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.list; 018 019 import java.util.Collection; 020 import java.util.Iterator; 021 import java.util.List; 022 import java.util.ListIterator; 023 024 import org.apache.commons.collections.BoundedCollection; 025 import org.apache.commons.collections.iterators.AbstractListIteratorDecorator; 026 import org.apache.commons.collections.iterators.UnmodifiableIterator; 027 028 /** 029 * Decorates another <code>List</code> to fix the size preventing add/remove. 030 * <p> 031 * The add, remove, clear and retain operations are unsupported. 032 * The set method is allowed (as it doesn't change the list size). 033 * <p> 034 * This class is Serializable from Commons Collections 3.1. 035 * 036 * @since Commons Collections 3.0 037 * @version $Revision: 646777 $ $Date: 2008-04-10 13:33:15 +0100 (Thu, 10 Apr 2008) $ 038 * 039 * @author Stephen Colebourne 040 * @author Paul Jack 041 */ 042 public class FixedSizeList 043 extends AbstractSerializableListDecorator 044 implements BoundedCollection { 045 046 /** Serialization version */ 047 private static final long serialVersionUID = -2218010673611160319L; 048 049 /** 050 * Factory method to create a fixed size list. 051 * 052 * @param list the list to decorate, must not be null 053 * @throws IllegalArgumentException if list is null 054 */ 055 public static List decorate(List list) { 056 return new FixedSizeList(list); 057 } 058 059 //----------------------------------------------------------------------- 060 /** 061 * Constructor that wraps (not copies). 062 * 063 * @param list the list to decorate, must not be null 064 * @throws IllegalArgumentException if list is null 065 */ 066 protected FixedSizeList(List list) { 067 super(list); 068 } 069 070 //----------------------------------------------------------------------- 071 public boolean add(Object object) { 072 throw new UnsupportedOperationException("List is fixed size"); 073 } 074 075 public void add(int index, Object object) { 076 throw new UnsupportedOperationException("List is fixed size"); 077 } 078 079 public boolean addAll(Collection coll) { 080 throw new UnsupportedOperationException("List is fixed size"); 081 } 082 083 public boolean addAll(int index, Collection coll) { 084 throw new UnsupportedOperationException("List is fixed size"); 085 } 086 087 public void clear() { 088 throw new UnsupportedOperationException("List is fixed size"); 089 } 090 091 public Object get(int index) { 092 return getList().get(index); 093 } 094 095 public int indexOf(Object object) { 096 return getList().indexOf(object); 097 } 098 099 public Iterator iterator() { 100 return UnmodifiableIterator.decorate(getCollection().iterator()); 101 } 102 103 public int lastIndexOf(Object object) { 104 return getList().lastIndexOf(object); 105 } 106 107 public ListIterator listIterator() { 108 return new FixedSizeListIterator(getList().listIterator(0)); 109 } 110 111 public ListIterator listIterator(int index) { 112 return new FixedSizeListIterator(getList().listIterator(index)); 113 } 114 115 public Object remove(int index) { 116 throw new UnsupportedOperationException("List is fixed size"); 117 } 118 119 public boolean remove(Object object) { 120 throw new UnsupportedOperationException("List is fixed size"); 121 } 122 123 public boolean removeAll(Collection coll) { 124 throw new UnsupportedOperationException("List is fixed size"); 125 } 126 127 public boolean retainAll(Collection coll) { 128 throw new UnsupportedOperationException("List is fixed size"); 129 } 130 131 public Object set(int index, Object object) { 132 return getList().set(index, object); 133 } 134 135 public List subList(int fromIndex, int toIndex) { 136 List sub = getList().subList(fromIndex, toIndex); 137 return new FixedSizeList(sub); 138 } 139 140 /** 141 * List iterator that only permits changes via set() 142 */ 143 static class FixedSizeListIterator extends AbstractListIteratorDecorator { 144 protected FixedSizeListIterator(ListIterator iterator) { 145 super(iterator); 146 } 147 public void remove() { 148 throw new UnsupportedOperationException("List is fixed size"); 149 } 150 public void add(Object object) { 151 throw new UnsupportedOperationException("List is fixed size"); 152 } 153 } 154 155 public boolean isFull() { 156 return true; 157 } 158 159 public int maxSize() { 160 return size(); 161 } 162 163 }