/* * 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.Filter; import org.apache.log4j.spi.ErrorHandler; import org.apache.log4j.spi.LoggingEvent; /** Implement this interface for your own strategies for outputting log statements. @author Ceki Gülcü */ public interface Appender { /** Add a filter to the end of the filter list. @since 0.9.0 */ void addFilter(Filter newFilter); /** Returns the head Filter. The Filters are organized in a linked list and so all Filters on this Appender are available through the result. @return the head Filter or null, if no Filters are present @since 1.1 */ public Filter getFilter(); /** Clear the list of filters by removing all the filters in it. @since 0.9.0 */ public void clearFilters(); /** Release any resources allocated within the appender such as file handles, network connections, etc. <p>It is a programming error to append to a closed appender. @since 0.8.4 */ public void close(); /** Log in <code>Appender</code> specific way. When appropriate, Loggers will call the <code>doAppend</code> method of appender implementations in order to log. */ public void doAppend(LoggingEvent event); /** Get the name of this appender. The name uniquely identifies the appender. */ public String getName(); /** Set the {@link ErrorHandler} for this appender. @since 0.9.0 */ public void setErrorHandler(ErrorHandler errorHandler); /** Returns the {@link ErrorHandler} for this appender. @since 1.1 */ public ErrorHandler getErrorHandler(); /** Set the {@link Layout} for this appender. @since 0.8.1 */ public void setLayout(Layout layout); /** Returns this appenders layout. @since 1.1 */ public Layout getLayout(); /** Set the name of this appender. The name is used by other components to identify this appender. @since 0.8.1 */ public void setName(String name); /** Configurators call this method to determine if the appender requires a layout. If this method returns <code>true</code>, meaning that layout is required, then the configurator will configure an layout using the configuration information at its disposal. If this method returns <code>false</code>, meaning that a layout is not required, then layout configuration will be skipped even if there is available layout configuration information at the disposal of the configurator.. <p>In the rather exceptional case, where the appender implementation admits a layout but can also work without it, then the appender should return <code>true</code>. @since 0.8.4 */ public boolean requiresLayout(); }