/* * Copyright 1999-2005 The Apache Software Foundation. * * Licensed 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 org.apache.log4j; import org.apache.log4j.spi.OptionHandler; import org.apache.log4j.spi.LoggingEvent; /** Extend this abstract class to create your own log layout format. @author Ceki Gülcü */ public abstract class Layout implements OptionHandler { // Note that the line.separator property can be looked up even by // applets. public final static String LINE_SEP = System.getProperty("line.separator"); public final static int LINE_SEP_LEN = LINE_SEP.length(); /** Implement this method to create your own layout format. */ abstract public String format(LoggingEvent event); /** Returns the content type output by this layout. The base class returns "text/plain". */ public String getContentType() { return "text/plain"; } /** Returns the header for the layout format. The base class returns <code>null</code>. */ public String getHeader() { return null; } /** Returns the footer for the layout format. The base class returns <code>null</code>. */ public String getFooter() { return null; } /** If the layout handles the throwable object contained within {@link LoggingEvent}, then the layout should return <code>false</code>. Otherwise, if the layout ignores throwable object, then the layout should return <code>true</code>. <p>The {@link SimpleLayout}, {@link TTCCLayout}, {@link PatternLayout} all return <code>true</code>. The {@link org.apache.log4j.xml.XMLLayout} returns <code>false</code>. @since 0.8.4 */ abstract public boolean ignoresThrowable(); }