| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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 org.apache.logging.log4j.web; |
| |
| import java.util.AbstractMap; |
| import java.util.Map; |
| import java.util.concurrent.locks.Lock; |
| import java.util.concurrent.locks.ReentrantLock; |
| import javax.servlet.ServletContext; |
| |
| import org.apache.logging.log4j.LogManager; |
| import org.apache.logging.log4j.core.LoggerContext; |
| import org.apache.logging.log4j.core.impl.ContextAnchor; |
| |
| /** |
| * Convenience methods for retrieving the {@link org.apache.logging.log4j.core.LoggerContext} associated with a |
| * particular ServletContext. These methods are most particularly useful for asynchronous servlets where the |
| * Thread Context ClassLoader (TCCL) is potentially different from the TCCL used by the |
| * Servlet container that bootstrapped Log4j. |
| * |
| * @since 2.0.1 |
| */ |
| public final class WebLoggerContextUtils { |
| private WebLoggerContextUtils() { |
| } |
| |
| private static final Lock WEB_SUPPORT_LOOKUP = new ReentrantLock(); |
| private static final String SERVLET_CONTEXT = "__SERVLET_CONTEXT__"; |
| |
| /** |
| * Finds the main {@link org.apache.logging.log4j.core.LoggerContext} configured for the given ServletContext. |
| * |
| * @param servletContext the ServletContext to locate a LoggerContext for |
| * @return the LoggerContext for the given ServletContext |
| * @since 2.0.1 |
| */ |
| public static LoggerContext getWebLoggerContext(final ServletContext servletContext) { |
| return (LoggerContext) servletContext.getAttribute(Log4jWebSupport.CONTEXT_ATTRIBUTE); |
| } |
| |
| /** |
| * Finds the main {@link org.apache.logging.log4j.core.LoggerContext} configured for the given ServletContext. |
| * |
| * @param servletContext the ServletContext to locate a LoggerContext for |
| * @return the LoggerContext for the given ServletContext or {@code null} if none was set |
| * @throws java.lang.IllegalStateException if no LoggerContext could be found on the given ServletContext |
| * @since 2.0.1 |
| */ |
| public static LoggerContext getRequiredWebLoggerContext(final ServletContext servletContext) { |
| final LoggerContext loggerContext = getWebLoggerContext(servletContext); |
| if (loggerContext == null) { |
| throw new IllegalStateException( |
| "No LoggerContext found in ServletContext attribute " + Log4jWebSupport.CONTEXT_ATTRIBUTE); |
| } |
| return loggerContext; |
| } |
| |
| /** |
| * Finds or initializes the {@link org.apache.logging.log4j.web.Log4jWebLifeCycle} singleton for the given |
| * ServletContext. |
| * |
| * @param servletContext the ServletContext to get the Log4jWebLifeCycle for |
| * @return the Log4jWebLifeCycle for the given ServletContext |
| * @since 2.0.1 |
| */ |
| public static Log4jWebLifeCycle getWebLifeCycle(final ServletContext servletContext) { |
| WEB_SUPPORT_LOOKUP.lock(); |
| try { |
| Log4jWebLifeCycle webLifeCycle = (Log4jWebLifeCycle) servletContext.getAttribute( |
| Log4jWebSupport.SUPPORT_ATTRIBUTE); |
| if (webLifeCycle == null) { |
| webLifeCycle = Log4jWebInitializerImpl.initialize(servletContext); |
| } |
| return webLifeCycle; |
| } finally { |
| WEB_SUPPORT_LOOKUP.unlock(); |
| } |
| } |
| |
| /** |
| * Wraps a Runnable instance by setting its thread context {@link org.apache.logging.log4j.core.LoggerContext} |
| * before execution and clearing it after execution. |
| * |
| * @param servletContext the ServletContext to locate a LoggerContext for |
| * @param runnable the Runnable to wrap execution for |
| * @return a wrapped Runnable |
| * @since 2.0.1 |
| */ |
| public static Runnable wrapExecutionContext(final ServletContext servletContext, final Runnable runnable) { |
| return () -> { |
| final Log4jWebSupport webSupport = getWebLifeCycle(servletContext); |
| webSupport.setLoggerContext(); |
| try { |
| runnable.run(); |
| } finally { |
| webSupport.clearLoggerContext(); |
| } |
| }; |
| } |
| |
| public static Map.Entry<String, Object> createExternalEntry(ServletContext servletContext) { |
| return new AbstractMap.SimpleEntry<>(SERVLET_CONTEXT, servletContext); |
| } |
| |
| public static void setServletContext(LoggerContext lc, ServletContext servletContext) { |
| if (lc != null) { |
| lc.putObject(SERVLET_CONTEXT, servletContext); |
| } |
| } |
| |
| /** |
| * Gets the current {@link ServletContext} if it has already been assigned to a LoggerContext's external context. |
| * |
| * @return the current ServletContext attached to a LoggerContext or {@code null} if none could be found |
| * @since 2.1 |
| */ |
| public static ServletContext getServletContext() { |
| org.apache.logging.log4j.spi.LoggerContext lc = ContextAnchor.THREAD_CONTEXT.get(); |
| if (lc == null) { |
| lc = LogManager.getContext(false); |
| } |
| Object obj = lc != null ? lc.getObject(SERVLET_CONTEXT) : null; |
| if (obj instanceof ServletContext) { |
| return (ServletContext) obj; |
| } |
| return null; |
| } |
| } |