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.core.appender.rewrite;
018
019import java.util.Arrays;
020import java.util.HashMap;
021import java.util.List;
022import java.util.Map;
023
024import org.apache.logging.log4j.Logger;
025import org.apache.logging.log4j.core.Core;
026import org.apache.logging.log4j.core.LogEvent;
027import org.apache.logging.log4j.core.config.Configuration;
028import org.apache.logging.log4j.core.config.Property;
029import org.apache.logging.log4j.core.config.plugins.Plugin;
030import org.apache.logging.log4j.core.config.plugins.PluginConfiguration;
031import org.apache.logging.log4j.core.config.plugins.PluginElement;
032import org.apache.logging.log4j.core.config.plugins.PluginFactory;
033import org.apache.logging.log4j.core.impl.ContextDataFactory;
034import org.apache.logging.log4j.core.impl.Log4jLogEvent;
035import org.apache.logging.log4j.status.StatusLogger;
036import org.apache.logging.log4j.util.StringMap;
037
038/**
039 * This policy modifies events by replacing or possibly adding keys and values to the MapMessage.
040 */
041@Plugin(name = "PropertiesRewritePolicy", category = Core.CATEGORY_NAME, elementType = "rewritePolicy", printObject = true)
042public final class PropertiesRewritePolicy implements RewritePolicy {
043
044    /**
045     * Allows subclasses access to the status logger without creating another instance.
046     */
047    protected static final Logger LOGGER = StatusLogger.getLogger();
048
049    private final Map<Property, Boolean> properties;
050
051    private final Configuration config;
052
053    private PropertiesRewritePolicy(final Configuration config, final List<Property> props) {
054        this.config = config;
055        this.properties = new HashMap<>(props.size());
056        for (final Property property : props) {
057            final Boolean interpolate = Boolean.valueOf(property.getValue().contains("${"));
058            properties.put(property, interpolate);
059        }
060    }
061
062    /**
063     * Rewrites the event.
064     * @param source a logging event that may be returned or
065     * used to create a new logging event.
066     * @return The LogEvent after rewriting.
067     */
068    @Override
069    public LogEvent rewrite(final LogEvent source) {
070        final StringMap newContextData = ContextDataFactory.createContextData(source.getContextData());
071        for (final Map.Entry<Property, Boolean> entry : properties.entrySet()) {
072            final Property prop = entry.getKey();
073            newContextData.putValue(prop.getName(), entry.getValue().booleanValue() ?
074                config.getStrSubstitutor().replace(prop.getValue()) : prop.getValue());
075        }
076
077        return new Log4jLogEvent.Builder(source).setContextData(newContextData).build();
078    }
079
080    @Override
081    public String toString() {
082        final StringBuilder sb = new StringBuilder();
083        sb.append(" {");
084        boolean first = true;
085        for (final Map.Entry<Property, Boolean> entry : properties.entrySet()) {
086            if (!first) {
087                sb.append(", ");
088            }
089            final Property prop = entry.getKey();
090            sb.append(prop.getName()).append('=').append(prop.getValue());
091            first = false;
092        }
093        sb.append('}');
094        return sb.toString();
095    }
096
097    /**
098     * Creates a PropertiesRewritePolicy.
099     * @param config The Configuration.
100     * @param props key/value pairs for the new keys and values.
101     * @return The PropertiesRewritePolicy.
102     */
103    @PluginFactory
104    public static PropertiesRewritePolicy createPolicy(@PluginConfiguration final Configuration config,
105                                                @PluginElement("Properties") final Property[] props) {
106        if (props == null || props.length == 0) {
107            LOGGER.error("Properties must be specified for the PropertiesRewritePolicy");
108            return null;
109        }
110        final List<Property> properties = Arrays.asList(props);
111        return new PropertiesRewritePolicy(config, properties);
112    }
113}