001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.log4j.rewrite;
018
019import org.apache.log4j.spi.LoggingEvent;
020
021/**
022 * This interface is implemented to provide a rewrite
023 * strategy for RewriteAppender.  RewriteAppender will
024 * call the rewrite method with a source logging event.
025 * The strategy may return that event, create a new event
026 * or return null to suppress the logging request.
027 */
028public interface RewritePolicy {
029    /**
030     * Rewrite a logging event.
031     * @param source a logging event that may be returned or
032     * used to create a new logging event.
033     * @return a logging event or null to suppress processing.
034     */
035    LoggingEvent rewrite(final LoggingEvent source);
036}