Coverage Report - org.apache.commons.lang3.text.WordUtils
 
Classes in this File Line Coverage Branch Coverage Complexity
WordUtils
100%
111/111
100%
76/76
4,615
 
 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 org.apache.commons.lang3.StringUtils;
 20  
 import org.apache.commons.lang3.SystemUtils;
 21  
 
 22  
 /**
 23  
  * <p>Operations on Strings that contain words.</p>
 24  
  * 
 25  
  * <p>This class tries to handle <code>null</code> input gracefully.
 26  
  * An exception will not be thrown for a <code>null</code> input.
 27  
  * Each method documents its behaviour in more detail.</p>
 28  
  * 
 29  
  * @since 2.0
 30  
  * @version $Id: WordUtils.java 1583482 2014-03-31 22:54:57Z niallp $
 31  
  */
 32  
 public class WordUtils {
 33  
 
 34  
     /**
 35  
      * <p><code>WordUtils</code> instances should NOT be constructed in
 36  
      * standard programming. Instead, the class should be used as
 37  
      * <code>WordUtils.wrap("foo bar", 20);</code>.</p>
 38  
      *
 39  
      * <p>This constructor is public to permit tools that require a JavaBean
 40  
      * instance to operate.</p>
 41  
      */
 42  
     public WordUtils() {
 43  1
       super();
 44  1
     }
 45  
 
 46  
     // Wrapping
 47  
     //--------------------------------------------------------------------------
 48  
     /**
 49  
      * <p>Wraps a single line of text, identifying words by <code>' '</code>.</p>
 50  
      * 
 51  
      * <p>New lines will be separated by the system property line separator.
 52  
      * Very long words, such as URLs will <i>not</i> be wrapped.</p>
 53  
      * 
 54  
      * <p>Leading spaces on a new line are stripped.
 55  
      * Trailing spaces are not stripped.</p>
 56  
      *
 57  
      * <table border="1" summary="Wrap Results">
 58  
      *  <tr>
 59  
      *   <th>input</th>
 60  
      *   <th>wrapLength</th>
 61  
      *   <th>result</th>
 62  
      *  </tr>
 63  
      *  <tr>
 64  
      *   <td>null</td>
 65  
      *   <td>*</td>
 66  
      *   <td>null</td>
 67  
      *  </tr>
 68  
      *  <tr>
 69  
      *   <td>""</td>
 70  
      *   <td>*</td>
 71  
      *   <td>""</td>
 72  
      *  </tr>
 73  
      *  <tr>
 74  
      *   <td>"Here is one line of text that is going to be wrapped after 20 columns."</td>
 75  
      *   <td>20</td>
 76  
      *   <td>"Here is one line of\ntext that is going\nto be wrapped after\n20 columns."</td>
 77  
      *  </tr>
 78  
      *  <tr>
 79  
      *   <td>"Click here to jump to the commons website - http://commons.apache.org"</td>
 80  
      *   <td>20</td>
 81  
      *   <td>"Click here to jump\nto the commons\nwebsite -\nhttp://commons.apache.org"</td>
 82  
      *  </tr>
 83  
      *  <tr>
 84  
      *   <td>"Click here, http://commons.apache.org, to jump to the commons website"</td>
 85  
      *   <td>20</td>
 86  
      *   <td>"Click here,\nhttp://commons.apache.org,\nto jump to the\ncommons website"</td>
 87  
      *  </tr>
 88  
      * </table>
 89  
      *
 90  
      * (assuming that '\n' is the systems line separator)
 91  
      *
 92  
      * @param str  the String to be word wrapped, may be null
 93  
      * @param wrapLength  the column to wrap the words at, less than 1 is treated as 1
 94  
      * @return a line with newlines inserted, <code>null</code> if null input
 95  
      */
 96  
     public static String wrap(final String str, final int wrapLength) {
 97  7
         return wrap(str, wrapLength, null, false);
 98  
     }
 99  
     
 100  
     /**
 101  
      * <p>Wraps a single line of text, identifying words by <code>' '</code>.</p>
 102  
      * 
 103  
      * <p>Leading spaces on a new line are stripped.
 104  
      * Trailing spaces are not stripped.</p>
 105  
      *
 106  
      * <table border="1" summary="Wrap Results">
 107  
      *  <tr>
 108  
      *   <th>input</th>
 109  
      *   <th>wrapLenght</th>
 110  
      *   <th>newLineString</th>
 111  
      *   <th>wrapLongWords</th>
 112  
      *   <th>result</th>
 113  
      *  </tr>
 114  
      *  <tr>
 115  
      *   <td>null</td>
 116  
      *   <td>*</td>
 117  
      *   <td>*</td>
 118  
      *   <td>true/false</td>
 119  
      *   <td>null</td>
 120  
      *  </tr>
 121  
      *  <tr>
 122  
      *   <td>""</td>
 123  
      *   <td>*</td>
 124  
      *   <td>*</td>
 125  
      *   <td>true/false</td>
 126  
      *   <td>""</td>
 127  
      *  </tr>
 128  
      *  <tr>
 129  
      *   <td>"Here is one line of text that is going to be wrapped after 20 columns."</td>
 130  
      *   <td>20</td>
 131  
      *   <td>"\n"</td>
 132  
      *   <td>true/false</td>
 133  
      *   <td>"Here is one line of\ntext that is going\nto be wrapped after\n20 columns."</td>
 134  
      *  </tr>
 135  
      *  <tr>
 136  
      *   <td>"Here is one line of text that is going to be wrapped after 20 columns."</td>
 137  
      *   <td>20</td>
 138  
      *   <td>"&lt;br /&gt;"</td>
 139  
      *   <td>true/false</td>
 140  
      *   <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>
 141  
      *  </tr>
 142  
      *  <tr>
 143  
      *   <td>"Here is one line of text that is going to be wrapped after 20 columns."</td>
 144  
      *   <td>20</td>
 145  
      *   <td>null</td>
 146  
      *   <td>true/false</td>
 147  
      *   <td>"Here is one line of" + systemNewLine + "text that is going" + systemNewLine + "to be wrapped after" + systemNewLine + "20 columns."</td>
 148  
      *  </tr>
 149  
      *  <tr>
 150  
      *   <td>"Click here to jump to the commons website - http://commons.apache.org"</td>
 151  
      *   <td>20</td>
 152  
      *   <td>"\n"</td>
 153  
      *   <td>false</td>
 154  
      *   <td>"Click here to jump\nto the commons\nwebsite -\nhttp://commons.apache.org"</td>
 155  
      *  </tr>
 156  
      *  <tr>
 157  
      *   <td>"Click here to jump to the commons website - http://commons.apache.org"</td>
 158  
      *   <td>20</td>
 159  
      *   <td>"\n"</td>
 160  
      *   <td>true</td>
 161  
      *   <td>"Click here to jump\nto the commons\nwebsite -\nhttp://commons.apach\ne.org"</td>
 162  
      *  </tr>
 163  
      * </table>
 164  
      *
 165  
      * @param str  the String to be word wrapped, may be null
 166  
      * @param wrapLength  the column to wrap the words at, less than 1 is treated as 1
 167  
      * @param newLineStr  the string to insert for a new line, 
 168  
      *  <code>null</code> uses the system property line separator
 169  
      * @param wrapLongWords  true if long words (such as URLs) should be wrapped
 170  
      * @return a line with newlines inserted, <code>null</code> if null input
 171  
      */
 172  
     public static String wrap(final String str, int wrapLength, String newLineStr, final boolean wrapLongWords) {
 173  38
         if (str == null) {
 174  8
             return null;
 175  
         }
 176  30
         if (newLineStr == null) {
 177  11
             newLineStr = SystemUtils.LINE_SEPARATOR;
 178  
         }
 179  30
         if (wrapLength < 1) {
 180  4
             wrapLength = 1;
 181  
         }
 182  30
         final int inputLineLength = str.length();
 183  30
         int offset = 0;
 184  30
         final StringBuilder wrappedLine = new StringBuilder(inputLineLength + 32);
 185  
         
 186  106
         while (inputLineLength - offset > wrapLength) {
 187  76
             if (str.charAt(offset) == ' ') {
 188  4
                 offset++;
 189  4
                 continue;
 190  
             }
 191  72
             int spaceToWrapAt = str.lastIndexOf(' ', wrapLength + offset);
 192  
 
 193  72
             if (spaceToWrapAt >= offset) {
 194  
                 // normal case
 195  59
                 wrappedLine.append(str.substring(offset, spaceToWrapAt));
 196  59
                 wrappedLine.append(newLineStr);
 197  59
                 offset = spaceToWrapAt + 1;
 198  
                 
 199  
             } else {
 200  
                 // really long word or URL
 201  13
                 if (wrapLongWords) {
 202  
                     // wrap really long word one line at a time
 203  2
                     wrappedLine.append(str.substring(offset, wrapLength + offset));
 204  2
                     wrappedLine.append(newLineStr);
 205  2
                     offset += wrapLength;
 206  
                 } else {
 207  
                     // do not wrap really long word, just extend beyond limit
 208  11
                     spaceToWrapAt = str.indexOf(' ', wrapLength + offset);
 209  11
                     if (spaceToWrapAt >= 0) {
 210  7
                         wrappedLine.append(str.substring(offset, spaceToWrapAt));
 211  7
                         wrappedLine.append(newLineStr);
 212  7
                         offset = spaceToWrapAt + 1;
 213  
                     } else {
 214  4
                         wrappedLine.append(str.substring(offset));
 215  4
                         offset = inputLineLength;
 216  
                     }
 217  
                 }
 218  
             }
 219  72
         }
 220  
 
 221  
         // Whatever is left in line is short enough to just pass through
 222  30
         wrappedLine.append(str.substring(offset));
 223  
 
 224  30
         return wrappedLine.toString();
 225  
     }
 226  
 
 227  
     // Capitalizing
 228  
     //-----------------------------------------------------------------------
 229  
     /**
 230  
      * <p>Capitalizes all the whitespace separated words in a String.
 231  
      * Only the first letter of each word is changed. To convert the 
 232  
      * rest of each word to lowercase at the same time, 
 233  
      * use {@link #capitalizeFully(String)}.</p>
 234  
      *
 235  
      * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.
 236  
      * A <code>null</code> input String returns <code>null</code>.
 237  
      * Capitalization uses the Unicode title case, normally equivalent to
 238  
      * upper case.</p>
 239  
      *
 240  
      * <pre>
 241  
      * WordUtils.capitalize(null)        = null
 242  
      * WordUtils.capitalize("")          = ""
 243  
      * WordUtils.capitalize("i am FINE") = "I Am FINE"
 244  
      * </pre>
 245  
      * 
 246  
      * @param str  the String to capitalize, may be null
 247  
      * @return capitalized String, <code>null</code> if null String input
 248  
      * @see #uncapitalize(String)
 249  
      * @see #capitalizeFully(String)
 250  
      */
 251  
     public static String capitalize(final String str) {
 252  9
         return capitalize(str, null);
 253  
     }
 254  
 
 255  
     /**
 256  
      * <p>Capitalizes all the delimiter separated words in a String.
 257  
      * Only the first letter of each word is changed. To convert the 
 258  
      * rest of each word to lowercase at the same time, 
 259  
      * use {@link #capitalizeFully(String, char[])}.</p>
 260  
      *
 261  
      * <p>The delimiters represent a set of characters understood to separate words.
 262  
      * The first string character and the first non-delimiter character after a
 263  
      * delimiter will be capitalized. </p>
 264  
      *
 265  
      * <p>A <code>null</code> input String returns <code>null</code>.
 266  
      * Capitalization uses the Unicode title case, normally equivalent to
 267  
      * upper case.</p>
 268  
      *
 269  
      * <pre>
 270  
      * WordUtils.capitalize(null, *)            = null
 271  
      * WordUtils.capitalize("", *)              = ""
 272  
      * WordUtils.capitalize(*, new char[0])     = *
 273  
      * WordUtils.capitalize("i am fine", null)  = "I Am Fine"
 274  
      * WordUtils.capitalize("i aM.fine", {'.'}) = "I aM.Fine"
 275  
      * </pre>
 276  
      * 
 277  
      * @param str  the String to capitalize, may be null
 278  
      * @param delimiters  set of characters to determine capitalization, null means whitespace
 279  
      * @return capitalized String, <code>null</code> if null String input
 280  
      * @see #uncapitalize(String)
 281  
      * @see #capitalizeFully(String)
 282  
      * @since 2.1
 283  
      */
 284  
     public static String capitalize(final String str, final char... delimiters) {
 285  35
         final int delimLen = delimiters == null ? -1 : delimiters.length;
 286  35
         if (StringUtils.isEmpty(str) || delimLen == 0) {
 287  5
             return str;
 288  
         }
 289  30
         final char[] buffer = str.toCharArray();
 290  30
         boolean capitalizeNext = true;
 291  286
         for (int i = 0; i < buffer.length; i++) {
 292  256
             final char ch = buffer[i];
 293  256
             if (isDelimiter(ch, delimiters)) {
 294  56
                 capitalizeNext = true;
 295  200
             } else if (capitalizeNext) {
 296  80
                 buffer[i] = Character.toTitleCase(ch);
 297  80
                 capitalizeNext = false;
 298  
             }
 299  
         }
 300  30
         return new String(buffer);
 301  
     }
 302  
 
 303  
     //-----------------------------------------------------------------------
 304  
     /**
 305  
      * <p>Converts all the whitespace separated words in a String into capitalized words, 
 306  
      * that is each word is made up of a titlecase character and then a series of 
 307  
      * lowercase characters.  </p>
 308  
      *
 309  
      * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.
 310  
      * A <code>null</code> input String returns <code>null</code>.
 311  
      * Capitalization uses the Unicode title case, normally equivalent to
 312  
      * upper case.</p>
 313  
      *
 314  
      * <pre>
 315  
      * WordUtils.capitalizeFully(null)        = null
 316  
      * WordUtils.capitalizeFully("")          = ""
 317  
      * WordUtils.capitalizeFully("i am FINE") = "I Am Fine"
 318  
      * </pre>
 319  
      * 
 320  
      * @param str  the String to capitalize, may be null
 321  
      * @return capitalized String, <code>null</code> if null String input
 322  
      */
 323  
     public static String capitalizeFully(final String str) {
 324  9
         return capitalizeFully(str, null);
 325  
     }
 326  
 
 327  
     /**
 328  
      * <p>Converts all the delimiter separated words in a String into capitalized words, 
 329  
      * that is each word is made up of a titlecase character and then a series of 
 330  
      * lowercase characters. </p>
 331  
      *
 332  
      * <p>The delimiters represent a set of characters understood to separate words.
 333  
      * The first string character and the first non-delimiter character after a
 334  
      * delimiter will be capitalized. </p>
 335  
      *
 336  
      * <p>A <code>null</code> input String returns <code>null</code>.
 337  
      * Capitalization uses the Unicode title case, normally equivalent to
 338  
      * upper case.</p>
 339  
      *
 340  
      * <pre>
 341  
      * WordUtils.capitalizeFully(null, *)            = null
 342  
      * WordUtils.capitalizeFully("", *)              = ""
 343  
      * WordUtils.capitalizeFully(*, null)            = *
 344  
      * WordUtils.capitalizeFully(*, new char[0])     = *
 345  
      * WordUtils.capitalizeFully("i aM.fine", {'.'}) = "I am.Fine"
 346  
      * </pre>
 347  
      * 
 348  
      * @param str  the String to capitalize, may be null
 349  
      * @param delimiters  set of characters to determine capitalization, null means whitespace
 350  
      * @return capitalized String, <code>null</code> if null String input
 351  
      * @since 2.1
 352  
      */
 353  
     public static String capitalizeFully(String str, final char... delimiters) {
 354  20
         final int delimLen = delimiters == null ? -1 : delimiters.length;
 355  20
         if (StringUtils.isEmpty(str) || delimLen == 0) {
 356  5
             return str;
 357  
         }
 358  15
         str = str.toLowerCase();
 359  15
         return capitalize(str, delimiters);
 360  
     }
 361  
 
 362  
     //-----------------------------------------------------------------------
 363  
     /**
 364  
      * <p>Uncapitalizes all the whitespace separated words in a String.
 365  
      * Only the first letter of each word is changed.</p>
 366  
      *
 367  
      * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.
 368  
      * A <code>null</code> input String returns <code>null</code>.</p>
 369  
      *
 370  
      * <pre>
 371  
      * WordUtils.uncapitalize(null)        = null
 372  
      * WordUtils.uncapitalize("")          = ""
 373  
      * WordUtils.uncapitalize("I Am FINE") = "i am fINE"
 374  
      * </pre>
 375  
      * 
 376  
      * @param str  the String to uncapitalize, may be null
 377  
      * @return uncapitalized String, <code>null</code> if null String input
 378  
      * @see #capitalize(String)
 379  
      */
 380  
     public static String uncapitalize(final String str) {
 381  9
         return uncapitalize(str, null);
 382  
     }
 383  
 
 384  
     /**
 385  
      * <p>Uncapitalizes all the whitespace separated words in a String.
 386  
      * Only the first letter of each word is changed.</p>
 387  
      *
 388  
      * <p>The delimiters represent a set of characters understood to separate words.
 389  
      * The first string character and the first non-delimiter character after a
 390  
      * delimiter will be uncapitalized. </p>
 391  
      *
 392  
      * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.
 393  
      * A <code>null</code> input String returns <code>null</code>.</p>
 394  
      *
 395  
      * <pre>
 396  
      * WordUtils.uncapitalize(null, *)            = null
 397  
      * WordUtils.uncapitalize("", *)              = ""
 398  
      * WordUtils.uncapitalize(*, null)            = *
 399  
      * WordUtils.uncapitalize(*, new char[0])     = *
 400  
      * WordUtils.uncapitalize("I AM.FINE", {'.'}) = "i AM.fINE"
 401  
      * </pre>
 402  
      * 
 403  
      * @param str  the String to uncapitalize, may be null
 404  
      * @param delimiters  set of characters to determine uncapitalization, null means whitespace
 405  
      * @return uncapitalized String, <code>null</code> if null String input
 406  
      * @see #capitalize(String)
 407  
      * @since 2.1
 408  
      */
 409  
     public static String uncapitalize(final String str, final char... delimiters) {
 410  20
         final int delimLen = delimiters == null ? -1 : delimiters.length;
 411  20
         if (StringUtils.isEmpty(str) || delimLen == 0) {
 412  5
             return str;
 413  
         }
 414  15
         final char[] buffer = str.toCharArray();
 415  15
         boolean uncapitalizeNext = true;
 416  143
         for (int i = 0; i < buffer.length; i++) {
 417  128
             final char ch = buffer[i];
 418  128
             if (isDelimiter(ch, delimiters)) {
 419  28
                 uncapitalizeNext = true;
 420  100
             } else if (uncapitalizeNext) {
 421  40
                 buffer[i] = Character.toLowerCase(ch);
 422  40
                 uncapitalizeNext = false;
 423  
             }
 424  
         }
 425  15
         return new String(buffer);
 426  
     }
 427  
 
 428  
     //-----------------------------------------------------------------------
 429  
     /**
 430  
      * <p>Swaps the case of a String using a word based algorithm.</p>
 431  
      * 
 432  
      * <ul>
 433  
      *  <li>Upper case character converts to Lower case</li>
 434  
      *  <li>Title case character converts to Lower case</li>
 435  
      *  <li>Lower case character after Whitespace or at start converts to Title case</li>
 436  
      *  <li>Other Lower case character converts to Upper case</li>
 437  
      * </ul>
 438  
      * 
 439  
      * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.
 440  
      * A <code>null</code> input String returns <code>null</code>.</p>
 441  
      * 
 442  
      * <pre>
 443  
      * StringUtils.swapCase(null)                 = null
 444  
      * StringUtils.swapCase("")                   = ""
 445  
      * StringUtils.swapCase("The dog has a BONE") = "tHE DOG HAS A bone"
 446  
      * </pre>
 447  
      * 
 448  
      * @param str  the String to swap case, may be null
 449  
      * @return the changed String, <code>null</code> if null String input
 450  
      */
 451  
     public static String swapCase(final String str) {
 452  13
         if (StringUtils.isEmpty(str)) {
 453  2
             return str;
 454  
         }
 455  11
         final char[] buffer = str.toCharArray();
 456  
 
 457  11
         boolean whitespace = true;
 458  
 
 459  159
         for (int i = 0; i < buffer.length; i++) {
 460  148
             final char ch = buffer[i];
 461  148
             if (Character.isUpperCase(ch)) {
 462  24
                 buffer[i] = Character.toLowerCase(ch);
 463  24
                 whitespace = false;
 464  124
             } else if (Character.isTitleCase(ch)) {
 465  2
                 buffer[i] = Character.toLowerCase(ch);
 466  2
                 whitespace = false;
 467  122
             } else if (Character.isLowerCase(ch)) {
 468  82
                 if (whitespace) {
 469  13
                     buffer[i] = Character.toTitleCase(ch);
 470  13
                     whitespace = false;
 471  
                 } else {
 472  69
                     buffer[i] = Character.toUpperCase(ch);
 473  
                 }
 474  
             } else {
 475  40
                 whitespace = Character.isWhitespace(ch);
 476  
             }
 477  
         }
 478  11
         return new String(buffer);
 479  
     }
 480  
 
 481  
     //-----------------------------------------------------------------------
 482  
     /**
 483  
      * <p>Extracts the initial letters from each word in the String.</p>
 484  
      * 
 485  
      * <p>The first letter of the string and all first letters after
 486  
      * whitespace are returned as a new string.
 487  
      * Their case is not changed.</p>
 488  
      *
 489  
      * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.
 490  
      * A <code>null</code> input String returns <code>null</code>.</p>
 491  
      *
 492  
      * <pre>
 493  
      * WordUtils.initials(null)             = null
 494  
      * WordUtils.initials("")               = ""
 495  
      * WordUtils.initials("Ben John Lee")   = "BJL"
 496  
      * WordUtils.initials("Ben J.Lee")      = "BJ"
 497  
      * </pre>
 498  
      *
 499  
      * @param str  the String to get initials from, may be null
 500  
      * @return String of initial letters, <code>null</code> if null String input
 501  
      * @see #initials(String,char[])
 502  
      * @since 2.2
 503  
      */
 504  
     public static String initials(final String str) {
 505  9
         return initials(str, null);
 506  
     }
 507  
 
 508  
     /**
 509  
      * <p>Extracts the initial letters from each word in the String.</p>
 510  
      * 
 511  
      * <p>The first letter of the string and all first letters after the
 512  
      * defined delimiters are returned as a new string.
 513  
      * Their case is not changed.</p>
 514  
      *
 515  
      * <p>If the delimiters array is null, then Whitespace is used.
 516  
      * Whitespace is defined by {@link Character#isWhitespace(char)}.
 517  
      * A <code>null</code> input String returns <code>null</code>.
 518  
      * An empty delimiter array returns an empty String.</p>
 519  
      *
 520  
      * <pre>
 521  
      * WordUtils.initials(null, *)                = null
 522  
      * WordUtils.initials("", *)                  = ""
 523  
      * WordUtils.initials("Ben John Lee", null)   = "BJL"
 524  
      * WordUtils.initials("Ben J.Lee", null)      = "BJ"
 525  
      * WordUtils.initials("Ben J.Lee", [' ','.']) = "BJL"
 526  
      * WordUtils.initials(*, new char[0])         = ""
 527  
      * </pre>
 528  
      * 
 529  
      * @param str  the String to get initials from, may be null
 530  
      * @param delimiters  set of characters to determine words, null means whitespace
 531  
      * @return String of initial letters, <code>null</code> if null String input
 532  
      * @see #initials(String)
 533  
      * @since 2.2
 534  
      */
 535  
     public static String initials(final String str, final char... delimiters) {
 536  75
         if (StringUtils.isEmpty(str)) {
 537  14
             return str;
 538  
         }
 539  61
         if (delimiters != null && delimiters.length == 0) {
 540  9
             return "";
 541  
         }
 542  52
         final int strLen = str.length();
 543  52
         final char[] buf = new char[strLen / 2 + 1];
 544  52
         int count = 0;
 545  52
         boolean lastWasGap = true;
 546  463
         for (int i = 0; i < strLen; i++) {
 547  411
             final char ch = str.charAt(i);
 548  
 
 549  411
             if (isDelimiter(ch, delimiters)) {
 550  93
                 lastWasGap = true;
 551  318
             } else if (lastWasGap) {
 552  100
                 buf[count++] = ch;
 553  100
                 lastWasGap = false;
 554  
             } else {
 555  
                 continue; // ignore ch
 556  
             }
 557  
         }
 558  52
         return new String(buf, 0, count);
 559  
     }
 560  
 
 561  
     //-----------------------------------------------------------------------
 562  
     /**
 563  
      * Is the character a delimiter.
 564  
      *
 565  
      * @param ch  the character to check
 566  
      * @param delimiters  the delimiters
 567  
      * @return true if it is a delimiter
 568  
      */
 569  
     private static boolean isDelimiter(final char ch, final char[] delimiters) {
 570  795
         if (delimiters == null) {
 571  322
             return Character.isWhitespace(ch);
 572  
         }
 573  1689
         for (final char delimiter : delimiters) {
 574  1317
             if (ch == delimiter) {
 575  101
                 return true;
 576  
             }
 577  
         }
 578  372
         return false;
 579  
     }
 580  
 
 581  
 }