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.pattern;
018    
019    import org.apache.logging.log4j.core.LogEvent;
020    import org.apache.logging.log4j.core.config.Configuration;
021    import org.apache.logging.log4j.core.config.plugins.Plugin;
022    import org.apache.logging.log4j.message.Message;
023    import org.apache.logging.log4j.message.MultiformatMessage;
024    
025    /**
026     * Returns the event's rendered message in a StringBuilder.
027     */
028    @Plugin(name = "MessagePatternConverter", category = PatternConverter.CATEGORY)
029    @ConverterKeys({ "m", "msg", "message" })
030    public final class MessagePatternConverter extends LogEventPatternConverter {
031    
032        private final String[] formats;
033    
034        private final Configuration config;
035    
036        /**
037         * Private constructor.
038         * @param options options, may be null.
039         */
040        private MessagePatternConverter(final Configuration config, final String[] options) {
041            super("Message", "message");
042            formats = options;
043            this.config = config;
044        }
045    
046        /**
047         * Obtains an instance of pattern converter.
048         *
049         * @param config The Configuration.
050         * @param options options, may be null.
051         * @return instance of pattern converter.
052         */
053        public static MessagePatternConverter newInstance(final Configuration config, final String[] options) {
054            return new MessagePatternConverter(config, options);
055        }
056    
057        /**
058         * {@inheritDoc}
059         */
060        @Override
061        public void format(final LogEvent event, final StringBuilder toAppendTo) {
062            final Message msg = event.getMessage();
063            if (msg != null) {
064                String result;
065                if (msg instanceof MultiformatMessage) {
066                    result = ((MultiformatMessage) msg).getFormattedMessage(formats);
067                } else {
068                    result = msg.getFormattedMessage();
069                }
070                if (result != null) {
071                    toAppendTo.append(config != null && result.contains("${") ?
072                        config.getStrSubstitutor().replace(event, result) : result);
073                } else {
074                    toAppendTo.append("null");
075                }
076            }
077        }
078    }