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 */
017package org.apache.log4j.spi;
018
019import java.util.Enumeration;
020
021import org.apache.log4j.Appender;
022import org.apache.log4j.Category;
023import org.apache.log4j.Level;
024import org.apache.log4j.Logger;
025
026/**
027 * A <code>LoggerRepository</code> is used to create and retrieve <code>Loggers</code>.
028 * <p>
029 * The relation between loggers in a repository depends on the repository but typically loggers are arranged in a named
030 * hierarchy.
031 * </p>
032 * <p>
033 * In addition to the creational methods, a <code>LoggerRepository</code> can be queried for existing loggers, can act
034 * as a point of registry for events related to loggers.
035 * </p>
036 *
037 * @since 1.2
038 */
039public interface LoggerRepository {
040
041    /**
042     * Add a {@link HierarchyEventListener} event to the repository.
043     *
044     * @param listener The listener
045     */
046    void addHierarchyEventListener(HierarchyEventListener listener);
047
048    /**
049     * Returns whether this repository is disabled for a given
050     * level. The answer depends on the repository threshold and the
051     * <code>level</code> parameter. See also {@link #setThreshold}
052     * method.
053     *
054     * @param level The level
055     * @return whether this repository is disabled.
056     */
057    boolean isDisabled(int level);
058
059    /**
060     * Set the repository-wide threshold. All logging requests below the
061     * threshold are immediately dropped. By default, the threshold is
062     * set to <code>Level.ALL</code> which has the lowest possible rank.
063     *
064     * @param level The level
065     */
066    void setThreshold(Level level);
067
068    /**
069     * Another form of {@link #setThreshold(Level)} accepting a string
070     * parameter instead of a <code>Level</code>.
071     *
072     * @param val The threshold value
073     */
074    void setThreshold(String val);
075
076    void emitNoAppenderWarning(Category cat);
077
078    /**
079     * Get the repository-wide threshold. See {@link #setThreshold(Level)} for an explanation.
080     *
081     * @return the level.
082     */
083    Level getThreshold();
084
085    Logger getLogger(String name);
086
087    Logger getLogger(String name, LoggerFactory factory);
088
089    Logger getRootLogger();
090
091    Logger exists(String name);
092
093    void shutdown();
094
095    @SuppressWarnings("rawtypes")
096    Enumeration getCurrentLoggers();
097
098    /**
099     * Deprecated. Please use {@link #getCurrentLoggers} instead.
100     *
101     * @return an enumeration of loggers.
102     */
103    @SuppressWarnings("rawtypes")
104    Enumeration getCurrentCategories();
105
106    void fireAddAppenderEvent(Category logger, Appender appender);
107
108    void resetConfiguration();
109}