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 */
017 package org.apache.logging.log4j.web.appender;
018
019 import java.io.Serializable;
020 import javax.servlet.ServletContext;
021
022 import org.apache.logging.log4j.core.Filter;
023 import org.apache.logging.log4j.core.Layout;
024 import org.apache.logging.log4j.core.LogEvent;
025 import org.apache.logging.log4j.core.appender.AbstractAppender;
026 import org.apache.logging.log4j.core.config.plugins.Plugin;
027 import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
028 import org.apache.logging.log4j.core.config.plugins.PluginElement;
029 import org.apache.logging.log4j.core.config.plugins.PluginFactory;
030 import org.apache.logging.log4j.core.config.plugins.validation.constraints.Required;
031 import org.apache.logging.log4j.core.layout.AbstractStringLayout;
032 import org.apache.logging.log4j.core.layout.PatternLayout;
033 import 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)
039 public class ServletAppender extends AbstractAppender {
040
041 private static final long serialVersionUID = 1L;
042
043 private final ServletContext servletContext;
044
045 private ServletAppender(final String name, final AbstractStringLayout layout, final Filter filter,
046 final ServletContext servletContext, final boolean ignoreExceptions) {
047 super(name, filter, layout, ignoreExceptions);
048 this.servletContext = servletContext;
049 }
050
051 @Override
052 public void append(final LogEvent event) {
053 servletContext.log(((AbstractStringLayout) getLayout()).toSerializable(event));
054 }
055
056 /**
057 * Create a Servlet Appender.
058 * @param layout The layout to use (required). Must extend {@link AbstractStringLayout}.
059 * @param filter The Filter or null.
060 * @param name The name of the Appender (required).
061 * @param ignoreExceptions If {@code true} (default) exceptions encountered when appending events are logged;
062 * otherwise they are propagated to the caller.
063 * @return The ServletAppender.
064 */
065 @PluginFactory
066 public static ServletAppender createAppender(
067 @PluginElement("Layout") Layout<? extends Serializable> layout,
068 @PluginElement("Filter") final Filter filter,
069 @PluginAttribute("name")
070 @Required(message = "No name provided for ServletAppender")
071 final String name,
072 @PluginAttribute(value = "ignoreExceptions", defaultBoolean = true) final boolean ignoreExceptions) {
073 final ServletContext servletContext = WebLoggerContextUtils.getServletContext();
074 if (servletContext == null) {
075 LOGGER.error("No servlet context is available");
076 return null;
077 }
078 if (layout == null) {
079 layout = PatternLayout.createDefaultLayout();
080 } else if (!(layout instanceof AbstractStringLayout)) {
081 LOGGER.error("Layout must be a StringLayout to log to ServletContext");
082 return null;
083 }
084 return new ServletAppender(name, (AbstractStringLayout) layout, filter, servletContext, ignoreExceptions);
085 }
086
087 }