/* * Copyright 2001-2004 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.Layout; 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. *

*

It is a programming error to append to a closed appender. * * @since 0.8.4 */ public void close(); /** * Log in Appender specific way. When appropriate, * Loggers will call the doAppend 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 true, * meaning that layout is required, then the configurator will * configure an layout using the configuration information at its * disposal. If this method returns false, 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.. *

*

In the rather exceptional case, where the appender * implementation admits a layout but can also work without it, then * the appender should return true. * * @since 0.8.4 */ public boolean requiresLayout(); }