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.pattern;
018
019import org.apache.logging.log4j.core.LogEvent;
020import org.apache.logging.log4j.core.config.Configuration;
021import org.apache.logging.log4j.core.config.plugins.Plugin;
022import org.apache.logging.log4j.message.Message;
023import 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" })
030public 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(result);
072            } else {
073                toAppendTo.append("null");
074            }
075        }
076    }
077}