/*  * Copyright 2004-2005 OpenSymphony  *  * Licensed 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. *  *//* * Previously Copyright (c) 2001-2004 James House */package org.quartz.impl;import java.util.Collection;import java.util.HashMap;import org.quartz.Scheduler;import org.quartz.SchedulerException;/** * <p> * Holds references to Scheduler instances - ensuring uniqueness, and * preventing garbage collection, and allowing 'global' lookups - all within a * ClassLoader space. * </p> *  * @author James House */public class SchedulerRepository {    /*     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~     *      * Data members.     *      * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~     */    private HashMap schedulers;    private static SchedulerRepository inst;    /*     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~     *      * Constructors.     *      * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~     */    private SchedulerRepository() {        schedulers = new HashMap();    }    /*     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~     *      * Interface.     *      * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~     */    public static synchronized SchedulerRepository getInstance() {        if (inst == null) {            inst = new SchedulerRepository();        }        return inst;    }    public synchronized void bind(Scheduler sched) throws SchedulerException {        if ((Scheduler) schedulers.get(sched.getSchedulerName()) != null) {            throw new SchedulerException("Scheduler with name '"                    + sched.getSchedulerName() + "' already exists.",                    SchedulerException.ERR_BAD_CONFIGURATION);        }        schedulers.put(sched.getSchedulerName(), sched);    }    public synchronized boolean remove(String schedName) {        return (schedulers.remove(schedName) != null);    }    public synchronized Scheduler lookup(String schedName) {        return (Scheduler) schedulers.get(schedName);    }    public synchronized Collection lookupAll() {        return java.util.Collections                .unmodifiableCollection(schedulers.values());    }}