Update #0 - First Release

sources/main/java/com/google/common/collect/EnumBiMap.java

@@ -0,0 +1,146 @@
+/*
+ * 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 static com.google.common.base.Preconditions.checkNotNull;
+
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.util.EnumMap;
+import java.util.Map;
+
+import com.google.common.annotations.GwtCompatible;
+import com.google.common.annotations.GwtIncompatible;
+
+/**
+ * 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.
+ * 
+ * <p>
+ * See the Guava User Guide article on <a href=
+ * "http://code.google.com/p/guava-libraries/wiki/NewCollectionTypesExplained#BiMap">
+ * {@code BiMap}</a>.
+ *
+ * @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;
+	}
+
+	@Override
+	K checkKey(K key) {
+		return checkNotNull(key);
+	}
+
+	@Override
+	V checkValue(V value) {
+		return checkNotNull(value);
+	}
+
+	/**
+	 * @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;
+}