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.config;
018    
019    import org.apache.logging.log4j.Level;
020    import org.apache.logging.log4j.core.Appender;
021    import org.apache.logging.log4j.core.Filter;
022    import org.apache.logging.log4j.core.LogEvent;
023    import org.apache.logging.log4j.core.appender.AppenderLoggingException;
024    import org.apache.logging.log4j.core.filter.AbstractFilterable;
025    import org.apache.logging.log4j.core.filter.Filterable;
026    
027    /**
028     * Wraps an {@link Appender} with details an appender implementation shouldn't need to know about.
029     */
030    public class AppenderControl extends AbstractFilterable {
031    
032        private final ThreadLocal<AppenderControl> recursive = new ThreadLocal<AppenderControl>();
033    
034        private final Appender appender;
035    
036        private final Level level;
037    
038        private final int intLevel;
039    
040        /**
041         * Constructor.
042         * @param appender The target Appender.
043         * @param level the Level to filter on.
044         * @param filter the Filter(s) to apply.
045         */
046        public AppenderControl(final Appender appender, final Level level, final Filter filter) {
047            super(filter);
048            this.appender = appender;
049            this.level = level;
050            this.intLevel = level == null ? Level.ALL.intLevel() : level.intLevel();
051            start();
052        }
053    
054        /**
055         * Returns the Appender.
056         * @return the Appender.
057         */
058        public Appender getAppender() {
059            return appender;
060        }
061    
062        /**
063         * Call the appender.
064         * @param event The event to process.
065         */
066        public void callAppender(final LogEvent event) {
067            if (getFilter() != null) {
068                final Filter.Result r = getFilter().filter(event);
069                if (r == Filter.Result.DENY) {
070                    return;
071                }
072            }
073            if (level != null && intLevel < event.getLevel().intLevel()) {
074                return;
075            }
076            if (recursive.get() != null) {
077                appender.getHandler().error("Recursive call to appender " + appender.getName());
078                return;
079            }
080            try {
081                recursive.set(this);
082    
083                if (!appender.isStarted()) {
084                    appender.getHandler().error("Attempted to append to non-started appender " + appender.getName());
085    
086                    if (!appender.ignoreExceptions()) {
087                        throw new AppenderLoggingException(
088                            "Attempted to append to non-started appender " + appender.getName());
089                    }
090                }
091    
092                if (appender instanceof Filterable && ((Filterable) appender).isFiltered(event)) {
093                    return;
094                }
095    
096                try {
097                    appender.append(event);
098                } catch (final RuntimeException ex) {
099                    appender.getHandler().error("An exception occurred processing Appender " + appender.getName(), ex);
100                    if (!appender.ignoreExceptions()) {
101                        throw ex;
102                    }
103                } catch (final Exception ex) {
104                    appender.getHandler().error("An exception occurred processing Appender " + appender.getName(), ex);
105                    if (!appender.ignoreExceptions()) {
106                        throw new AppenderLoggingException(ex);
107                    }
108                }
109            } finally {
110                recursive.set(null);
111            }
112        }
113    
114    }