ClassLoaderProxy.java

/**
 * Copyright (c) 2000-present Liferay, Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
 * details.
 */

package com.liferay.portal.kernel.util;

import com.liferay.portal.kernel.io.unsync.UnsyncByteArrayInputStream;
import com.liferay.portal.kernel.io.unsync.UnsyncByteArrayOutputStream;
import com.liferay.portal.kernel.log.Log;
import com.liferay.portal.kernel.log.LogFactoryUtil;

import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

/**
 * @author Brian Wing Shun Chan
 */
public class ClassLoaderProxy {

	public ClassLoaderProxy(Object obj, ClassLoader classLoader) {
		this(obj, obj.getClass().getName(), classLoader);
	}

	public ClassLoaderProxy(
		Object obj, String className, ClassLoader classLoader) {

		_obj = obj;
		_className = className;
		_classLoader = classLoader;
	}

	public ClassLoader getClassLoader() {
		return _classLoader;
	}

	public String getClassName() {
		return _className;
	}

	public Object invoke(MethodHandler methodHandler) throws Throwable {
		Thread currentThread = Thread.currentThread();

		ClassLoader contextClassLoader = currentThread.getContextClassLoader();

		try {
			currentThread.setContextClassLoader(_classLoader);

			return _invoke(methodHandler);
		}
		catch (InvocationTargetException ite) {
			throw translateThrowable(ite.getCause(), contextClassLoader);
		}
		catch (Throwable t) {
			_log.error(t, t);

			throw t;
		}
		finally {
			currentThread.setContextClassLoader(contextClassLoader);
		}
	}

	protected Throwable translateThrowable(
		Throwable throwable, ClassLoader contextClassLoader) {

		try {
			UnsyncByteArrayOutputStream unsyncByteArrayOutputStream =
				new UnsyncByteArrayOutputStream();

			try (ObjectOutputStream objectOutputStream = new ObjectOutputStream(
					unsyncByteArrayOutputStream)) {

				objectOutputStream.writeObject(throwable);

				objectOutputStream.flush();
			}

			UnsyncByteArrayInputStream unsyncByteArrayInputStream =
				new UnsyncByteArrayInputStream(
					unsyncByteArrayOutputStream.unsafeGetByteArray(), 0,
					unsyncByteArrayOutputStream.size());

			try (ObjectInputStream objectInputStream =
					new ClassLoaderObjectInputStream(
						unsyncByteArrayInputStream, contextClassLoader)) {

				return (Throwable)objectInputStream.readObject();
			}
		}
		catch (Throwable throwable2) {
			_log.error(throwable2, throwable2);

			return throwable2;
		}
	}

	private Object _invoke(MethodHandler methodHandler) throws Exception {
		try {
			return methodHandler.invoke(_obj);
		}
		catch (NoSuchMethodException nsme) {
			MethodKey methodKey = methodHandler.getMethodKey();

			String name = methodKey.getMethodName();

			Class<?>[] parameterTypes = methodKey.getParameterTypes();

			Class<?> clazz = Class.forName(_className, true, _classLoader);

			for (Method method : clazz.getMethods()) {
				String curName = method.getName();
				Class<?>[] curParameterTypes = method.getParameterTypes();

				if (!curName.equals(name) ||
					(curParameterTypes.length != parameterTypes.length)) {

					continue;
				}

				boolean correctParams = true;

				for (int j = 0; j < parameterTypes.length; j++) {
					Class<?> a = parameterTypes[j];
					Class<?> b = curParameterTypes[j];

					if (!ClassUtil.isSubclass(a, b.getName())) {
						correctParams = false;

						break;
					}
				}

				if (correctParams) {
					return method.invoke(_obj, methodHandler.getArguments());
				}
			}

			throw nsme;
		}
	}

	private static final Log _log = LogFactoryUtil.getLog(
		ClassLoaderProxy.class);

	private final ClassLoader _classLoader;
	private final String _className;
	private final Object _obj;

}