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.spi;
018    
019    import org.apache.logging.log4j.message.MessageFactory;
020    
021    /**
022     * Anchor point for logging implementations.
023     */
024    public interface LoggerContext {
025    
026        /**
027         * An anchor for some other context, such as a ClassLoader or ServletContext.
028         * @return The external context.
029         */
030        Object getExternalContext();
031    
032        /**
033         * Returns a Logger.
034         * @param name The name of the Logger to return.
035         * @return The logger with the specified name.
036         */
037        ExtendedLogger getLogger(String name);
038    
039        /**
040         * Returns a Logger.
041         * @param name The name of the Logger to return.
042         * @param messageFactory The message factory is used only when creating a logger, subsequent use does not change
043         *                       the logger but will log a warning if mismatched.
044         * @return The logger with the specified name.
045         */
046        ExtendedLogger getLogger(String name, MessageFactory messageFactory);
047    
048        /**
049         * Detects if a Logger with the specified name exists.
050         * @param name The Logger name to search for.
051         * @return true if the Logger exists, false otherwise.
052         */
053        boolean hasLogger(String name);
054    }