001: /*
002: * $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 $
003: * ====================================================================
004: * The Apache Software License, Version 1.1
005: *
006: * Copyright (c) 2003 The Apache Software Foundation. All rights
007: * reserved.
008: *
009: * Redistribution and use in source and binary forms, with or without
010: * modification, are permitted provided that the following conditions
011: * are met:
012: *
013: * 1. Redistributions of source code must retain the above copyright
014: * notice, this list of conditions and the following disclaimer.
015: *
016: * 2. Redistributions in binary form must reproduce the above copyright
017: * notice, this list of conditions and the following disclaimer in
018: * the documentation and/or other materials provided with the
019: * distribution.
020: *
021: * 3. The end-user documentation included with the redistribution, if
022: * any, must include the following acknowledgement:
023: * "This product includes software developed by the
024: * Apache Software Foundation (http://www.apache.org/)."
025: * Alternately, this acknowledgement may appear in the software itself,
026: * if and wherever such third-party acknowledgements normally appear.
027: *
028: * 4. The names "The Jakarta Project", "Commons", and "Apache Software
029: * Foundation" must not be used to endorse or promote products derived
030: * from this software without prior written permission. For written
031: * permission, please contact apache@apache.org.
032: *
033: * 5. Products derived from this software may not be called "Apache"
034: * nor may "Apache" appear in their names without prior written
035: * permission of the Apache Software Foundation.
036: *
037: * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
038: * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
039: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
040: * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
041: * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
042: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
043: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
044: * USE, DATA, OR PROFITS; OR BUSINESS CharERRUPTION) HOWEVER CAUSED AND
045: * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
046: * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
047: * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
048: * SUCH DAMAGE.
049: * ====================================================================
050: *
051: * This software consists of voluntary contributions made by many
052: * individuals on behalf of the Apache Software Foundation. For more
053: * information on the Apache Software Foundation, please see
054: * <http://www.apache.org/>.
055: *
056: */
057:
058: package org.apache.commons.collections.primitives;
059:
060: import org.apache.commons.collections.primitives.decorators.UnmodifiableCharIterator;
061: import org.apache.commons.collections.primitives.decorators.UnmodifiableCharList;
062: import org.apache.commons.collections.primitives.decorators.UnmodifiableCharListIterator;
063:
064: /**
065: * This class consists exclusively of static methods that operate on or
066: * return CharCollections.
067: * <p>
068: * The methods of this class all throw a NullPoCharerException if the
069: * provided collection is null.
070: *
071: * @version $Revision: 1.1 $ $Date: 2003/10/29 19:20:08 $
072: *
073: * @author Rodney Waldhoff
074: */
075: public final class CharCollections {
076:
077: /**
078: * Returns an unmodifiable CharList containing only the specified element.
079: * @param value the single value
080: * @return an unmodifiable CharList containing only the specified element.
081: */
082: public static CharList singletonCharList(char value) {
083: // TODO: a specialized implementation of CharList may be more performant
084: CharList list = new ArrayCharList(1);
085: list.add(value);
086: return UnmodifiableCharList.wrap(list);
087: }
088:
089: /**
090: * Returns an unmodifiable CharIterator containing only the specified element.
091: * @param value the single value
092: * @return an unmodifiable CharIterator containing only the specified element.
093: */
094: public static CharIterator singletonCharIterator(char value) {
095: return singletonCharList(value).iterator();
096: }
097:
098: /**
099: * 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)
115: throws NullPointerException {
116: if (null == list) {
117: throw new NullPointerException();
118: }
119: return UnmodifiableCharList.wrap(list);
120: }
121:
122: /**
123: * Returns an unmodifiable version of the given non-null CharIterator.
124: * @param iter the non-null CharIterator to wrap in an unmodifiable decorator
125: * @return an unmodifiable version of the given non-null CharIterator
126: * @throws NullPoCharerException if the given CharIterator is null
127: * @see org.apache.commons.collections.primitives.decorators.UnmodifiableCharIterator#wrap
128: */
129: public static CharIterator unmodifiableCharIterator(
130: CharIterator iter) {
131: if (null == iter) {
132: throw new NullPointerException();
133: }
134: return UnmodifiableCharIterator.wrap(iter);
135: }
136:
137: /**
138: * Returns an unmodifiable version of the given non-null CharListIterator.
139: * @param iter the non-null CharListIterator to wrap in an unmodifiable decorator
140: * @return an unmodifiable version of the given non-null CharListIterator
141: * @throws NullPoCharerException if the given CharListIterator is null
142: * @see org.apache.commons.collections.primitives.decorators.UnmodifiableCharListIterator#wrap
143: */
144: public static CharListIterator unmodifiableCharListIterator(
145: CharListIterator iter) {
146: if (null == iter) {
147: throw new NullPointerException();
148: }
149: return UnmodifiableCharListIterator.wrap(iter);
150: }
151:
152: /**
153: * Returns an unmodifiable, empty CharList.
154: * @return an unmodifiable, empty CharList.
155: * @see #EMPTY_CHAR_LIST
156: */
157: public static CharList getEmptyCharList() {
158: return EMPTY_CHAR_LIST;
159: }
160:
161: /**
162: * Returns an unmodifiable, empty CharIterator
163: * @return an unmodifiable, empty CharIterator.
164: * @see #EMPTY_CHAR_ITERATOR
165: */
166: public static CharIterator getEmptyCharIterator() {
167: return EMPTY_CHAR_ITERATOR;
168: }
169:
170: /**
171: * Returns an unmodifiable, empty CharListIterator
172: * @return an unmodifiable, empty CharListIterator.
173: * @see #EMPTY_CHAR_LIST_ITERATOR
174: */
175: public static CharListIterator getEmptyCharListIterator() {
176: return EMPTY_CHAR_LIST_ITERATOR;
177: }
178:
179: /**
180: * An unmodifiable, empty CharList
181: * @see #getEmptyCharList
182: */
183: public static final CharList EMPTY_CHAR_LIST = unmodifiableCharList(new ArrayCharList(
184: 0));
185:
186: /**
187: * An unmodifiable, empty CharIterator
188: * @see #getEmptyCharIterator
189: */
190: public static final CharIterator EMPTY_CHAR_ITERATOR = unmodifiableCharIterator(EMPTY_CHAR_LIST
191: .iterator());
192:
193: /**
194: * An unmodifiable, empty CharListIterator
195: * @see #getEmptyCharListIterator
196: */
197: public static final CharListIterator EMPTY_CHAR_LIST_ITERATOR = unmodifiableCharListIterator(EMPTY_CHAR_LIST
198: .listIterator());
199: }
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