/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package examples; import org.apache.log4j.*; import org.apache.log4j.helpers.PatternParser; /** Example showing how to extend PatternLayout to recognize additional conversion characters. <p>In this case MyPatternLayout recognizes %# conversion pattern. It outputs the value of an internal counter which is also incremented at each call. <p>See <a href=doc-files/MyPatternLayout.java><b>source</b></a> code for more details. @see MyPatternParser @see org.apache.log4j.PatternLayout @author Anders Kristensen */ public class MyPatternLayout extends PatternLayout { public MyPatternLayout() { this(DEFAULT_CONVERSION_PATTERN); } public MyPatternLayout(String pattern) { super(pattern); } public PatternParser createPatternParser(String pattern) { return new MyPatternParser( pattern == null ? DEFAULT_CONVERSION_PATTERN : pattern); } public static void main(String[] args) { Layout layout = new MyPatternLayout("[counter=%.10#] - %m%n"); Logger logger = Logger.getLogger("some.cat"); logger.addAppender(new ConsoleAppender(layout, ConsoleAppender.SYSTEM_OUT)); logger.debug("Hello, log"); logger.info("Hello again..."); } }