/*
* 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.rewrite;
import java.util.HashMap;
import java.util.Map;
import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.core.LogEvent;
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.PluginElement;
import org.apache.logging.log4j.core.config.plugins.PluginFactory;
import org.apache.logging.log4j.core.impl.Log4jLogEvent;
import org.apache.logging.log4j.core.util.KeyValuePair;
import org.apache.logging.log4j.message.MapMessage;
import org.apache.logging.log4j.message.Message;
import org.apache.logging.log4j.status.StatusLogger;
/**
* This policy modifies events by replacing or possibly adding keys and values to the MapMessage.
*/
@Plugin(name = "MapRewritePolicy", category = "Core", elementType = "rewritePolicy", printObject = true)
public final class MapRewritePolicy implements RewritePolicy {
/**
* Allow subclasses access to the status logger without creating another instance.
*/
protected static final Logger LOGGER = StatusLogger.getLogger();
private final Map<String, String> map;
private final Mode mode;
private MapRewritePolicy(final Map<String, String> map, final Mode mode) {
this.map = map;
this.mode = mode;
}
/**
* Rewrite the event.
* @param source a logging event that may be returned or
* used to create a new logging event.
* @return The LogEvent after rewriting.
*/
@Override
public LogEvent rewrite(final LogEvent source) {
final Message msg = source.getMessage();
if (msg == null || !(msg instanceof MapMessage)) {
return source;
}
final Map<String, String> newMap = new HashMap<String, String>(((MapMessage) msg).getData());
switch (mode) {
case Add: {
newMap.putAll(map);
break;
}
default: {
for (final Map.Entry<String, String> entry : map.entrySet()) {
if (newMap.containsKey(entry.getKey())) {
newMap.put(entry.getKey(), entry.getValue());
}
}
}
}
final MapMessage message = ((MapMessage) msg).newInstance(newMap);
if (source instanceof Log4jLogEvent) {
Log4jLogEvent event = (Log4jLogEvent) source;
return Log4jLogEvent.createEvent(event.getLoggerName(), event.getMarker(), event.getLoggerFqcn(),
event.getLevel(), message, event.getThrown(), event.getThrownProxy(), event.getContextMap(),
event.getContextStack(), event.getThreadName(), event.getSource(), event.getTimeMillis());
}
return new Log4jLogEvent(source.getLoggerName(), source.getMarker(), source.getLoggerFqcn(), source.getLevel(),
message, source.getThrown(), source.getContextMap(), source.getContextStack(), source.getThreadName(),
source.getSource(), source.getTimeMillis());
}
/**
* An enumeration to identify whether keys not in the MapMessage should be added or whether only existing
* keys should be updated.
*/
public enum Mode {
/**
* Keys should be added.
*/
Add,
/**
* Keys should be updated.
*/
Update
}
@Override
public String toString() {
final StringBuilder sb = new StringBuilder();
sb.append("mode=").append(mode);
sb.append(" {");
boolean first = true;
for (final Map.Entry<String, String> entry : map.entrySet()) {
if (!first) {
sb.append(", ");
}
sb.append(entry.getKey()).append('=').append(entry.getValue());
first = false;
}
sb.append('}');
return sb.toString();
}
/**
* The factory method to create the MapRewritePolicy.
* @param mode The string representation of the Mode.
* @param pairs key/value pairs for the new Map keys and values.
* @return The MapRewritePolicy.
*/
@PluginFactory
public static MapRewritePolicy createPolicy(
@PluginAttribute("mode") final String mode,
@PluginElement("KeyValuePair") final KeyValuePair[] pairs) {
Mode op;
if (mode == null) {
op = Mode.Add;
} else {
op = Mode.valueOf(mode);
if (op == null) {
LOGGER.error("Undefined mode " + mode);
return null;
}
}
if (pairs == null || pairs.length == 0) {
LOGGER.error("keys and values must be specified for the MapRewritePolicy");
return null;
}
final Map<String, String> map = new HashMap<String, String>();
for (final KeyValuePair pair : pairs) {
final String key = pair.getKey();
if (key == null) {
LOGGER.error("A null key is not valid in MapRewritePolicy");
continue;
}
final String value = pair.getValue();
if (value == null) {
LOGGER.error("A null value for key " + key + " is not allowed in MapRewritePolicy");
continue;
}
map.put(pair.getKey(), pair.getValue());
}
if (map.isEmpty()) {
LOGGER.error("MapRewritePolicy is not configured with any valid key value pairs");
return null;
}
return new MapRewritePolicy(map, op);
}
}