001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache license, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the license for the specific language governing permissions and 015 * limitations under the license. 016 */ 017package org.apache.logging.log4j.web.appender; 018 019import java.io.Serializable; 020import javax.servlet.ServletContext; 021 022import org.apache.logging.log4j.core.Filter; 023import org.apache.logging.log4j.core.Layout; 024import org.apache.logging.log4j.core.LogEvent; 025import org.apache.logging.log4j.core.appender.AbstractAppender; 026import org.apache.logging.log4j.core.config.plugins.Plugin; 027import org.apache.logging.log4j.core.config.plugins.PluginAttribute; 028import org.apache.logging.log4j.core.config.plugins.PluginElement; 029import org.apache.logging.log4j.core.config.plugins.PluginFactory; 030import org.apache.logging.log4j.core.config.plugins.validation.constraints.Required; 031import org.apache.logging.log4j.core.layout.AbstractStringLayout; 032import org.apache.logging.log4j.core.layout.PatternLayout; 033import org.apache.logging.log4j.web.WebLoggerContextUtils; 034 035/** 036 * Logs using the ServletContext's log method 037 */ 038@Plugin(name = "Servlet", category = "Core", elementType = "appender", printObject = true) 039public class ServletAppender extends AbstractAppender { 040 041 private final ServletContext servletContext; 042 043 private ServletAppender(final String name, final AbstractStringLayout layout, final Filter filter, 044 final ServletContext servletContext, final boolean ignoreExceptions) { 045 super(name, filter, layout, ignoreExceptions); 046 this.servletContext = servletContext; 047 } 048 049 @Override 050 public void append(final LogEvent event) { 051 servletContext.log(((AbstractStringLayout) getLayout()).toSerializable(event)); 052 } 053 054 /** 055 * Create a Servlet Appender. 056 * @param layout The layout to use (required). Must extend {@link AbstractStringLayout}. 057 * @param filter The Filter or null. 058 * @param name The name of the Appender (required). 059 * @param ignoreExceptions If {@code true} (default) exceptions encountered when appending events are logged; 060 * otherwise they are propagated to the caller. 061 * @return The ServletAppender. 062 */ 063 @PluginFactory 064 public static ServletAppender createAppender( 065 @PluginElement("Layout") Layout<? extends Serializable> layout, 066 @PluginElement("Filter") final Filter filter, 067 @PluginAttribute("name") @Required(message = "No name provided for ServletAppender") final String name, 068 @PluginAttribute(value = "ignoreExceptions", defaultBoolean = true) final boolean ignoreExceptions) { 069 final ServletContext servletContext = WebLoggerContextUtils.getServletContext(); 070 if (servletContext == null) { 071 LOGGER.error("No servlet context is available"); 072 return null; 073 } 074 if (layout == null) { 075 layout = PatternLayout.createDefaultLayout(); 076 } else if (!(layout instanceof AbstractStringLayout)) { 077 LOGGER.error("Layout must be a StringLayout to log to ServletContext"); 078 return null; 079 } 080 return new ServletAppender(name, (AbstractStringLayout) layout, filter, servletContext, ignoreExceptions); 081 } 082 083}