    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.rewrite;
    018
    019    import java.util.Arrays;
    020    import java.util.HashMap;
    021    import java.util.List;
    022    import java.util.Map;
    023
    024    import org.apache.logging.log4j.Logger;
    025    import org.apache.logging.log4j.core.LogEvent;
    026    import org.apache.logging.log4j.core.config.Configuration;
    027    import org.apache.logging.log4j.core.config.Property;
    028    import org.apache.logging.log4j.core.config.plugins.Plugin;
    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    import org.apache.logging.log4j.core.impl.Log4jLogEvent;
    033    import org.apache.logging.log4j.status.StatusLogger;
    034
    035    /**
    036     * This policy modifies events by replacing or possibly adding keys and values to the MapMessage.
    037     */
    038    @Plugin(name = "PropertiesRewritePolicy", category = "Core", elementType = "rewritePolicy", printObject = true)
    039    public final class PropertiesRewritePolicy implements RewritePolicy {
    040        /**
    041         * Allow subclasses access to the status logger without creating another instance.
    042         */
    043        protected static final Logger LOGGER = StatusLogger.getLogger();
    044
    045        private final Map<Property, Boolean> properties;
    046
    047        private final Configuration config;
    048
    049        private PropertiesRewritePolicy(final Configuration config, final List<Property> props) {
    050            this.config = config;
    051            this.properties = new HashMap<Property, Boolean>(props.size());
    052            for (final Property property : props) {
    053                final Boolean interpolate = Boolean.valueOf(property.getValue().contains("${"));
    054                properties.put(property, interpolate);
    055            }
    056        }
    057
    058        /**
    059         * Rewrite the event.
    060         * @param source a logging event that may be returned or
    061         * used to create a new logging event.
    062         * @return The LogEvent after rewriting.
    063         */
    064        @Override
    065        public LogEvent rewrite(final LogEvent source) {
    066            final Map<String, String> props = new HashMap<String, String>(source.getContextMap());
    067            for (final Map.Entry<Property, Boolean> entry : properties.entrySet()) {
    068                final Property prop = entry.getKey();
    069                props.put(prop.getName(), entry.getValue().booleanValue() ?
    070                    config.getStrSubstitutor().replace(prop.getValue()) : prop.getValue());
    071            }
    072
    073            return new Log4jLogEvent(source.getLoggerName(), source.getMarker(), source.getLoggerFqcn(), source.getLevel(),
    074                source.getMessage(), source.getThrown(), props, source.getContextStack(), source.getThreadName(),
    075                source.getSource(), source.getTimeMillis());
    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    }