com.google.common.collect.ImmutableBiMap.java Source code

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Here is the source code for com.google.common.collect.ImmutableBiMap.java

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/*
 * Copyright (C) 2009 The Guava Authors
 *
 * 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 com.google.common.collect;

import static com.google.common.collect.CollectPreconditions.checkEntryNotNull;

import java.util.Comparator;
import java.util.Map;
import java.util.Map.Entry;

/**
 * GWT emulation of {@link ImmutableBiMap}.
 *
 * @author Hayward Chan
 */
public abstract class ImmutableBiMap<K, V> extends ForwardingImmutableMap<K, V> implements BiMap<K, V> {

    // Casting to any type is safe because the set will never hold any elements.
    @SuppressWarnings("unchecked")
    public static <K, V> ImmutableBiMap<K, V> of() {
        return (ImmutableBiMap<K, V>) RegularImmutableBiMap.EMPTY;
    }

    public static <K, V> ImmutableBiMap<K, V> of(K k1, V v1) {
        checkEntryNotNull(k1, v1);
        return new SingletonImmutableBiMap<K, V>(k1, v1);
    }

    public static <K, V> ImmutableBiMap<K, V> of(K k1, V v1, K k2, V v2) {
        return new RegularImmutableBiMap<K, V>(ImmutableMap.of(k1, v1, k2, v2));
    }

    public static <K, V> ImmutableBiMap<K, V> of(K k1, V v1, K k2, V v2, K k3, V v3) {
        return new RegularImmutableBiMap<K, V>(ImmutableMap.of(k1, v1, k2, v2, k3, v3));
    }

    public static <K, V> ImmutableBiMap<K, V> of(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4) {
        return new RegularImmutableBiMap<K, V>(ImmutableMap.of(k1, v1, k2, v2, k3, v3, k4, v4));
    }

    public static <K, V> ImmutableBiMap<K, V> of(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5) {
        return new RegularImmutableBiMap<K, V>(ImmutableMap.of(k1, v1, k2, v2, k3, v3, k4, v4, k5, v5));
    }

    public static <K, V> Builder<K, V> builder() {
        return new Builder<K, V>();
    }

    public static final class Builder<K, V> extends ImmutableMap.Builder<K, V> {

        public Builder() {
        }

        Builder(int initCapacity) {
            super(initCapacity);
        }

        @Override
        public Builder<K, V> put(K key, V value) {
            super.put(key, value);
            return this;
        }

        @Override
        public Builder<K, V> put(Map.Entry<? extends K, ? extends V> entry) {
            super.put(entry);
            return this;
        }

        @Override
        public Builder<K, V> putAll(Map<? extends K, ? extends V> map) {
            super.putAll(map);
            return this;
        }

        @Override
        public Builder<K, V> putAll(Iterable<? extends Entry<? extends K, ? extends V>> entries) {
            super.putAll(entries);
            return this;
        }

        public Builder<K, V> orderEntriesByValue(Comparator<? super V> valueComparator) {
            super.orderEntriesByValue(valueComparator);
            return this;
        }

        @Override
        public ImmutableBiMap<K, V> build() {
            ImmutableMap<K, V> map = super.build();
            if (map.isEmpty()) {
                return of();
            }
            return new RegularImmutableBiMap<K, V>(super.build());
        }
    }

    public static <K, V> ImmutableBiMap<K, V> copyOf(Map<? extends K, ? extends V> map) {
        if (map instanceof ImmutableBiMap) {
            @SuppressWarnings("unchecked") // safe since map is not writable
            ImmutableBiMap<K, V> bimap = (ImmutableBiMap<K, V>) map;
            return bimap;
        }

        if (map.isEmpty()) {
            return of();
        }

        ImmutableMap<K, V> immutableMap = ImmutableMap.copyOf(map);
        return new RegularImmutableBiMap<K, V>(immutableMap);
    }

    public static <K, V> ImmutableBiMap<K, V> copyOf(Iterable<? extends Entry<? extends K, ? extends V>> entries) {
        return new Builder<K, V>().putAll(entries).build();
    }

    ImmutableBiMap(Map<K, V> delegate) {
        super(delegate);
    }

    public abstract ImmutableBiMap<V, K> inverse();

    @Override
    public ImmutableSet<V> values() {
        return inverse().keySet();
    }

    public final V forcePut(K key, V value) {
        throw new UnsupportedOperationException();
    }
}