1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 package org.apache.log4j.varia; 19 20 import org.apache.log4j.AppenderSkeleton; 21 import org.apache.log4j.spi.LoggingEvent; 22 23 /** 24 * A NullAppender merely exists, it never outputs a message to any 25 * device. 26 * @author Ceki Gülc¨ 27 */ 28 public class NullAppender extends AppenderSkeleton { 29 30 private static NullAppender instance = new NullAppender(); 31 32 public NullAppender() { 33 } 34 35 /** 36 * There are no options to acticate. 37 * */ 38 public void activateOptions() { 39 } 40 41 /** 42 * Whenever you can, use this method to retreive an instance instead 43 * of instantiating a new one with <code>new</code>. 44 * @deprecated Use getNullAppender instead. getInstance should have been static. 45 * */ 46 public NullAppender getInstance() { 47 return instance; 48 } 49 50 /** 51 * Whenever you can, use this method to retreive an instance instead 52 * of instantiating a new one with <code>new</code>. 53 * */ 54 public static NullAppender getNullAppender() { 55 return instance; 56 } 57 58 public void close() { 59 } 60 61 /** 62 * Does not do anything. 63 * */ 64 public void doAppend(LoggingEvent event) { 65 } 66 67 /** 68 * Does not do anything. 69 * */ 70 protected void append(LoggingEvent event) { 71 } 72 73 /** 74 * NullAppenders do not need a layout. 75 * */ 76 public boolean requiresLayout() { 77 return false; 78 } 79 }