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Strategies for Java collections
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/* Copyright 2014 Sven van der Meer 
 *
 * 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 de.vandermeer.skb.collections;

import java.util.HashMap;
import java.util.Hashtable;
import java.util.IdentityHashMap;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.TreeMap;
import java.util.WeakHashMap;
import java.util.concurrent.ConcurrentHashMap;

/**
 * Strategies for maps.
 *
 * @author     Sven van der Meer <[email protected]>
 * @version    v0.0.4 build 150619 (19-Jun-15) for Java 1.8
 */
public enum MapStrategy implements IsMapStrategy {
	/** Default map, results in an HashMap */
	DEFAULT,

	/** HashMap from java-util. */
	HASH_MAP,

	/** Hashtable from java-util. */
	HASH_TABLE,

	/** LinkedHashMap from java-util. */
	LINKED_HASH_MAP,

	/** IdentityHashMap from java-util. */
	IDENTITY_HASH_MAP,

	/** ConcurrentHashMap from java-util. */
	CONCURRENT_HASH_MAP,

	/** WeakHashMap from java-util. */
	WEAK_HASH_MAP,

	/** TreeMap from java-util. */
	TREE_MAP,
	;

	/**
	 * Returns a new map for the used strategy (enum) for the given class T as map <String, T>.
	 * @param  class to be used for initialising the map
	 * @return new map for the given class
	 */
	@Override
	public  Map get(Class T) {
		switch(this){
			case LINKED_HASH_MAP:
				return new LinkedHashMap();
			case TREE_MAP:
				return new TreeMap();
			case HASH_TABLE:
				return new Hashtable();
			case IDENTITY_HASH_MAP:
				return new IdentityHashMap();
			case WEAK_HASH_MAP:
				return new WeakHashMap();
			case CONCURRENT_HASH_MAP:
				return new ConcurrentHashMap();
			case HASH_MAP:
			case DEFAULT:
			default:
				return new HashMap();
		}
	}

	/**
	 * Returns a new map view for the given map of type <String, T>.
	 * @param  type for the map values
	 * @param map input map
	 * @return new map view
	 */
	@Override
	public  Map get(Map map){
		Map ret;
		switch(this){
			case LINKED_HASH_MAP:
				ret = new LinkedHashMap(map);
				break;
			case TREE_MAP:
				ret = new TreeMap(map);
				break;
			case HASH_TABLE:
				ret = new Hashtable(map);
				break;
			case IDENTITY_HASH_MAP:
				ret = new IdentityHashMap(map);
				break;
			case WEAK_HASH_MAP:
				ret = new WeakHashMap(map);
				break;
			case CONCURRENT_HASH_MAP:
				ret = new ConcurrentHashMap(map);
				break;
			case HASH_MAP:
			case DEFAULT:
			default:
				ret = new HashMap(map);
				break;
	}
		return ret;
	}

	@Override
	public String toString() {
		return this.name();
	}
}