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