Java Servlet任务触发器

进程停止，由此进程启动的线程也会停止；

一、触发器类

package my.test

import java.util.Timer;

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

/**
* 任务触发器,Tomcat启动时
*
* @author Administrator
*
*/
public class TaskTrigger implements ServletContextListener
{
private Timer timer = null;
private TaskThread task = null;

public void contextInitialized(ServletContextEvent event)
{
  //初始化监听器，在tomcat启动的时候监听器启动
   timer = new Timer(true);
   task = TaskThread.GetTaskThread(event.getServletContext());
   timer.schedule(task, 1000);//延迟1s后执行，当然也可以定时循环执行，请自己查看Timer类的说明
   log.info("启动任务进程************");
}

public void contextDestroyed(ServletContextEvent event)
{
   //关闭监听器
   timer.cancel();
   log.info("关闭任务进程************");
}
}


二、任务类，必须继承java.util.TimerTask类

package my.test

public class TaskThread extends TimerTask
{
public static TaskThread taskThread = null;
@SuppressWarnings("unused")
private ServletContext context = null;

public TaskThread(ServletContext context)
{
   this.context = context;
}

public static TaskThread GetTaskThread(ServletContext context)
{
   if(taskThread ==null)
    taskThread = new TaskThread(context);
   return taskThread ;
}

public void run()
{
// 在此添加要执行的任务

}
}

三、在web.xml中添加

<listener>
<listener-class>my.test.TaskTrigger</listener-class>
</listener>