app直播源代码，JavaWeb如何设置定时任务

1.在xml文件中添加监听器

<br><?xml version="1.0" encoding="UTF-8"?><br><web-app version="2.4"<br> xmlns="http://java.sun.com/xml/ns/j2ee"<br> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"<br> xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee<br> http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"><br> <listener><br>  <listener-class>com.tct.test.ContextListener</listener-class><br> </listener><br></web-app><br> 

2.编写定时任务Java代码

<br>package com.tct.test;  <br>    import java.util.Timer;  <br>    import javax.servlet.ServletContextEvent;  <br>    import javax.servlet.ServletContextListener;  <br>    public class ContextListener implements ServletContextListener {  <br>        Timer timer = new Timer() ;  <br>       public void contextInitialized(ServletContextEvent event) {  <br>           timer = new java.util.Timer(true);   <br>           event.getServletContext().log("定时器已启动");           <br>            timer.schedule(new MyTask(event.getServletContext()), 0,1000);   <br>           event.getServletContext().log("已经添加任务调度表");   <br>       }  <br>       public void contextDestroyed(ServletContextEvent event) {  <br>           timer.cancel();  <br>           event.getServletContext().log("定时器以销毁");  <br>       }  <br>   }  <br>   package com.tct.test;  <br>   import java.util.TimerTask;  <br>   import javax.servlet.ServletContext;  <br>   public class MyTask extends TimerTask {  <br>       private static boolean isRunning = false;   <br>       private ServletContext context = null;   <br>       public MyTask(ServletContext servletContext) {  <br>           this.context = servletContext;  <br>       }  <br>       @Override  <br>       public void run() {  <br>         if(!isRunning)  <br>         {  <br>           isRunning = true;  <br>           context.log("开始执行指定任务");   <br>           isRunning = false;  <br>         }  <br>         else  <br>         {  <br>             context.log("上次的任务还未执行完成");  <br>         }  <br>       }  <br>   }  