org.quartz.spi.SchedulerPlugin Maven / Gradle / Ivy

/* 
 * Copyright 2001-2009 Terracotta, Inc. 
 * 
 * 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.
 * 
 */

package org.quartz.spi;

import org.quartz.Scheduler;
import org.quartz.SchedulerException;

/**
 * 
 * Provides an interface for a class to become a "plugin" to Quartz.
 * 
 * 
 * 
 * Plugins can do virtually anything you wish, though the most interesting ones
 * will obviously interact with the scheduler in some way - either actively: by
 * invoking actions on the scheduler, or passively: by being a JobListener,
 * TriggerListener, and/or SchedulerListener.
 * 
 * 
 * 
 * If you use {@link org.quartz.impl.StdSchedulerFactory} to
 * initialize your Scheduler, it can also create and initialize your plugins -
 * look at the configuration docs for details.
 * 
 * 
 * 
 * If you need direct access your plugin, you can have it explicitly put a 
 * reference to itself in the Scheduler's 
 * SchedulerContext as part of its
 * {@link #initialize(String, Scheduler)} method.
 * 
 * 
 * @author James House
 */
public interface SchedulerPlugin {

    /*
     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     * 
     * Interface.
     * 
     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     */

    /**
     * 
     * Called during creation of the Scheduler in order to give
     * the SchedulerPlugin a chance to initialize.
     * 
     * 
     * 
     * At this point, the Scheduler's JobStore is not yet
     * initialized.
     * 
     * 
     * 
     * If you need direct access your plugin, for example during Job
     * execution, you can have this method explicitly put a 
     * reference to this plugin in the Scheduler's 
     * SchedulerContext.
     * 
     * 
     * @param name
     *          The name by which the plugin is identified.
     * @param scheduler
     *          The scheduler to which the plugin is registered.
     * 
     * @throws org.quartz.SchedulerConfigException
     *           if there is an error initializing.
     */
    void initialize(String name, Scheduler scheduler)
        throws SchedulerException;

    /**
     * 
     * Called when the associated Scheduler is started, in order
     * to let the plug-in know it can now make calls into the scheduler if it
     * needs to.
     * 
     */
    void start();

    /**
     * 
     * Called in order to inform the SchedulerPlugin that it
     * should free up all of it's resources because the scheduler is shutting
     * down.
     * 
     */
    void shutdown();

}