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.core.Filter;
020    import org.apache.logging.log4j.core.LifeCycle;
021    import org.apache.logging.log4j.core.LogEvent;
022    
023    /**
024     * Interface implemented by Classes that allow filtering to occur.
025     * 
026     * <p>
027     * Extends {@link LifeCycle} since filters have a life cycle.
028     * </p>
029     */
030    public interface Filterable extends LifeCycle {
031    
032        /**
033         * Adds a new Filter. If a Filter already exists it is converted to a CompositeFilter.
034         * @param filter The Filter to add.
035         */
036        void addFilter(Filter filter);
037    
038        /**
039         * Removes a Filter.
040         * @param filter The Filter to remove.
041         */
042        void removeFilter(Filter filter);
043    
044        /**
045         * Returns an Iterator for all the Filters.
046         * @return an Iterator for all the Filters.
047         */
048        Filter getFilter();
049    
050        /**
051         * Determine if a Filter is present.
052         * @return true if a Filter is present, false otherwise.
053         */
054        boolean hasFilter();
055    
056        /**
057         * Determines if the event should be filtered.
058         * @param event The LogEvent.
059         * @return true if the event should be filtered, false otherwise.
060         */
061        boolean isFiltered(LogEvent event);
062    }