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