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 */ 017 018package org.apache.logging.log4j.core; 019 020import org.apache.logging.log4j.Level; 021import org.apache.logging.log4j.Marker; 022import org.apache.logging.log4j.message.Message; 023import org.apache.logging.log4j.util.EnglishEnums; 024 025/** 026 * Interface that must be implemented to allow custom event filtering. It is highly recommended that 027 * applications make use of the Filters provided with this implementation before creating their own. 028 * 029 * <p>This interface supports "global" filters (i.e. - all events must pass through them first), attached to 030 * specific loggers and associated with Appenders. It is recommended that, where possible, Filter implementations 031 * create a generic filtering method that can be called from any of the filter methods.</p> 032 */ 033public interface Filter extends LifeCycle { 034 035 /** 036 * Main {@linkplain org.apache.logging.log4j.core.config.plugins.Plugin#elementType() plugin element type} for 037 * Filter plugins. 038 * 039 * @since 2.1 040 */ 041 String ELEMENT_TYPE = "filter"; 042 043 /** 044 * The result that can returned from a filter method call. 045 */ 046 enum Result { 047 /** 048 * The event will be processed without further filtering based on the log Level. 049 */ 050 ACCEPT, 051 /** 052 * No decision could be made, further filtering should occur. 053 */ 054 NEUTRAL, 055 /** 056 * The event should not be processed. 057 */ 058 DENY; 059 060 /** 061 * Returns the Result for the given string. 062 * 063 * @param name The Result enum name, case-insensitive. If null, returns, null 064 * @return a Result enum value or null if name is null 065 */ 066 public static Result toResult(final String name) { 067 return toResult(name, null); 068 } 069 070 /** 071 * Returns the Result for the given string. 072 * 073 * @param name The Result enum name, case-insensitive. If null, returns, defaultResult 074 * @param defaultResult the Result to return if name is null 075 * @return a Result enum value or null if name is null 076 */ 077 public static Result toResult(final String name, final Result defaultResult) { 078 return EnglishEnums.valueOf(Result.class, name, defaultResult); 079 } 080} 081 082 /** 083 * Returns the result that should be returned when the filter does not match the event. 084 * @return the Result that should be returned when the filter does not match the event. 085 */ 086 Result getOnMismatch(); 087 /** 088 * Returns the result that should be returned when the filter matches the event. 089 * @return the Result that should be returned when the filter matches the event. 090 */ 091 Result getOnMatch(); 092 093 /** 094 * Filter an event. 095 * @param logger The Logger. 096 * @param level The event logging Level. 097 * @param marker The Marker for the event or null. 098 * @param msg String text to filter on. 099 * @param params An array of parameters or null. 100 * @return the Result. 101 */ 102 Result filter(Logger logger, Level level, Marker marker, String msg, Object... params); 103 104 /** 105 * Filter an event. 106 * @param logger The Logger. 107 * @param level The event logging Level. 108 * @param marker The Marker for the event or null. 109 * @param msg Any Object. 110 * @param t A Throwable or null. 111 * @return the Result. 112 */ 113 Result filter(Logger logger, Level level, Marker marker, Object msg, Throwable t); 114 115 /** 116 * Filter an event. 117 * @param logger The Logger. 118 * @param level The event logging Level. 119 * @param marker The Marker for the event or null. 120 * @param msg The Message 121 * @param t A Throwable or null. 122 * @return the Result. 123 */ 124 Result filter(Logger logger, Level level, Marker marker, Message msg, Throwable t); 125 126 /** 127 * Filter an event. 128 * @param event The Event to filter on. 129 * @return the Result. 130 */ 131 Result filter(LogEvent event); 132 133}