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/**
 * Copyright 2006-2009 the original author or 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 ext.test4j.objenesis;

import java.util.HashMap;
import java.util.Map;

import ext.test4j.objenesis.instantiator.ObjectInstantiator;
import ext.test4j.objenesis.strategy.InstantiatorStrategy;

/**
 * Base class to extend if you want to have a class providing your own default
 * strategy. Can also be instantiated directly.
 * 
 * @author Henri Tremblay
 */
@SuppressWarnings({ "rawtypes", "unchecked" })
public class ObjenesisBase implements Objenesis {

	/** Strategy used by this Objenesi implementation to create classes */
	protected final InstantiatorStrategy strategy;

	/** Strategy cache. Key = Class, Value = InstantiatorStrategy */
	protected Map cache;

	/**
	 * Constructor allowing to pick a strategy and using cache
	 * 
	 * @param strategy
	 *            Strategy to use
	 */
	public ObjenesisBase(InstantiatorStrategy strategy) {
		this(strategy, true);
	}

	/**
	 * Flexible constructor allowing to pick the strategy and if caching should
	 * be used
	 * 
	 * @param strategy
	 *            Strategy to use
	 * @param useCache
	 *            If {@link ObjectInstantiator}s should be cached
	 */
	public ObjenesisBase(InstantiatorStrategy strategy, boolean useCache) {
		if (strategy == null) {
			throw new IllegalArgumentException("A strategy can't be null");
		}
		this.strategy = strategy;
		this.cache = useCache ? new HashMap() : null;
	}

	public String toString() {
		return getClass().getName() + " using " + strategy.getClass().getName()
				+ (cache == null ? " without" : " with") + " caching";
	}

	/**
	 * Will create a new object without any constructor being called
	 * 
	 * @param clazz
	 *            Class to instantiate
	 * @return New instance of clazz
	 */
	public Object newInstance(Class clazz) {
		return getInstantiatorOf(clazz).newInstance();
	}

	/**
	 * Will pick the best instantiator for the provided class. If you need to
	 * create a lot of instances from the same class, it is way more efficient
	 * to create them from the same ObjectInstantiator than calling
	 * {@link #newInstance(Class)}.
	 * 
	 * @param clazz
	 *            Class to instantiate
	 * @return Instantiator dedicated to the class
	 */
	public synchronized ObjectInstantiator getInstantiatorOf(Class clazz) {
		if (cache == null) {
			return strategy.newInstantiatorOf(clazz);
		}
		ObjectInstantiator instantiator = (ObjectInstantiator) cache.get(clazz.getName());
		if (instantiator == null) {
			instantiator = strategy.newInstantiatorOf(clazz);
			cache.put(clazz.getName(), instantiator);
		}
		return instantiator;
	}

}