/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements.  See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License.  You may obtain a copy of the License at * *      http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */package org.apache.log4j.spi;import org.apache.log4j.Level;import org.apache.log4j.Category;import org.apache.log4j.Logger;import org.apache.log4j.Appender;import java.util.Enumeration;import java.util.Vector;/** *  No-operation implementation of LoggerRepository which is used when *  LogManager.repositorySelector is erroneously nulled during class reloading. *  @since 1.2.15 */public final class NOPLoggerRepository implements LoggerRepository {    /**     * {@inheritDoc}    */    public void addHierarchyEventListener(final HierarchyEventListener listener) {    }    /**     * {@inheritDoc}     */    public boolean isDisabled(final int level) {        return true;    }    /**     * {@inheritDoc}     */    public void setThreshold(final Level level) {    }    /**     * {@inheritDoc}     */    public void setThreshold(final String val) {    }    /**     * {@inheritDoc}     */    public void emitNoAppenderWarning(final Category cat) {    }    /**     * {@inheritDoc}     */    public Level getThreshold() {        return Level.OFF;    }    /**     * {@inheritDoc}     */    public Logger getLogger(final String name) {        return new NOPLogger(this, name);    }    /**     * {@inheritDoc}     */    public Logger getLogger(final String name, final LoggerFactory factory) {        return new NOPLogger(this, name);    }    /**     * {@inheritDoc}     */    public Logger getRootLogger() {        return new NOPLogger(this, "root");    }    /**     * {@inheritDoc}     */    public Logger exists(final String name) {        return null;    }    /**     * {@inheritDoc}     */    public void shutdown() {    }    /**     * {@inheritDoc}     */    public Enumeration getCurrentLoggers() {        return new Vector().elements();    }    /**     * {@inheritDoc}     */    public Enumeration getCurrentCategories() {        return getCurrentLoggers();    }    /**     * {@inheritDoc}     */    public  void fireAddAppenderEvent(Category logger, Appender appender) {    }    /**     * {@inheritDoc}     */    public void resetConfiguration() {    }}