/**
 * 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.instantiator.basic;

import java.io.ObjectStreamClass;
import java.lang.reflect.Method;

import ext.test4j.objenesis.ObjenesisException;
import ext.test4j.objenesis.instantiator.ObjectInstantiator;

/**
 * Instantiates a class by using reflection to make a call to private method
 * ObjectStreamClass.newInstance, present in many JVM implementations. This
 * instantiator will create classes in a way compatible with serialization,
 * calling the first non-serializable superclass' no-arg constructor.
 * 
 * @author Leonardo Mesquita
 * @see ObjectInstantiator
 * @see java.io.Serializable
 */
@SuppressWarnings("rawtypes")
public class ObjectStreamClassInstantiator implements ObjectInstantiator {

	private static Method newInstanceMethod;

	private static void initialize() {
		if (newInstanceMethod == null) {
			try {
				newInstanceMethod = ObjectStreamClass.class.getDeclaredMethod("newInstance", new Class[] {});
				newInstanceMethod.setAccessible(true);
			} catch (RuntimeException e) {
				throw new ObjenesisException(e);
			} catch (NoSuchMethodException e) {
				throw new ObjenesisException(e);
			}
		}
	}

	private final ObjectStreamClass objStreamClass;

	public ObjectStreamClassInstantiator(Class type) {
		initialize();
		objStreamClass = ObjectStreamClass.lookup(type);
	}

	public Object newInstance() {

		try {
			return newInstanceMethod.invoke(objStreamClass, new Object[] {});
		} catch (Exception e) {
			throw new ObjenesisException(e);
		}

	}

}