org.apache.commons.collections.map.UnmodifiableMap Maven / Gradle / Ivy
/*
* 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.Map;
import java.util.Set;
import org.apache.commons.collections.IterableMap;
import org.apache.commons.collections.MapIterator;
import org.apache.commons.collections.Unmodifiable;
import org.apache.commons.collections.collection.UnmodifiableCollection;
import org.apache.commons.collections.iterators.EntrySetMapIterator;
import org.apache.commons.collections.iterators.UnmodifiableMapIterator;
import org.apache.commons.collections.set.UnmodifiableSet;
/**
* Decorates another Map to ensure it can't be altered.
*
* 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
*/
public final class UnmodifiableMap
extends AbstractMapDecorator
implements IterableMap, Unmodifiable, Serializable {
/** Serialization version */
private static final long serialVersionUID = 2737023427269031941L;
/**
* Factory method to create an unmodifiable map.
*
* @param map the map to decorate, must not be null
* @throws IllegalArgumentException if map is null
*/
public static Map decorate(Map map) {
if (map instanceof Unmodifiable) {
return map;
}
return new UnmodifiableMap(map);
}
//-----------------------------------------------------------------------
/**
* Constructor that wraps (not copies).
*
* @param map the map to decorate, must not be null
* @throws IllegalArgumentException if map is null
*/
private UnmodifiableMap(Map map) {
super(map);
}
//-----------------------------------------------------------------------
/**
* Write the map out using a custom routine.
*
* @param out the output stream
* @throws IOException
* @since Commons Collections 3.1
*/
private void writeObject(ObjectOutputStream out) throws IOException {
out.defaultWriteObject();
out.writeObject(map);
}
/**
* Read the map in using a custom routine.
*
* @param in the input stream
* @throws IOException
* @throws ClassNotFoundException
* @since Commons Collections 3.1
*/
private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
in.defaultReadObject();
map = (Map) in.readObject();
}
//-----------------------------------------------------------------------
public void clear() {
throw new UnsupportedOperationException();
}
public Object put(Object key, Object value) {
throw new UnsupportedOperationException();
}
public void putAll(Map mapToCopy) {
throw new UnsupportedOperationException();
}
public Object remove(Object key) {
throw new UnsupportedOperationException();
}
public MapIterator mapIterator() {
if (map instanceof IterableMap) {
MapIterator it = ((IterableMap) map).mapIterator();
return UnmodifiableMapIterator.decorate(it);
} else {
MapIterator it = new EntrySetMapIterator(map);
return UnmodifiableMapIterator.decorate(it);
}
}
public Set entrySet() {
Set set = super.entrySet();
return UnmodifiableEntrySet.decorate(set);
}
public Set keySet() {
Set set = super.keySet();
return UnmodifiableSet.decorate(set);
}
public Collection values() {
Collection coll = super.values();
return UnmodifiableCollection.decorate(coll);
}
}