Quartz 框架的应用

本文将简单介绍在没有 Spring 的时候..如何来使用 Quartz...

这里跳过 Quartz 的其他介绍。如果想更加输入的了解 Quartz，大家可以点击下载Quartz的帮助文档。

Quartz 和 Web 集成应用

第一步： 导入quartz包..这个不用说吧..放到工程的 lib 下面即可

第二步： 添加相应文件和修改web.xml文件的配置.

添加 quartz.properties 和 quartz_jobs.xml 到 src 下面

quartz.properties文件如下：

#----------调度器属性-------------
org.quartz.scheduler.instanceName = QuartzScheduler
org.quartz.scheduler.instanceId = AUTO

#------------线程配置------------------
org.quartz.threadPool.class = org.quartz.simpl.SimpleThreadPool
org.quartz.threadPool.threadCount = 5
org.quartz.threadPool.threadPriority = 5

#---------------作业存储设置---------------
org.quartz.jobStore.class=org.quzrtz.simpl.RAMJobStore

#---------------插件配置----------------

org.quartz.plugin.jobInitializer.class = org.quartz.plugins.xml.JobInitializationPlugin
org.quartz.plugins.xml.JobInitializationPlugin = quartz_jobs.xml     

org.quartz.plugin.jobInitializer.overWriteExistingJobs = false
org.quartz.plugin.jobInitializer.validating = false
org.quartz.plugin.jobInitializer.failOnFileNotFound =true  

quartz_jobs.xml 文件如下

<?xml version="1.0" encoding="UTF-8"?>
<quartz>
    <job>  

        <job-detail>
            <name>GatherJob</name>
            <group>DEFAULT</group>
            <description>GatherJob</description>
            <job-class>net.sf.rain.gather.quartz.GatherJob</job-class>
            <volatility>false</volatility>
            <durability>false</durability>
            <recover>false</recover>
        </job-detail>  

        <trigger>
            <cron>
                <name>RunQuartzJobTrigger</name>
                <group>DEFAULT</group>
                <description>RunQuartzJobTrigger</description>
                <job-name>RunQuartzJob</job-name>
                <job-group>DEFAULT</job-group>
                <!--  <cron-expression>0/60 * * * * ?</cron-expression> -->
                <cron-expression>0 0 3 * * ?</cron-expression>
            </cron>
        </trigger>  

    </job>
</quartz>  

注意文件中的配置要正确。比如 job-class 等等。

web.xml的配置：

从 2.3 版本的 Servlet API 开始，你能创建监听器，由容器在其生命周期中的某个特定时间回调。其中的一个监听器接口叫做 java.servlet.ServletContextListener，

WEB.xml

<!-- ====================== Quartz config start ====================== -->
<context-param>
    <param-name>config-file</param-name>
    <param-value>/quartz.properties</param-value>
</context-param>  

<context-param>
    <param-name>shutdown-on-unload</param-name>
    <param-value>true</param-value>
</context-param>  

<context-param>
    <param-name>start-scheduler-on-load</param-name>
    <param-value>true</param-value>
</context-param>
<!-- 默认情况下配置 Quzrtz 自带的监听器..但是真正项目开发中。我们是否开启定时任务应该是人工配置，所以我们需要自定义监听器 -->
<!--
<listener>
        <listener-class>org.quartz.ee.servlet.QuartzInitializerListener</listener-class>
   </listener>
-->
<listener>
   <listener-class>
        net.sf.rain.gather.quartz.QuartzServletContextListener
   </listener-class>
</listener>   

<!-- ====================== Quartz config end ====================== -->  

下面我们将实现这个监听器   QuartzServletContextListener

package net.sf.rain.gather.quartz;  

import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;  

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.quartz.SchedulerException;
import org.quartz.impl.StdSchedulerFactory;  

public class QuartzServletContextListener implements ServletContextListener {  

    private static  Log _log = LogFactory.getLog(QuartzServletContextListener.class);  

    public static final String QUARTZ_FACTORY_KEY = "org.quartz.impl.StdSchedulerFactory.KEY";
    private ServletContext ctx = null;
    private StdSchedulerFactory factory = null;  

    /**
     * Called when the container is shutting down.
     */
    public void contextDestroyed(ServletContextEvent sce) {
        try {
            factory.getDefaultScheduler().shutdown();
        } catch (SchedulerException ex) {
            _log.error("Error stopping Quartz", ex);
        }
    }  

    /**
     * 容器的第一次启动时调用
     */
    public void contextInitialized(ServletContextEvent sce) {
        ctx = sce.getServletContext();
        try {
            factory = new StdSchedulerFactory();
            // Start the scheduler now
            //设置容器启动时不立即启动定时器，而是到后台人工启动
            //factory.getScheduler().start();
            _log.info("Storing QuartzScheduler Factory at" + QUARTZ_FACTORY_KEY);
            ctx.setAttribute(QUARTZ_FACTORY_KEY, factory);  

        } catch (Exception ex) {
            _log.error("Quartz failed to initialize", ex);
        }
    }  

}  

下面的Action将管理定时器的状态

package net.sf.rain.gather.quartz;  

import java.io.PrintWriter;  

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;  

import org.apache.commons.lang.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.quartz.Scheduler;
import org.quartz.SchedulerException;
import org.quartz.impl.StdSchedulerFactory;  

/**
 *
 * 调度器管理
 *
 * @author
 *
 */
public class GatherJobAction extends  Action{  

    private static  Log _log = LogFactory.getLog(GatherJobAction.class);  

    public ActionForward execute(ActionMapping mapping, ActionForm form,
            HttpServletRequest request, HttpServletResponse response)
            throws Exception {  

        request.setCharacterEncoding("UTF-8");
        response.setContentType("text/html;charset=UTF-8");  

        String action = request.getParameter("action");  

        String retMsg = "Parameter Error: action is null";
        if (StringUtils.isNotBlank(action)) {
            ServletContext ctx =  request.getSession().getServletContext();
            // Retrieve the factory from the ServletContext
            StdSchedulerFactory factory =  (StdSchedulerFactory)ctx.getAttribute(QuartzServletContextListener.QUARTZ_FACTORY_KEY);
            // Retrieve the scheduler from the factory
            Scheduler scheduler = factory.getScheduler();   

            if ("start".equals(action)) {
                // Start the scheduler
                try {
                     if (!scheduler.isStarted()) {
                         scheduler.start();
                     }
                     retMsg = "Quartz Successful to startup";
                 } catch (SchedulerException ex) {
                     _log.error("Error starting Quartz", ex);
                     retMsg = "Quartz failed to startup";
                 }
            }else if("stop".equals(action)){
                try {
                    if (scheduler.isStarted()) {
                        scheduler.shutdown();
                    }
                    retMsg = "Quartz Successful to stopping";
                 } catch (SchedulerException ex) {
                    _log.error("Error stopping Quartz", ex);
                    retMsg = "Quartz failed to stopping";
                 }
            }else { //查看调度器的状态
                if (scheduler.isStarted()) {
                    retMsg = "Quartz is Started";
                }else {
                    retMsg = "Quartz is Stoped";
                }
            }
        }
        PrintWriter out = response.getWriter();
        out.print(retMsg);
        out.flush();
        out.close();
        return null;
    }
}