1. /*

  2.  * $Header: /home/cvs/jakarta-commons/primitives/src/java/org/apache/commons/collections/primitives/CharCollections.java,v 1.1 2003/10/29 19:20:08 rwaldhoff Exp $

  3.  * ====================================================================

  4.  * The Apache Software License, Version 1.1

  5.  *

  6.  * Copyright (c) 2003 The Apache Software Foundation.  All rights

  7.  * reserved.

  8.  *

  9.  * Redistribution and use in source and binary forms, with or without

  10.  * modification, are permitted provided that the following conditions

  11.  * are met:

  12.  *

  13.  * 1. Redistributions of source code must retain the above copyright

  14.  *    notice, this list of conditions and the following disclaimer.

  15.  *

  16.  * 2. Redistributions in binary form must reproduce the above copyright

  17.  *    notice, this list of conditions and the following disclaimer in

  18.  *    the documentation and/or other materials provided with the

  19.  *    distribution.

  20.  *

  21.  * 3. The end-user documentation included with the redistribution, if

  22.  *    any, must include the following acknowledgement:

  23.  *       "This product includes software developed by the

  24.  *        Apache Software Foundation (http://www.apache.org/)."

  25.  *    Alternately, this acknowledgement may appear in the software itself,

  26.  *    if and wherever such third-party acknowledgements normally appear.

  27.  *

  28.  * 4. The names "The Jakarta Project", "Commons", and "Apache Software

  29.  *    Foundation" must not be used to endorse or promote products derived

  30.  *    from this software without prior written permission. For written

  31.  *    permission, please contact apache@apache.org.

  32.  *

  33.  * 5. Products derived from this software may not be called "Apache"

  34.  *    nor may "Apache" appear in their names without prior written

  35.  *    permission of the Apache Software Foundation.

  36.  *

  37.  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED

  38.  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

  39.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

  40.  * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR

  41.  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

  42.  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

  43.  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF

  44.  * USE, DATA, OR PROFITS; OR BUSINESS CharERRUPTION) HOWEVER CAUSED AND

  45.  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,

  46.  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT

  47.  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

  48.  * SUCH DAMAGE.

  49.  * ====================================================================

  50.  *

  51.  * This software consists of voluntary contributions made by many

  52.  * individuals on behalf of the Apache Software Foundation.  For more

  53.  * information on the Apache Software Foundation, please see

  54.  * <http://www.apache.org/>.

  55.  *

  56.  */

  57. 

  58. package org.apache.commons.collections.primitives;

  59. 

  60. import org.apache.commons.collections.primitives.decorators.UnmodifiableCharIterator;

  61. import org.apache.commons.collections.primitives.decorators.UnmodifiableCharList;

  62. import org.apache.commons.collections.primitives.decorators.UnmodifiableCharListIterator;

  63. 

  64. /**

  65.  * This class consists exclusively of static methods that operate on or

  66.  * return CharCollections.

  67.  * <p>

  68.  * The methods of this class all throw a NullPoCharerException if the 

  69.  * provided collection is null.

  70.  * 

  71.  * @version $Revision: 1.1 $ $Date: 2003/10/29 19:20:08 $

  72.  * 

  73.  * @author Rodney Waldhoff 

  74.  */

  75. public final class CharCollections {

  76. 

  77.     /**

  78.      * Returns an unmodifiable CharList containing only the specified element.

  79.      * @param value the single value

  80.      * @return an unmodifiable CharList containing only the specified element.

  81.      */    

  82.     public static CharList singletonCharList(char value) {

  83.         // TODO: a specialized implementation of CharList may be more performant

  84.         CharList list = new ArrayCharList(1);

  85.         list.add(value);

  86.         return UnmodifiableCharList.wrap(list);

  87.     }

  88. 

  89.     /**

  90.      * Returns an unmodifiable CharIterator containing only the specified element.

  91.      * @param value the single value

  92.      * @return an unmodifiable CharIterator containing only the specified element.

  93.      */    

  94.     public static CharIterator singletonCharIterator(char value) {

  95.         return singletonCharList(value).iterator();

  96.     }

  97. 

  98.     /**

  99.      * Returns an unmodifiable CharListIterator containing only the specified element.

  100.      * @param value the single value

  101.      * @return an unmodifiable CharListIterator containing only the specified element.

  102.      */    

  103.     public static CharListIterator singletonCharListIterator(char value) {

  104.         return singletonCharList(value).listIterator();

  105.     }

  106. 

  107.     /**

  108.      * Returns an unmodifiable version of the given non-null CharList.

  109.      * @param list the non-null CharList to wrap in an unmodifiable decorator

  110.      * @return an unmodifiable version of the given non-null CharList

  111.      * @throws NullPoCharerException if the given CharList is null

  112.      * @see org.apache.commons.collections.primitives.decorators.UnmodifiableCharList#wrap

  113.      */    

  114.     public static CharList unmodifiableCharList(CharList list) throws NullPointerException {

  115.         if(null == list) {

  116.             throw new NullPointerException();

  117.         }

  118.         return UnmodifiableCharList.wrap(list);

  119.     }

  120.     

  121.     /**

  122.      * Returns an unmodifiable version of the given non-null CharIterator.

  123.      * @param iter the non-null CharIterator to wrap in an unmodifiable decorator

  124.      * @return an unmodifiable version of the given non-null CharIterator

  125.      * @throws NullPoCharerException if the given CharIterator is null

  126.      * @see org.apache.commons.collections.primitives.decorators.UnmodifiableCharIterator#wrap

  127.      */    

  128.     public static CharIterator unmodifiableCharIterator(CharIterator iter) {

  129.         if(null == iter) {

  130.             throw new NullPointerException();

  131.         }

  132.         return UnmodifiableCharIterator.wrap(iter);

  133.     }

  134.         

  135.     /**

  136.      * Returns an unmodifiable version of the given non-null CharListIterator.

  137.      * @param iter the non-null CharListIterator to wrap in an unmodifiable decorator

  138.      * @return an unmodifiable version of the given non-null CharListIterator

  139.      * @throws NullPoCharerException if the given CharListIterator is null

  140.      * @see org.apache.commons.collections.primitives.decorators.UnmodifiableCharListIterator#wrap

  141.      */    

  142.     public static CharListIterator unmodifiableCharListIterator(CharListIterator iter) {

  143.         if(null == iter) {

  144.             throw new NullPointerException();

  145.         }

  146.         return UnmodifiableCharListIterator.wrap(iter);

  147.     }

  148.     

  149.     /**

  150.      * Returns an unmodifiable, empty CharList.

  151.      * @return an unmodifiable, empty CharList.

  152.      * @see #EMPTY_CHAR_LIST

  153.      */    

  154.     public static CharList getEmptyCharList() {

  155.         return EMPTY_CHAR_LIST;

  156.     }

  157.     

  158.     /**

  159.      * Returns an unmodifiable, empty CharIterator

  160.      * @return an unmodifiable, empty CharIterator.

  161.      * @see #EMPTY_CHAR_ITERATOR

  162.      */    

  163.     public static CharIterator getEmptyCharIterator() {

  164.         return EMPTY_CHAR_ITERATOR;

  165.     }

  166.     

  167.     /**

  168.      * Returns an unmodifiable, empty CharListIterator

  169.      * @return an unmodifiable, empty CharListIterator.

  170.      * @see #EMPTY_CHAR_LIST_ITERATOR

  171.      */    

  172.     public static CharListIterator getEmptyCharListIterator() {

  173.         return EMPTY_CHAR_LIST_ITERATOR;

  174.     }    

  175. 

  176.     /**

  177.      * An unmodifiable, empty CharList

  178.      * @see #getEmptyCharList

  179.      */    

  180.     public static final CharList EMPTY_CHAR_LIST = unmodifiableCharList(new ArrayCharList(0));

  181. 

  182.     /**

  183.      * An unmodifiable, empty CharIterator

  184.      * @see #getEmptyCharIterator

  185.      */    

  186.     public static final CharIterator EMPTY_CHAR_ITERATOR = unmodifiableCharIterator(EMPTY_CHAR_LIST.iterator());

  187. 

  188.     /**

  189.      * An unmodifiable, empty CharListIterator

  190.      * @see #getEmptyCharListIterator

  191.      */    

  192.     public static final CharListIterator EMPTY_CHAR_LIST_ITERATOR = unmodifiableCharListIterator(EMPTY_CHAR_LIST.listIterator());

  193. }