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.AbstractLifeCycle;
022    import org.apache.logging.log4j.core.Filter;
023    import org.apache.logging.log4j.core.LogEvent;
024    import org.apache.logging.log4j.core.Logger;
025    import org.apache.logging.log4j.message.Message;
026    
027    /**
028     * Users should extend this class to implement filters. Filters can be either context wide or attached to
029     * an appender. A filter may choose to support being called only from the context or only from an appender in
030     * which case it will only implement the required method(s). The rest will default to return NEUTRAL.
031     *
032     */
033    public abstract class AbstractFilter extends AbstractLifeCycle implements Filter {
034        
035        /**
036         * The onMatch Result.
037         */
038        protected final Result onMatch;
039    
040        /**
041         * The onMismatch Result.
042         */
043        protected final Result onMismatch;
044    
045        /**
046         * The default constructor.
047         */
048        protected AbstractFilter() {
049            this(null, null);
050        }
051    
052        /**
053         * Constructor that allows the onMatch and onMismatch actions to be set.
054         * @param onMatch The result to return when a match occurs.
055         * @param onMismatch The result to return when a match dos not occur.
056         */
057        protected AbstractFilter(final Result onMatch, final Result onMismatch) {
058            this.onMatch = onMatch == null ? Result.NEUTRAL : onMatch;
059            this.onMismatch = onMismatch == null ? Result.DENY : onMismatch;
060        }
061    
062        /**
063         * Returns the Result to be returned when a match does not occur.
064         * @return the onMismatch Result.
065         */
066        @Override
067        public final Result getOnMismatch() {
068            return onMismatch;
069        }
070    
071        /**
072         * Returns the Result to be returned when a match occurs.
073         * @return the onMatch Result.
074         */
075        @Override
076        public final Result getOnMatch() {
077            return onMatch;
078        }
079    
080        @Override
081        public String toString() {
082            return this.getClass().getSimpleName();
083        }
084    
085        /**
086         * Appender Filter method. The default returns NEUTRAL.
087         * @param logger the Logger.
088         * @param level The logging Level.
089         * @param marker The Marker, if any.
090         * @param msg The message, if present.
091         * @param params An array of parameters or null.
092         * @return The Result of filtering.
093         */
094        @Override
095        public Result filter(final Logger logger, final Level level, final Marker marker, final String msg,
096                             final Object... params) {
097            return Result.NEUTRAL;
098        }
099    
100        /**
101         * Appender Filter method. The default returns NEUTRAL.
102         * @param logger the Logger.
103         * @param level The logging Level.
104         * @param marker The Marker, if any.
105         * @param msg The message, if present.
106         * @param t A throwable or null.
107         * @return The Result of filtering.
108         */
109        @Override
110        public Result filter(final Logger logger, final Level level, final Marker marker, final Object msg,
111                             final Throwable t) {
112            return Result.NEUTRAL;
113        }
114    
115        /**
116         * Appender Filter method. The default returns NEUTRAL.
117         * @param logger the Logger.
118         * @param level The logging Level.
119         * @param marker The Marker, if any.
120         * @param msg The message, if present.
121         * @param t A throwable or null.
122         * @return The Result of filtering.
123         */
124        @Override
125        public Result filter(final Logger logger, final Level level, final Marker marker, final Message msg,
126                             final Throwable t) {
127            return Result.NEUTRAL;
128        }
129    
130        /**
131         * Context Filter method. The default returns NEUTRAL.
132         * @param event The LogEvent.
133         * @return The Result of filtering.
134         */
135        @Override
136        public Result filter(final LogEvent event) {
137            return Result.NEUTRAL;
138        }
139    }