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 package org.apache.logging.log4j.core.filter;
018
019 import org.apache.logging.log4j.Level;
020 import org.apache.logging.log4j.Marker;
021 import org.apache.logging.log4j.core.Filter;
022 import org.apache.logging.log4j.core.Lifecycle;
023 import org.apache.logging.log4j.core.LogEvent;
024 import org.apache.logging.log4j.core.Logger;
025 import org.apache.logging.log4j.status.StatusLogger;
026 import org.apache.logging.log4j.message.Message;
027
028 /**
029 * Users should extend this class to implement filters. Filters can be either context wide or attached to
030 * an appender. A filter may choose to support being called only from the context or only from an appender in
031 * which case it will only implement the required method(s). The rest will default to return NEUTRAL.
032 *
033 */
034 public abstract class FilterBase implements Filter, Lifecycle {
035 /**
036 * Allow subclasses access to the status logger without creating another instance.
037 */
038 protected static final org.apache.logging.log4j.Logger LOGGER = StatusLogger.getLogger();
039
040 /**
041 * The onMatch Result.
042 */
043 protected final Result onMatch;
044
045 /**
046 * The onMismatch Result.
047 */
048 protected final Result onMismatch;
049
050 private boolean started;
051
052 /**
053 * The default constructor.
054 */
055 protected FilterBase() {
056 this(null, null);
057 }
058
059 /**
060 * Constructor that allows the onMatch and onMismatch actions to be set.
061 * @param onMatch The result to return when a match occurs.
062 * @param onMismatch The result to return when a match dos not occur.
063 */
064 protected FilterBase(Result onMatch, Result onMismatch) {
065 this.onMatch = onMatch == null ? Result.NEUTRAL : onMatch;
066 this.onMismatch = onMismatch == null ? Result.DENY : onMismatch;
067 }
068
069 /**
070 * Mark the Filter as started.
071 */
072 public void start() {
073 started = true;
074 }
075
076 /**
077 * Determine if the the Filter has started.
078 * @return true if the Filter is started, false otherwise.
079 */
080 public boolean isStarted() {
081 return started;
082 }
083
084 /**
085 * Mark the Filter as stopped.
086 */
087 public void stop() {
088 started = false;
089 }
090
091 /**
092 * Return the Result to be returned when a match does not occur.
093 * @return the onMismatch Result.
094 */
095 public final Result getOnMismatch() {
096 return onMismatch;
097 }
098
099 /**
100 * Return the Result to be returned when a match occurs.
101 * @return the onMatch Result.
102 */
103 public final Result getOnMatch() {
104 return onMatch;
105 }
106
107 @Override
108 public String toString() {
109 return this.getClass().getSimpleName();
110 }
111
112 /**
113 * Appender Filter method. The default returns NEUTRAL.
114 * @param logger the Logger.
115 * @param level The logging Level.
116 * @param marker The Marker, if any.
117 * @param msg The message, if present.
118 * @param params An array of parameters or null.
119 * @return The Result of filtering.
120 */
121 public Result filter(Logger logger, Level level, Marker marker, String msg, Object[] params) {
122 return Result.NEUTRAL;
123 }
124
125 /**
126 * Appender Filter method. The default returns NEUTRAL.
127 * @param logger the Logger.
128 * @param level The logging Level.
129 * @param marker The Marker, if any.
130 * @param msg The message, if present.
131 * @param t A throwable or null.
132 * @return The Result of filtering.
133 */
134 public Result filter(Logger logger, Level level, Marker marker, Object msg, Throwable t) {
135 return Result.NEUTRAL;
136 }
137
138 /**
139 * Appender Filter method. The default returns NEUTRAL.
140 * @param logger the Logger.
141 * @param level The logging Level.
142 * @param marker The Marker, if any.
143 * @param msg The message, if present.
144 * @param t A throwable or null.
145 * @return The Result of filtering.
146 */
147 public Result filter(Logger logger, Level level, Marker marker, Message msg, Throwable t) {
148 return Result.NEUTRAL;
149 }
150
151 /**
152 * Context Filter method. The default returns NEUTRAL.
153 * @param event The LogEvent.
154 * @return The Result of filtering.
155 */
156 public Result filter(LogEvent event) {
157 return Result.NEUTRAL;
158 }
159 }