/*
* 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.core.appender.routing;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import org.apache.logging.log4j.core.Appender;
import org.apache.logging.log4j.core.Filter;
import org.apache.logging.log4j.core.LogEvent;
import org.apache.logging.log4j.core.appender.AbstractAppender;
import org.apache.logging.log4j.core.appender.rewrite.RewritePolicy;
import org.apache.logging.log4j.core.config.AppenderControl;
import org.apache.logging.log4j.core.config.Configuration;
import org.apache.logging.log4j.core.config.Node;
import org.apache.logging.log4j.core.config.plugins.Plugin;
import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
import org.apache.logging.log4j.core.config.plugins.PluginConfiguration;
import org.apache.logging.log4j.core.config.plugins.PluginElement;
import org.apache.logging.log4j.core.config.plugins.PluginFactory;
import org.apache.logging.log4j.core.util.Booleans;
/**
* This Appender "routes" between various Appenders, some of which can be references to
* Appenders defined earlier in the configuration while others can be dynamically created
* within this Appender as required. Routing is achieved by specifying a pattern on
* the Routing appender declaration. The pattern should contain one or more substitution patterns of
* the form "$${[key:]token}". The pattern will be resolved each time the Appender is called using
* the built in StrSubstitutor and the StrLookup plugin that matches the specified key.
*/
@Plugin(name = "Routing", category = "Core", elementType = "appender", printObject = true)
public final class RoutingAppender extends AbstractAppender {
private static final String DEFAULT_KEY = "ROUTING_APPENDER_DEFAULT";
private final Routes routes;
private final Route defaultRoute;
private final Configuration config;
private final ConcurrentMap<String, AppenderControl> appenders =
new ConcurrentHashMap<String, AppenderControl>();
private final RewritePolicy rewritePolicy;
private RoutingAppender(final String name, final Filter filter, final boolean ignoreExceptions, final Routes routes,
final RewritePolicy rewritePolicy, final Configuration config) {
super(name, filter, null, ignoreExceptions);
this.routes = routes;
this.config = config;
this.rewritePolicy = rewritePolicy;
Route defRoute = null;
for (final Route route : routes.getRoutes()) {
if (route.getKey() == null) {
if (defRoute == null) {
defRoute = route;
} else {
error("Multiple default routes. Route " + route.toString() + " will be ignored");
}
}
}
defaultRoute = defRoute;
}
@Override
public void start() {
// Register all the static routes.
for (final Route route : routes.getRoutes()) {
if (route.getAppenderRef() != null) {
final Appender appender = config.getAppender(route.getAppenderRef());
if (appender != null) {
final String key = route == defaultRoute ? DEFAULT_KEY : route.getKey();
appenders.put(key, new AppenderControl(appender, null, null));
} else {
LOGGER.error("Appender " + route.getAppenderRef() + " cannot be located. Route ignored");
}
}
}
super.start();
}
@Override
public void stop() {
super.stop();
final Map<String, Appender> map = config.getAppenders();
for (final Map.Entry<String, AppenderControl> entry : appenders.entrySet()) {
final String name = entry.getValue().getAppender().getName();
if (!map.containsKey(name)) {
entry.getValue().getAppender().stop();
}
}
}
@Override
public void append(LogEvent event) {
if (rewritePolicy != null) {
event = rewritePolicy.rewrite(event);
}
final String key = config.getStrSubstitutor().replace(event, routes.getPattern());
final AppenderControl control = getControl(key, event);
if (control != null) {
control.callAppender(event);
}
}
private synchronized AppenderControl getControl(final String key, final LogEvent event) {
AppenderControl control = appenders.get(key);
if (control != null) {
return control;
}
Route route = null;
for (final Route r : routes.getRoutes()) {
if (r.getAppenderRef() == null && key.equals(r.getKey())) {
route = r;
break;
}
}
if (route == null) {
route = defaultRoute;
control = appenders.get(DEFAULT_KEY);
if (control != null) {
return control;
}
}
if (route != null) {
final Appender app = createAppender(route, event);
if (app == null) {
return null;
}
control = new AppenderControl(app, null, null);
appenders.put(key, control);
}
return control;
}
private Appender createAppender(final Route route, final LogEvent event) {
final Node routeNode = route.getNode();
for (final Node node : routeNode.getChildren()) {
if (node.getType().getElementName().equals("appender")) {
final Node appNode = new Node(node);
config.createConfiguration(appNode, event);
if (appNode.getObject() instanceof Appender) {
final Appender app = (Appender) appNode.getObject();
app.start();
return app;
}
LOGGER.error("Unable to create Appender of type " + node.getName());
return null;
}
}
LOGGER.error("No Appender was configured for route " + route.getKey());
return null;
}
/**
* Create a RoutingAppender.
* @param name The name of the Appender.
* @param ignore If {@code "true"} (default) exceptions encountered when appending events are logged; otherwise
* they are propagated to the caller.
* @param routes The routing definitions.
* @param config The Configuration (automatically added by the Configuration).
* @param rewritePolicy A RewritePolicy, if any.
* @param filter A Filter to restrict events processed by the Appender or null.
* @return The RoutingAppender
*/
@PluginFactory
public static RoutingAppender createAppender(
@PluginAttribute("name") final String name,
@PluginAttribute("ignoreExceptions") final String ignore,
@PluginElement("Routes") final Routes routes,
@PluginConfiguration final Configuration config,
@PluginElement("RewritePolicy") final RewritePolicy rewritePolicy,
@PluginElement("Filters") final Filter filter) {
final boolean ignoreExceptions = Booleans.parseBoolean(ignore, true);
if (name == null) {
LOGGER.error("No name provided for RoutingAppender");
return null;
}
if (routes == null) {
LOGGER.error("No routes defined for RoutingAppender");
return null;
}
return new RoutingAppender(name, filter, ignoreExceptions, routes, rewritePolicy, config);
}
}