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.core.appender.routing; 018 019 import org.apache.logging.log4j.core.Appender; 020 import org.apache.logging.log4j.core.Filter; 021 import org.apache.logging.log4j.core.LogEvent; 022 import org.apache.logging.log4j.core.appender.AbstractAppender; 023 import org.apache.logging.log4j.core.appender.rewrite.RewritePolicy; 024 import org.apache.logging.log4j.core.config.AppenderControl; 025 import org.apache.logging.log4j.core.config.Configuration; 026 import org.apache.logging.log4j.core.config.Node; 027 import org.apache.logging.log4j.core.config.plugins.Plugin; 028 import org.apache.logging.log4j.core.config.plugins.PluginAttr; 029 import org.apache.logging.log4j.core.config.plugins.PluginConfiguration; 030 import org.apache.logging.log4j.core.config.plugins.PluginElement; 031 import org.apache.logging.log4j.core.config.plugins.PluginFactory; 032 033 import java.util.Map; 034 import java.util.concurrent.ConcurrentHashMap; 035 import java.util.concurrent.ConcurrentMap; 036 037 /** 038 * This Appender "routes" between various Appenders, some of which can be references to 039 * Appenders defined earlier in the configuration while others can be dynamically created 040 * within this Appender as required. Routing is achieved by specifying a pattern on 041 * the Routing appender declaration. The pattern should contain one or more substitution patterns of 042 * the form "$${[key:]token}". The pattern will be resolved each time the Appender is called using 043 * the built in StrSubstitutor and the StrLookup plugin that matches the specified key. 044 */ 045 @Plugin(name = "Routing", type = "Core", elementType = "appender", printObject = true) 046 public final class RoutingAppender extends AbstractAppender { 047 private static final String DEFAULT_KEY = "ROUTING_APPENDER_DEFAULT"; 048 private final Routes routes; 049 private final Route defaultRoute; 050 private final Configuration config; 051 private final ConcurrentMap<String, AppenderControl> appenders = new ConcurrentHashMap<String, AppenderControl>(); 052 private final RewritePolicy rewritePolicy; 053 054 private RoutingAppender(final String name, final Filter filter, final boolean handleException, final Routes routes, 055 final RewritePolicy rewritePolicy, final Configuration config) { 056 super(name, filter, null, handleException); 057 this.routes = routes; 058 this.config = config; 059 this.rewritePolicy = rewritePolicy; 060 Route defRoute = null; 061 for (final Route route : routes.getRoutes()) { 062 if (route.getKey() == null) { 063 if (defRoute == null) { 064 defRoute = route; 065 } else { 066 error("Multiple default routes. Route " + route.toString() + " will be ignored"); 067 } 068 } 069 } 070 defaultRoute = defRoute; 071 } 072 073 @Override 074 public void start() { 075 final Map<String, Appender<?>> map = config.getAppenders(); 076 // Register all the static routes. 077 for (final Route route : routes.getRoutes()) { 078 if (route.getAppenderRef() != null) { 079 final Appender appender = map.get(route.getAppenderRef()); 080 if (appender != null) { 081 final String key = route == defaultRoute ? DEFAULT_KEY : route.getKey(); 082 appenders.put(key, new AppenderControl(appender, null, null)); 083 } else { 084 LOGGER.error("Appender " + route.getAppenderRef() + " cannot be located. Route ignored"); 085 } 086 } 087 } 088 super.start(); 089 } 090 091 @Override 092 public void stop() { 093 super.stop(); 094 final Map<String, Appender<?>> map = config.getAppenders(); 095 for (final Map.Entry<String, AppenderControl> entry : appenders.entrySet()) { 096 final String name = entry.getValue().getAppender().getName(); 097 if (!map.containsKey(name)) { 098 entry.getValue().getAppender().stop(); 099 } 100 } 101 } 102 103 public void append(LogEvent event) { 104 if (rewritePolicy != null) { 105 event = rewritePolicy.rewrite(event); 106 } 107 final String key = config.getSubst().replace(event, routes.getPattern()); 108 final AppenderControl control = getControl(key, event); 109 if (control != null) { 110 control.callAppender(event); 111 } 112 } 113 114 private synchronized AppenderControl getControl(final String key, final LogEvent event) { 115 AppenderControl control = appenders.get(key); 116 if (control != null) { 117 return control; 118 } 119 Route route = null; 120 for (final Route r : routes.getRoutes()) { 121 if (r.getAppenderRef() == null && key.equals(r.getKey())) { 122 route = r; 123 break; 124 } 125 } 126 if (route == null) { 127 route = defaultRoute; 128 } 129 if (route != null) { 130 final Appender app = createAppender(route, event); 131 if (app == null) { 132 return null; 133 } 134 control = new AppenderControl(app, null, null); 135 appenders.put(key, control); 136 } 137 138 return control; 139 } 140 141 private Appender createAppender(final Route route, final LogEvent event) { 142 final Node routeNode = route.getNode(); 143 for (final Node node : routeNode.getChildren()) { 144 if (node.getType().getElementName().equals("appender")) { 145 final Node appNode = new Node(node); 146 config.createConfiguration(appNode, event); 147 if (appNode.getObject() instanceof Appender) { 148 final Appender app = (Appender) appNode.getObject(); 149 app.start(); 150 return app; 151 } 152 LOGGER.error("Unable to create Appender of type " + node.getName()); 153 return null; 154 } 155 } 156 LOGGER.error("No Appender was configured for route " + route.getKey()); 157 return null; 158 } 159 160 /** 161 * Create a RoutingAppender. 162 * @param name The name of the Appender. 163 * @param suppress "true" if exceptions should be hidden from the application, "false" otherwise. 164 * The default is "true". 165 * @param routes The routing definitions. 166 * @param config The Configuration (automatically added by the Configuration). 167 * @param rewritePolicy A RewritePolicy, if any. 168 * @param filter A Filter to restrict events processed by the Appender or null. 169 * @return The RoutingAppender 170 */ 171 @PluginFactory 172 public static RoutingAppender createAppender(@PluginAttr("name") final String name, 173 @PluginAttr("suppressExceptions") final String suppress, 174 @PluginElement("routes") final Routes routes, 175 @PluginConfiguration final Configuration config, 176 @PluginElement("rewritePolicy") final RewritePolicy rewritePolicy, 177 @PluginElement("filters") final Filter filter) { 178 179 final boolean handleExceptions = suppress == null ? true : Boolean.valueOf(suppress); 180 181 if (name == null) { 182 LOGGER.error("No name provided for RoutingAppender"); 183 return null; 184 } 185 if (routes == null) { 186 LOGGER.error("No routes defined for RoutingAppender"); 187 return null; 188 } 189 return new RoutingAppender(name, filter, handleExceptions, routes, rewritePolicy, config); 190 } 191 }