/*
* Copyright (C) 2007 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.base.Preconditions.checkArgument;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.EnumMap;
import java.util.Map;
/**
* A {@code BiMap} backed by two {@code EnumMap} instances. Null keys and values
* are not permitted. An {@code EnumBiMap} and its inverse are both
* serializable.
*
* @author Mike Bostock
* @since 2.0 (imported from Google Collections Library)
*/
@GwtCompatible(emulated = true)
public final class EnumBiMap<K extends Enum<K>, V extends Enum<V>>
extends AbstractBiMap<K, V> {
private transient Class<K> keyType;
private transient Class<V> valueType;
/**
* Returns a new, empty {@code EnumBiMap} using the specified key and value
* types.
*
* @param keyType the key type
* @param valueType the value type
*/
public static <K extends Enum<K>, V extends Enum<V>> EnumBiMap<K, V>
create(Class<K> keyType, Class<V> valueType) {
return new EnumBiMap<K, V>(keyType, valueType);
}
/**
* Returns a new bimap with the same mappings as the specified map. If the
* specified map is an {@code EnumBiMap}, the new bimap has the same types as
* the provided map. Otherwise, the specified map must contain at least one
* mapping, in order to determine the key and value types.
*
* @param map the map whose mappings are to be placed in this map
* @throws IllegalArgumentException if map is not an {@code EnumBiMap}
* instance and contains no mappings
*/
public static <K extends Enum<K>, V extends Enum<V>> EnumBiMap<K, V>
create(Map<K, V> map) {
EnumBiMap<K, V> bimap = create(inferKeyType(map), inferValueType(map));
bimap.putAll(map);
return bimap;
}
private EnumBiMap(Class<K> keyType, Class<V> valueType) {
super(WellBehavedMap.wrap(new EnumMap<K, V>(keyType)),
WellBehavedMap.wrap(new EnumMap<V, K>(valueType)));
this.keyType = keyType;
this.valueType = valueType;
}
static <K extends Enum<K>> Class<K> inferKeyType(Map<K, ?> map) {
if (map instanceof EnumBiMap) {
return ((EnumBiMap<K, ?>) map).keyType();
}
if (map instanceof EnumHashBiMap) {
return ((EnumHashBiMap<K, ?>) map).keyType();
}
checkArgument(!map.isEmpty());
return map.keySet().iterator().next().getDeclaringClass();
}
private static <V extends Enum<V>> Class<V> inferValueType(Map<?, V> map) {
if (map instanceof EnumBiMap) {
return ((EnumBiMap<?, V>) map).valueType;
}
checkArgument(!map.isEmpty());
return map.values().iterator().next().getDeclaringClass();
}
/** Returns the associated key type. */
public Class<K> keyType() {
return keyType;
}
/** Returns the associated value type. */
public Class<V> valueType() {
return valueType;
}
/**
* @serialData the key class, value class, number of entries, first key, first
* value, second key, second value, and so on.
*/
@GwtIncompatible("java.io.ObjectOutputStream")
private void writeObject(ObjectOutputStream stream) throws IOException {
stream.defaultWriteObject();
stream.writeObject(keyType);
stream.writeObject(valueType);
Serialization.writeMap(this, stream);
}
@SuppressWarnings("unchecked") // reading fields populated by writeObject
@GwtIncompatible("java.io.ObjectInputStream")
private void readObject(ObjectInputStream stream)
throws IOException, ClassNotFoundException {
stream.defaultReadObject();
keyType = (Class<K>) stream.readObject();
valueType = (Class<V>) stream.readObject();
setDelegates(
WellBehavedMap.wrap(new EnumMap<K, V>(keyType)),
WellBehavedMap.wrap(new EnumMap<V, K>(valueType)));
Serialization.populateMap(this, stream);
}
@GwtIncompatible("not needed in emulated source.")
private static final long serialVersionUID = 0;
}
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