Java之几种定时器的使用

没有去仔细研究这两种定时器的API，会使用及能在项目中应用即可；

import org.quartz.CronExpression;
import org.quartz.CronTrigger;
import org.quartz.JobDetail;
import org.quartz.Scheduler;
import org.quartz.SchedulerException;
import org.quartz.SchedulerFactory;
import org.quartz.impl.StdSchedulerFactory;

一、JobDetail的用法

public void startTasl(ServletContext context, String jobName, String jobGroup,
SInterfacePara sInterP, String cexpReg) throws ParseException, SchedulerException {

//创建一个jobDetail对象=>jobName:自定义工作名称；jobGroup自定义工作组名称；启动的类（须实现Job接口）
JobDetail jobDetail = new JobDetail(jobName, jobGroup, SimpleJob.class);

//将所需对象参数放在此Map集合中，后续使用可取出（map.get("key")）
jobDetail.getJobDataMap().put("key", key);

//将servletContext 放置在Map中；
jobDetail.getJobDataMap().put("context", context);

//创建一对触发器对象；
CronTrigger cronTrigger = new CronTrigger("trigger" + jobName, "tgroup" + jobName);

//创建定时任务表达式，将表达式写入其中（此表达式的书写格式，最下面会有详细介绍）；
       CronExpression cexp = new CronExpression("表达式");// ①-2：定义Cron表达式
       cronTrigger.setCronExpression(cexp);// ①-3：设置Cron表达式
       SchedulerFactory schedulerFactory = new StdSchedulerFactory();
       Scheduler scheduler = schedulerFactory.getScheduler();
       scheduler.scheduleJob(jobDetail, cronTrigger);
       scheduler.start();

}

二、实现 StatefulJob 接口

import org.quartz.CronTrigger;
import org.quartz.Job;
import org.quartz.JobDetail;
import org.quartz.Scheduler;
import org.quartz.SchedulerException;
import org.quartz.SchedulerFactory;
import org.quartz.SimpleTrigger;
import org.quartz.Trigger;
import org.quartz.impl.StdSchedulerFactory;

public static void addJob(Task task,ServletContext context) throws SchedulerException, ParseException, InstantiationException, IllegalAccessException, ClassNotFoundException {
           Scheduler sched = sf.getScheduler();
           Job imp = (Job) Class.forName(task.getClassname()).newInstance();//具体的哪个类
           JobDetail jobDetail = new JobDetail(task.getId(), JOB_GROUP_NAME, imp.getClass());//任务名，任务组，任务执行类
           jobDetail.getJobDataMap().put("ServletContext", context);
           //触发器
           Trigger trigger = null;
           if(task.getType()==1){
              trigger = getSimpleTrigger(task);
           }else{
              trigger = getCronTrigger(task);
           }
           sched.scheduleJob(jobDetail,trigger);
           //启动
           if(!sched.isShutdown()){
              sched.start();
           }
       }

public static Trigger getSimpleTrigger(Task task){
       SimpleTrigger trigger = new SimpleTrigger(task.getId(),JOB_GROUP_NAME);
       if(!(task.getStartTime().trim().equals(""))){
           trigger.setStartTime(parseDateString(task.getStartTime()));
       }else{
           trigger.setStartTime(new Date());
       }
       if(!(task.getEndTime().trim().equals(""))){
           trigger.setEndTime(parseDateString(task.getEndTime()));
       }
       if(task.getRepeatCount().equals("-1")){
           trigger.setRepeatCount(SimpleTrigger.REPEAT_INDEFINITELY);
       }else{
           trigger.setRepeatCount(Integer.parseInt(task.getRepeatCount()));
       }
       trigger.setRepeatInterval(Long.parseLong(task.getRepeatInterval())*1000L);
       return trigger;
   }

   public static Trigger getCronTrigger(Task task){
       CronTrigger trigger = new CronTrigger(task.getId(), TRIGGER_GROUP_NAME);//触发器名,触发器组
       try {
           trigger.setCronExpression(task.getContent());
       } catch (ParseException e) {
           e.printStackTrace();
       }//触发器时间设定
       return trigger;
   }

定时的那个类要实现StatefulJob接口

三、线程（自个编写一个线程,在web.xml中启动时优先），下面有个案例，可套用；

1、web.xml添加配置

<servlet-name>MyServlet</servlet-name>
     <servlet-class>my.person.engine.quartz.MyServlet</servlet-class>
     <load-on-startup>0</load-on-startup>
</servlet>

<servlet-mapping>
     <servlet-name>MyServlet</servlet-name>
     <url-pattern>/</url-pattern>
</servlet-mapping>

2、编写一个servlet 继承HttpServlet, 初如化时去启动线程

public void init(ServletConfig config) throws ServletException {
       super.init(config);
       logger.info("初始化了吗");
       try {
            TestSubmit submit = new TestSubmit ();
           submit.start();
       } catch (Exception e) {
           e.printStackTrace();
       }
   }

public class TestSubmit extends Thread {

public void run() {

//利用while循环不断的执行；

代码块注：如果这里执行周期，必须保证线程不会起冲突，否则可能引起数据错误；

}

四、在监听中注册定时，继承TimerTask；

1、先在web.xml中进行注册；

<listener id="Listener_3">
       <listener-class>
           pde.ams.MobileContextListener
       </listener-class>
   </listener>

2、继承上下文监听

public class MobileContextListener implements ServletContextListener {
   private static Logger logger = Logger.getLogger(MobileContextListener.class);
   private Timer timer = null;

   public void contextDestroyed(ServletContextEvent arg0) {
       timer.cancel();
       ProxoolFacade.shutdown();   //连接池关闭
   }

   public void contextInitialized(ServletContextEvent arg0){
       timer = new Timer(true);                        //定时器已启动
//       long delay = 5*1000;                           //5秒后执行
       long delay = 0;
//       long interval = 5*1000 ;                    //定时为每5秒执行一次定时
       long interval=13*1000;//实时发送
       try {
           timer.schedule(new DaiBanSendTaskJob(arg0.getServletContext()), delay, interval);//已经将全文索引添加任务调度表
       } catch (Exception e) {
           timer.cancel();
       }
   }
}

3、继承TimerTask 类

public class DaiBanSendTaskJob extends TimerTask {

public void run() {

｝

Java之几种定时器的使用

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