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 static final long serialVersionUID = 1L;
033    
034        private final ThreadLocal<AppenderControl> recursive = new ThreadLocal<AppenderControl>();
035    
036        private final Appender appender;
037    
038        private final Level level;
039    
040        private final int intLevel;
041    
042        /**
043         * Constructor.
044         * @param appender The target Appender.
045         * @param level the Level to filter on.
046         * @param filter the Filter(s) to apply.
047         */
048        public AppenderControl(final Appender appender, final Level level, final Filter filter) {
049            super(filter);
050            this.appender = appender;
051            this.level = level;
052            this.intLevel = level == null ? Level.ALL.intLevel() : level.intLevel();
053            start();
054        }
055    
056        /**
057         * Returns the Appender.
058         * @return the Appender.
059         */
060        public Appender getAppender() {
061            return appender;
062        }
063    
064        /**
065         * Call the appender.
066         * @param event The event to process.
067         */
068        public void callAppender(final LogEvent event) {
069            if (getFilter() != null) {
070                final Filter.Result r = getFilter().filter(event);
071                if (r == Filter.Result.DENY) {
072                    return;
073                }
074            }
075            if (level != null && intLevel < event.getLevel().intLevel()) {
076                return;
077            }
078            if (recursive.get() != null) {
079                appender.getHandler().error("Recursive call to appender " + appender.getName());
080                return;
081            }
082            try {
083                recursive.set(this);
084    
085                if (!appender.isStarted()) {
086                    appender.getHandler().error("Attempted to append to non-started appender " + appender.getName());
087    
088                    if (!appender.ignoreExceptions()) {
089                        throw new AppenderLoggingException(
090                            "Attempted to append to non-started appender " + appender.getName());
091                    }
092                }
093    
094                if (appender instanceof Filterable && ((Filterable) appender).isFiltered(event)) {
095                    return;
096                }
097    
098                try {
099                    appender.append(event);
100                } catch (final RuntimeException ex) {
101                    appender.getHandler().error("An exception occurred processing Appender " + appender.getName(), ex);
102                    if (!appender.ignoreExceptions()) {
103                        throw ex;
104                    }
105                } catch (final Exception ex) {
106                    appender.getHandler().error("An exception occurred processing Appender " + appender.getName(), ex);
107                    if (!appender.ignoreExceptions()) {
108                        throw new AppenderLoggingException(ex);
109                    }
110                }
111            } finally {
112                recursive.set(null);
113            }
114        }
115    
116    }