org.apache.commons.collections.map.FixedSizeMap Maven / Gradle / Ivy
Show all versions of commons-collections Show documentation
/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2003-2004 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowledgement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgement may appear in the software itself,
* if and wherever such third-party acknowledgements normally appear.
*
* 4. The names "The Jakarta Project", "Commons", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact [email protected].
*
* 5. Products derived from this software may not be called "Apache"
* nor may "Apache" appear in their names without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* .
*/
package org.apache.commons.collections.map;
import java.util.Collection;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import org.apache.commons.collections.BoundedMap;
import org.apache.commons.collections.collection.UnmodifiableCollection;
import org.apache.commons.collections.set.UnmodifiableSet;
/**
* Decorates another Map
to fix the size, preventing 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.
*
* @since Commons Collections 3.0
* @version $Revision: 1.4 $ $Date: 2004/01/14 21:43:11 $
*
* @author Stephen Colebourne
* @author Paul Jack
*/
public class FixedSizeMap
extends AbstractMapDecorator implements Map, BoundedMap {
/**
* Factory method to create a fixed size map.
*
* @param map the map to decorate, must not be null
* @throws IllegalArgumentException if map is null
*/
public static Map decorate(Map map) {
return new FixedSizeMap(map);
}
//-----------------------------------------------------------------------
/**
* Constructor that wraps (not copies).
*
* @param map the map to decorate, must not be null
* @throws IllegalArgumentException if map is null
*/
protected FixedSizeMap(Map map) {
super(map);
}
//-----------------------------------------------------------------------
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 boolean isFull() {
return true;
}
public int maxSize() {
return size();
}
}