    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    }