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Commons Collections example source code file (UnmodifiableMap.java)

This example Commons Collections source code file (UnmodifiableMap.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Commons Collections tags/keywords

collection, io, ioexception, iterablemap, map, mapiterator, object, object, set, set, unmodifiable, unmodifiablemap, unmodifiablemap, unsupportedoperationexception, unsupportedoperationexception, util

The Commons Collections UnmodifiableMap.java source code

/*
 *  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 <code>Map to ensure it can't be altered.
 * <p>
 * This class is Serializable from Commons Collections 3.1.
 *
 * @since Commons Collections 3.0
 * @version $Revision: 646777 $ $Date: 2008-04-10 13:33:15 +0100 (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);
    }

}

Other Commons Collections examples (source code examples)

Here is a short list of links related to this Commons Collections UnmodifiableMap.java source code file:



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