com.liferay.portal.kernel.util.ClassLoaderPool Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of com.liferay.portal.kernel Show documentation

Contains interfaces for the portal services. Interfaces are only loaded by the global class loader and are shared by all plugins.

There is a newer version: 156.0.0

Show newest version

/**
 * 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.security.pacl.permission.PortalRuntimePermission;

import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

/**
 * Maps servlet context names to/from the servlet context's class loader.
 *
 * @author Shuyang Zhou
 */
public class ClassLoaderPool {

	/**
	 * Returns the class loader associated with the context name.
	 *
	 * 
	 * If no class loader is found for the context name, the thread's context
	 * class loader is returned as a fallback.
	 * 
	 *
	 * @param  contextName the servlet context's name
	 * @return the class loader associated with the context name
	 */
	public static ClassLoader getClassLoader(String contextName) {
		PortalRuntimePermission.checkGetBeanProperty(ClassLoaderPool.class);

		ClassLoader classLoader = null;

		if ((contextName != null) && !contextName.equals(StringPool.NULL)) {
			classLoader = _classLoaders.get(contextName);
		}

		if (classLoader == null) {
			Thread currentThread = Thread.currentThread();

			classLoader = currentThread.getContextClassLoader();
		}

		return classLoader;
	}

	/**
	 * Returns the context name associated with the class loader.
	 *
	 * 
	 * If the class loader is null or if no context name is
	 * associated with the class loader, {@link
	 * com.liferay.portal.kernel.util.StringPool#NULL} is returned.
	 * 
	 *
	 * @param  classLoader the class loader
	 * @return the context name associated with the class loader
	 */
	public static String getContextName(ClassLoader classLoader) {
		if (classLoader == null) {
			return StringPool.NULL;
		}

		String contextName = _contextNames.get(classLoader);

		if (contextName == null) {
			contextName = StringPool.NULL;
		}

		return contextName;
	}

	public static void register(String contextName, ClassLoader classLoader) {
		PortalRuntimePermission.checkGetBeanProperty(ClassLoaderPool.class);

		_classLoaders.put(contextName, classLoader);
		_contextNames.put(classLoader, contextName);
	}

	public static void unregister(ClassLoader classLoader) {
		PortalRuntimePermission.checkGetBeanProperty(ClassLoaderPool.class);

		String contextName = _contextNames.remove(classLoader);

		if (contextName != null) {
			_classLoaders.remove(contextName);
		}
	}

	public static void unregister(String contextName) {
		PortalRuntimePermission.checkGetBeanProperty(ClassLoaderPool.class);

		ClassLoader classLoader = _classLoaders.remove(contextName);

		if (classLoader != null) {
			_contextNames.remove(classLoader);
		}
	}

	private static final Map _classLoaders =
		new ConcurrentHashMap<>();
	private static final Map _contextNames =
		new ConcurrentHashMap<>();

}