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.collections.primitives;
018
019 /**
020 * Abstract base class for {@link ByteCollection}s.
021 * <p />
022 * Read-only subclasses must override {@link #iterator}
023 * and {@link #size}. Mutable subclasses
024 * should also override {@link #add} and
025 * {@link ByteIterator#remove ByteIterator.remove}.
026 * All other methods have at least some base implementation
027 * derived from these. Subclasses may choose to override
028 * these methods to provide a more efficient implementation.
029 *
030 * @since Commons Primitives 1.0
031 * @version $Revision: 480460 $ $Date: 2006-11-29 09:14:21 +0100 (Wed, 29 Nov 2006) $
032 *
033 * @author Rodney Waldhoff
034 */
035 public abstract class AbstractByteCollection implements ByteCollection {
036 public abstract ByteIterator iterator();
037 public abstract int size();
038
039 protected AbstractByteCollection() { }
040
041 /** Unsupported in this base implementation. */
042 public boolean add(byte element) {
043 throw new UnsupportedOperationException("add(byte) is not supported.");
044 }
045
046 public boolean addAll(ByteCollection c) {
047 boolean modified = false;
048 for(ByteIterator iter = c.iterator(); iter.hasNext(); ) {
049 modified |= add(iter.next());
050 }
051 return modified;
052 }
053
054 public void clear() {
055 for(ByteIterator iter = iterator(); iter.hasNext();) {
056 iter.next();
057 iter.remove();
058 }
059 }
060
061 public boolean contains(byte element) {
062 for(ByteIterator iter = iterator(); iter.hasNext();) {
063 if(iter.next() == element) {
064 return true;
065 }
066 }
067 return false;
068 }
069
070 public boolean containsAll(ByteCollection c) {
071 for(ByteIterator iter = c.iterator(); iter.hasNext();) {
072 if(!contains(iter.next())) {
073 return false;
074 }
075 }
076 return true;
077 }
078
079 public boolean isEmpty() {
080 return (0 == size());
081 }
082
083 public boolean removeElement(byte element) {
084 for(ByteIterator iter = iterator(); iter.hasNext();) {
085 if(iter.next() == element) {
086 iter.remove();
087 return true;
088 }
089 }
090 return false;
091 }
092
093 public boolean removeAll(ByteCollection c) {
094 boolean modified = false;
095 for(ByteIterator iter = c.iterator(); iter.hasNext(); ) {
096 modified |= removeElement(iter.next());
097 }
098 return modified;
099 }
100
101 public boolean retainAll(ByteCollection c) {
102 boolean modified = false;
103 for(ByteIterator iter = iterator(); iter.hasNext();) {
104 if(!c.contains(iter.next())) {
105 iter.remove();
106 modified = true;
107 }
108 }
109 return modified;
110 }
111
112 public byte[] toArray() {
113 byte[] array = new byte[size()];
114 int i = 0;
115 for(ByteIterator iter = iterator(); iter.hasNext();) {
116 array[i] = iter.next();
117 i++;
118 }
119 return array;
120 }
121
122 public byte[] toArray(byte[] a) {
123 if(a.length < size()) {
124 return toArray();
125 } else {
126 int i = 0;
127 for(ByteIterator iter = iterator(); iter.hasNext();) {
128 a[i] = iter.next();
129 i++;
130 }
131 return a;
132 }
133 }
134 }