputLineLength = str.length();
283         int offset = 0;
284         final StringBuilder wrappedLine = new StringBuilder(inputLineLength + 32);
285 
286         while (offset < inputLineLength) {
287             int spaceToWrapAt = -1;
288             Matcher matcher = patternToWrapOn.matcher(str.substring(offset, Math.min(offset + wrapLength + 1, inputLineLength)));
289             if (matcher.find()) {
290                 if (matcher.start() == 0) {
291                     offset += matcher.end();
292                     continue;
293                 }else {
294                     spaceToWrapAt = matcher.start();
295                 }
296             }
297 
298             // only last line without leading spaces is left
299             if(inputLineLength - offset <= wrapLength) {
300                 break;
301             }
302 
303             while(matcher.find()){
304                 spaceToWrapAt = matcher.start() + offset;
305             }
306 
307             if (spaceToWrapAt >= offset) {
308                 // normal case
309                 wrappedLine.append(str.substring(offset, spaceToWrapAt));
310                 wrappedLine.append(newLineStr);
311                 offset = spaceToWrapAt + 1;
312 
313             } else {
314                 // really long word or URL
315                 if (wrapLongWords) {
316                     // wrap really long word one line at a time
317                     wrappedLine.append(str.substring(offset, wrapLength + offset));
318                     wrappedLine.append(newLineStr);
319                     offset += wrapLength;
320                 } else {
321                     // do not wrap really long word, just extend beyond limit
322                     matcher = patternToWrapOn.matcher(str.substring(offset + wrapLength));
323                     if (matcher.find()) {
324                         spaceToWrapAt = matcher.start() + offset + wrapLength;
325                     }
326 
327                     if (spaceToWrapAt >= 0) {
328                         wrappedLine.append(str.substring(offset, spaceToWrapAt));
329                         wrappedLine.append(newLineStr);
330                         offset = spaceToWrapAt + 1;
331                     } else {
332                         wrappedLine.append(str.substring(offset));
333                         offset = inputLineLength;
334                     }
335                 }
336             }
337         }
338 
339         // Whatever is left in line is short enough to just pass through
340         wrappedLine.append(str.substring(offset));
341 
342         return wrappedLine.toString();
343     }
344 
345     // Capitalizing
346     //-----------------------------------------------------------------------
347     /**
348      * <p>Capitalizes all the whitespace separated words in a String.
349      * Only the first character of each word is changed. To convert the 
350      * rest of each word to lowercase at the same time, 
351      * use {@link #capitalizeFully(String)}.</p>
352      *
353      * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.
354      * A <code>null</code> input String returns <code>null</code>.
355      * Capitalization uses the Unicode title case, normally equivalent to
356      * upper case.</p>
357      *
358      * <pre>
359      * WordUtils.capitalize(null)        = null
360      * WordUtils.capitalize("")          = ""
361      * WordUtils.capitalize("i am FINE") = "I Am FINE"
362      * </pre>
363      * 
364      * @param str  the String to capitalize, may be null
365      * @return capitalized String, <code>null</code> if null String input
366      * @see #uncapitalize(String)
367      * @see #capitalizeFully(String)
368      */
369     public static String capitalize(final String str) {
370         return capitalize(str, null);
371     }
372 
373     /**
374      * <p>Capitalizes all the delimiter separated words in a String.
375      * Only the first character of each word is changed. To convert the 
376      * rest of each word to lowercase at the same time, 
377      * use {@link #capitalizeFully(String, char[])}.</p>
378      *
379      * <p>The delimiters represent a set of characters understood to separate words.
380      * The first string character and the first non-delimiter character after a
381      * delimiter will be capitalized. </p>
382      *
383      * <p>A <code>null</code> input String returns <code>null</code>.
384      * Capitalization uses the Unicode title case, normally equivalent to
385      * upper case.</p>
386      *
387      * <pre>
388      * WordUtils.capitalize(null, *)            = null
389      * WordUtils.capitalize("", *)              = ""
390      * WordUtils.capitalize(*, new char[0])     = *
391      * WordUtils.capitalize("i am fine", null)  = "I Am Fine"
392      * WordUtils.capitalize("i aM.fine", {'.'}) = "I aM.Fine"
393      * </pre>
394      * 
395      * @param str  the String to capitalize, may be null
396      * @param delimiters  set of characters to determine capitalization, null means whitespace
397      * @return capitalized String, <code>null</code> if null String input
398      * @see #uncapitalize(String)
399      * @see #capitalizeFully(String)
400      * @since 2.1
401      */
402     public static String capitalize(final String str, final char... delimiters) {
403         final int delimLen = delimiters == null ? -1 : delimiters.length;
404         if (StringUtils.isEmpty(str) || delimLen == 0) {
405             return str;
406         }
407         final char[] buffer = str.toCharArray();
408         boolean capitalizeNext = true;
409         for (int i = 0; i < buffer.length; i++) {
410             final char ch = buffer[i];
411             if (isDelimiter(ch, delimiters)) {
412                 capitalizeNext = true;
413             } else if (capitalizeNext) {
414                 buffer[i] = Character.toTitleCase(ch);
415                 capitalizeNext = false;
416             }
417         }
418         return new String(buffer);
419     }
420 
421     //-----------------------------------------------------------------------
422     /**
423      * <p>Converts all the whitespace separated words in a String into capitalized words, 
424      * that is each word is made up of a titlecase character and then a series of 
425      * lowercase characters.  </p>
426      *
427      * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.
428      * A <code>null</code> input String returns <code>null</code>.
429      * Capitalization uses the Unicode title case, normally equivalent to
430      * upper case.</p>
431      *
432      * <pre>
433      * WordUtils.capitalizeFully(null)        = null
434      * WordUtils.capitalizeFully("")          = ""
435      * WordUtils.capitalizeFully("i am FINE") = "I Am Fine"
436      * </pre>
437      * 
438      * @param str  the String to capitalize, may be null
439      * @return capitalized String, <code>null</code> if null String input
440      */
441     public static String capitalizeFully(final String str) {
442         return capitalizeFully(str, null);
443     }
444 
445     /**
446      * <p>Converts all the delimiter separated words in a String into capitalized words, 
447      * that is each word is made up of a titlecase character and then a series of 
448      * lowercase characters. </p>
449      *
450      * <p>The delimiters represent a set of characters understood to separate words.
451      * The first string character and the first non-delimiter character after a
452      * delimiter will be capitalized. </p>
453      *
454      * <p>A <code>null</code> input String returns <code>null</code>.
455      * Capitalization uses the Unicode title case, normally equivalent to
456      * upper case.</p>
457      *
458      * <pre>
459      * WordUtils.capitalizeFully(null, *)            = null
460      * WordUtils.capitalizeFully("", *)              = ""
461      * WordUtils.capitalizeFully(*, null)            = *
462      * WordUtils.capitalizeFully(*, new char[0])     = *
463      * WordUtils.capitalizeFully("i aM.fine", {'.'}) = "I am.Fine"
464      * </pre>
465      * 
466      * @param str  the String to capitalize, may be null
467      * @param delimiters  set of characters to determine capitalization, null means whitespace
468      * @return capitalized String, <code>null</code> if null String input
469      * @since 2.1
470      */
471     public static String capitalizeFully(String str, final char... delimiters) {
472         final int delimLen = delimiters == null ? -1 : delimiters.length;
473         if (StringUtils.isEmpty(str) || delimLen == 0) {
474             return str;
475         }
476         str = str.toLowerCase();
477         return capitalize(str, delimiters);
478     }
479 
480     //-----------------------------------------------------------------------
481     /**
482      * <p>Uncapitalizes all the whitespace separated words in a String.
483      * Only the first character of each word is changed.</p>
484      *
485      * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.
486      * A <code>null</code> input String returns <code>null</code>.</p>
487      *
488      * <pre>
489      * WordUtils.uncapitalize(null)        = null
490      * WordUtils.uncapitalize("")          = ""
491      * WordUtils.uncapitalize("I Am FINE") = "i am fINE"
492      * </pre>
493      * 
494      * @param str  the String to uncapitalize, may be null
495      * @return uncapitalized String, <code>null</code> if null String input
496      * @see #capitalize(String)
497      */
498     public static String uncapitalize(final String str) {
499         return uncapitalize(str, null);
500     }
501 
502     /**
503      * <p>Uncapitalizes all the whitespace separated words in a String.
504      * Only the first character of each word is changed.</p>
505      *
506      * <p>The delimiters represent a set of characters understood to separate words.
507      * The first string character and the first non-delimiter character after a
508      * delimiter will be uncapitalized. </p>
509      *
510      * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.
511      * A <code>null</code> input String returns <code>null</code>.</p>
512      *
513      * <pre>
514      * WordUtils.uncapitalize(null, *)            = null
515      * WordUtils.uncapitalize("", *)              = ""
516      * WordUtils.uncapitalize(*, null)            = *
517      * WordUtils.uncapitalize(*, new char[0])     = *
518      * WordUtils.uncapitalize("I AM.FINE", {'.'}) = "i AM.fINE"
519      * </pre>
520      * 
521      * @param str  the String to uncapitalize, may be null
522      * @param delimiters  set of characters to determine uncapitalization, null means whitespace
523      * @return uncapitalized String, <code>null</code> if null String input
524      * @see #capitalize(String)
525      * @since 2.1
526      */
527     public static String uncapitalize(final String str, final char... delimiters) {
528         final int delimLen = delimiters == null ? -1 : delimiters.length;
529         if (StringUtils.isEmpty(str) || delimLen == 0) {
530             return str;
531         }
532         final char[] buffer = str.toCharArray();
533         boolean uncapitalizeNext = true;
534         for (int i = 0; i < buffer.length; i++) {
535             final char ch = buffer[i];
536             if (isDelimiter(ch, delimiters)) {
537                 uncapitalizeNext = true;
538             } else if (uncapitalizeNext) {
539                 buffer[i] = Character.toLowerCase(ch);
540                 uncapitalizeNext = false;
541             }
542         }
543         return new String(buffer);
544     }
545 
546     //-----------------------------------------------------------------------
547     /**
548      * <p>Swaps the case of a String using a word based algorithm.</p>
549      * 
550      * <ul>
551      *  <li>Upper case character converts to Lower case</li>
552      *  <li>Title case character converts to Lower case</li>
553      *  <li>Lower case character after Whitespace or at start converts to Title case</li>
554      *  <li>Other Lower case character converts to Upper case</li>
555      * </ul>
556      * 
557      * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.
558      * A <code>null</code> input String returns <code>null</code>.</p>
559      * 
560      * <pre>
561      * StringUtils.swapCase(null)                 = null
562      * StringUtils.swapCase("")                   = ""
563      * StringUtils.swapCase("The dog has a BONE") = "tHE DOG HAS A bone"
564      * </pre>
565      * 
566      * @param str  the String to swap case, may be null
567      * @return the changed String, <code>null</code> if null String input
568      */
569     public static String swapCase(final String str) {
570         if (StringUtils.isEmpty(str)) {
571             return str;
572         }
573         final char[] buffer = str.toCharArray();
574 
575         boolean whitespace = true;
576 
577         for (int i = 0; i < buffer.length; i++) {
578             final char ch = buffer[i];
579             if (Character.isUpperCase(ch)) {
580                 buffer[i] = Character.toLowerCase(ch);
581                 whitespace = false;
582             } else if (Character.isTitleCase(ch)) {
583                 buffer[i] = Character.toLowerCase(ch);
584                 whitespace = false;
585             } else if (Character.isLowerCase(ch)) {
586                 if (whitespace) {
587                     buffer[i] = Character.toTitleCase(ch);
588                     whitespace = false;
589                 } else {
590                     buffer[i] = Character.toUpperCase(ch);
591                 }
592             } else {
593                 whitespace = Character.isWhitespace(ch);
594             }
595         }
596         return new String(buffer);
597     }
598 
599     //-----------------------------------------------------------------------
600     /**
601      * <p>Extracts the initial characters from each word in the String.</p>
602      * 
603      * <p>All first characters after whitespace are returned as a new string.
604      * Their case is not changed.</p>
605      *
606      * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.
607      * A <code>null</code> input String returns <code>null</code>.</p>
608      *
609      * <pre>
610      * WordUtils.initials(null)             = null
611      * WordUtils.initials("")               = ""
612      * WordUtils.initials("Ben John Lee")   = "BJL"
613      * WordUtils.initials("Ben J.Lee")      = "BJ"
614      * </pre>
615      *
616      * @param str  the String to get initials from, may be null
617      * @return String of initial letters, <code>null</code> if null String input
618      * @see #initials(String,char[])
619      * @since 2.2
620      */
621     public static String initials(final String str) {
622         return initials(str, null);
623     }
624 
625     /**
626      * <p>Extracts the initial characters from each word in the String.</p>
627      * 
628      * <p>All first characters after the defined delimiters are returned as a new string.
629      * Their case is not changed.</p>
630      *
631      * <p>If the delimiters array is null, then Whitespace is used.
632      * Whitespace is defined by {@link Character#isWhitespace(char)}.
633      * A <code>null</code> input String returns <code>null</code>.
634      * An empty delimiter array returns an empty String.</p>
635      *
636      * <pre>
637      * WordUtils.initials(null, *)                = null
638      * WordUtils.initials("", *)                  = ""
639      * WordUtils.initials("Ben John Lee", null)   = "BJL"
640      * WordUtils.initials("Ben J.Lee", null)      = "BJ"
641      * WordUtils.initials("Ben J.Lee", [' ','.']) = "BJL"
642      * WordUtils.initials(*, new char[0])         = ""
643      * </pre>
644      * 
645      * @param str  the String to get initials from, may be null
646      * @param delimiters  set of characters to determine words, null means whitespace
647      * @return String of initial characters, <code>null</code> if null String input
648      * @see #initials(String)
649      * @since 2.2
650      */
651     public static String initials(final String str, final char... delimiters) {
652         if (StringUtils.isEmpty(str)) {
653             return str;
654         }
655         if (delimiters != null && delimiters.length == 0) {
656             return StringUtils.EMPTY;
657         }
658         final int strLen = str.length();
659         final char[] buf = new char[strLen / 2 + 1];
660         int count = 0;
661         boolean lastWasGap = true;
662         for (int i = 0; i < strLen; i++) {
663             final char ch = str.charAt(i);
664 
665             if (isDelimiter(ch, delimiters)) {
666                 lastWasGap = true;
667             } else if (lastWasGap) {
668                 buf[count++] = ch;
669                 lastWasGap = false;
670             } else {
671                 continue; // ignore ch
672             }
673         }
674         return new String(buf, 0, count);
675     }
676 
677     //-----------------------------------------------------------------------
678     /**
679      * <p>Checks if the String contains all words in the given array.</p>
680      *
681      * <p>
682      * A {@code null} String will return {@code false}. A {@code null}, zero
683      * length search array or if one element of array is null will return {@code false}.
684      * </p>
685      *
686      * <pre>
687      * WordUtils.containsAllWords(null, *)            = false
688      * WordUtils.containsAllWords("", *)              = false
689      * WordUtils.containsAllWords(*, null)            = false
690      * WordUtils.containsAllWords(*, [])              = false
691      * WordUtils.containsAllWords("abcd", "ab", "cd") = false
692      * WordUtils.containsAllWords("abc def", "def", "abc") = true
693      * </pre>
694      *
695      *
696      * @param word The CharSequence to check, may be null
697      * @param words The array of String words to search for, may be null
698      * @return {@code true} if all search words are found, {@code false} otherwise
699      * @since 3.5
700      */
701     public static boolean containsAllWords(CharSequence word, CharSequence... words) {
702         if (StringUtils.isEmpty(word) || ArrayUtils.isEmpty(words)) {
703             return false;
704         }
705         for (CharSequence w : words) {
706             if (StringUtils.isBlank(w)) {
707                 return false;
708             }
709             Pattern p = Pattern.compile(".*\\b" + w + "\\b.*");
710             if (!p.matcher(word).matches()) {
711                 return false;
712             }
713         }
714         return true;
715     }
716 
717     //-----------------------------------------------------------------------
718     /**
719      * Is the character a delimiter.
720      *
721      * @param ch  the character to check
722      * @param delimiters  the delimiters
723      * @return true if it is a delimiter
724      */
725     private static boolean isDelimiter(final char ch, final char[] delimiters) {
726         if (delimiters == null) {
727             return Character.isWhitespace(ch);
728         }
729         for (final char delimiter : delimiters) {
730             if (ch == delimiter) {
731                 return true;
732             }
733         }
734         return false;
735     }
736 
737 }