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.plugins.Plugin;
021import org.apache.logging.log4j.util.ProcessIdUtil;
022
023@Plugin(name = "ProcessIdPatternConverter", category = "Converter")
024@ConverterKeys({ "pid", "processId" })
025public final class ProcessIdPatternConverter extends LogEventPatternConverter {
026    private static final String DEFAULT_DEFAULT_VALUE = "???";
027    private final String pid;
028
029    /**
030     * Private constructor.
031     */
032    private ProcessIdPatternConverter(final String... options) {
033        super("Process ID", "pid");
034        final String defaultValue = options.length > 0 ? options[0] : DEFAULT_DEFAULT_VALUE;
035        final String discoveredPid = ProcessIdUtil.getProcessId();
036        pid = discoveredPid.equals(ProcessIdUtil.DEFAULT_PROCESSID) ? defaultValue : discoveredPid;
037    }
038
039    /**
040     * Returns the process ID.
041     * @return the process ID
042     */
043    public String getProcessId() {
044        return pid;
045    }
046
047    public static void main(final String[] args) {
048        System.out.println(new ProcessIdPatternConverter().pid);
049    }
050
051    /**
052     * Obtains an instance of ProcessIdPatternConverter.
053     *
054     * @param options options, currently ignored, may be null.
055     * @return instance of ProcessIdPatternConverter.
056     */
057    public static ProcessIdPatternConverter newInstance(final String[] options) {
058        return new ProcessIdPatternConverter(options);
059    }
060
061    /**
062     * {@inheritDoc}
063     */
064    @Override
065    public void format(final LogEvent event, final StringBuilder toAppendTo) {
066        toAppendTo.append(pid);
067    }
068}