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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.collections.map;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.Collection;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.SortedMap;
import org.apache.commons.collections.BoundedMap;
import org.apache.commons.collections.collection.UnmodifiableCollection;
import org.apache.commons.collections.set.UnmodifiableSet;
/**
* Decorates another SortedMap to fix the size blocking add/remove.
*
* Any action that would change the size of the map is disallowed.
* The put method is allowed to change the value associated with an existing
* key however.
*
* If trying to remove or clear the map, an UnsupportedOperationException is
* thrown. If trying to put a new mapping into the map, an
* IllegalArgumentException is thrown. This is because the put method can
* succeed if the mapping's key already exists in the map, so the put method
* is not always unsupported.
*
* Note that FixedSizeSortedMap is not synchronized and is not thread-safe.
* If you wish to use this map from multiple threads concurrently, you must use
* appropriate synchronization. The simplest approach is to wrap this map
* using {@link java.util.Collections#synchronizedSortedMap}. This class may throw
* exceptions when accessed by concurrent threads without synchronization.
*
* This class is Serializable from Commons Collections 3.1.
*
* @since Commons Collections 3.0
* @version $Revision: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $
*
* @author Stephen Colebourne
* @author Paul Jack
*/
public class FixedSizeSortedMap
extends AbstractSortedMapDecorator
implements SortedMap, BoundedMap, Serializable {
/** Serialization version */
private static final long serialVersionUID = 3126019624511683653L;
/**
* Factory method to create a fixed size sorted map.
*
* @param map the map to decorate, must not be null
* @throws IllegalArgumentException if map is null
*/
public static SortedMap decorate(SortedMap map) {
return new FixedSizeSortedMap(map);
}
//-----------------------------------------------------------------------
/**
* Constructor that wraps (not copies).
*
* @param map the map to decorate, must not be null
* @throws IllegalArgumentException if map is null
*/
protected FixedSizeSortedMap(SortedMap map) {
super(map);
}
/**
* Gets the map being decorated.
*
* @return the decorated map
*/
protected SortedMap getSortedMap() {
return (SortedMap) map;
}
//-----------------------------------------------------------------------
/**
* Write the map out using a custom routine.
*/
private void writeObject(ObjectOutputStream out) throws IOException {
out.defaultWriteObject();
out.writeObject(map);
}
/**
* Read the map in using a custom routine.
*/
private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
in.defaultReadObject();
map = (Map) in.readObject();
}
//-----------------------------------------------------------------------
public Object put(Object key, Object value) {
if (map.containsKey(key) == false) {
throw new IllegalArgumentException("Cannot put new key/value pair - Map is fixed size");
}
return map.put(key, value);
}
public void putAll(Map mapToCopy) {
for (Iterator it = mapToCopy.keySet().iterator(); it.hasNext(); ) {
if (mapToCopy.containsKey(it.next()) == false) {
throw new IllegalArgumentException("Cannot put new key/value pair - Map is fixed size");
}
}
map.putAll(mapToCopy);
}
public void clear() {
throw new UnsupportedOperationException("Map is fixed size");
}
public Object remove(Object key) {
throw new UnsupportedOperationException("Map is fixed size");
}
public Set entrySet() {
Set set = map.entrySet();
return UnmodifiableSet.decorate(set);
}
public Set keySet() {
Set set = map.keySet();
return UnmodifiableSet.decorate(set);
}
public Collection values() {
Collection coll = map.values();
return UnmodifiableCollection.decorate(coll);
}
//-----------------------------------------------------------------------
public SortedMap subMap(Object fromKey, Object toKey) {
SortedMap map = getSortedMap().subMap(fromKey, toKey);
return new FixedSizeSortedMap(map);
}
public SortedMap headMap(Object toKey) {
SortedMap map = getSortedMap().headMap(toKey);
return new FixedSizeSortedMap(map);
}
public SortedMap tailMap(Object fromKey) {
SortedMap map = getSortedMap().tailMap(fromKey);
return new FixedSizeSortedMap(map);
}
public boolean isFull() {
return true;
}
public int maxSize() {
return size();
}
}