ImmutableMap.java

/*
 *  Copyright 2013 Samppa Saarela
 *
 * Licensed 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.javersion.util;

import java.util.AbstractMap;
import java.util.AbstractSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

import javax.annotation.concurrent.Immutable;

@Immutable
class ImmutableMap<K, V> extends AbstractMap<K, V> {

    private final PersistentMap<K, V> map;

    ImmutableMap(PersistentMap<K, V> map) {
        this.map = Check.notNull(map, "map");
    }

    public PersistentMap<K, V> getPersistentMap() {
        return map;
    }

    @Override
    public int size() {
        return map.size();
    }

    @Override
    public boolean containsKey(Object key) {
        return map.containsKey(key);
    }

    @Override
    public V get(Object key) {
        return map.get(key);
    }

    @Override
    public Set<Map.Entry<K, V>> entrySet() {
        return new AbstractSet<Map.Entry<K, V>>() {

            @Override
            public Iterator<Map.Entry<K, V>> iterator() {
                return map.iterator();
            }

            @Override
            public int size() {
                return map.size();
            }
        };
    }

    @Override
    public V put(final K key, final V value) {
        throw new UnsupportedOperationException();
    }

    @Override
    public V remove(final Object key) {
        throw new UnsupportedOperationException();
    }

    @Override
    public void putAll(final Map<? extends K, ? extends V> m) {
        throw new UnsupportedOperationException();
    }

    @Override
    public void clear() {
        throw new UnsupportedOperationException();
    }

}