001/**
002 * Logback: the reliable, generic, fast and flexible logging framework.
003 * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
004 *
005 * This program and the accompanying materials are dual-licensed under
006 * either the terms of the Eclipse Public License v1.0 as published by
007 * the Eclipse Foundation
008 *
009 *   or (per the licensee's choosing)
010 *
011 * under the terms of the GNU Lesser General Public License version 2.1
012 * as published by the Free Software Foundation.
013 */
014package ch.qos.logback.classic.pattern;
015
016import java.util.Map;
017
018import ch.qos.logback.classic.spi.ILoggingEvent;
019import ch.qos.logback.classic.spi.LoggerContextVO;
020
021public final class PropertyConverter extends ClassicConverter {
022
023    String key;
024
025    public void start() {
026        String optStr = getFirstOption();
027        if (optStr != null) {
028            key = optStr;
029            super.start();
030        }
031    }
032
033    public String convert(ILoggingEvent event) {
034        if (key == null) {
035            return "Property_HAS_NO_KEY";
036        } else {
037            LoggerContextVO lcvo = event.getLoggerContextVO();
038            Map<String, String> map = lcvo.getPropertyMap();
039            String val = map.get(key);
040            if (val != null) {
041                return val;
042            } else {
043                return System.getProperty(key);
044            }
045        }
046    }
047}