java web 定时器
来源:互联网 发布:mysql 所有主键 1 编辑:程序博客网 时间:2024/04/27 13:22
java web 定时器收藏
JAVA WEB定时器,定时器的启动一般随web server的启动而启动,一般有两种方法.
方法一:在web.xml里配置一个Servlet,继承HttpServlet,并设置其随web server的启动而启动。然后在该Servlet的init()方法里启动定时器,在destory()方法里销毁定时器。
方法二:在web.xml里配置一个Listener,继承ServletContextListener,然后在该Listener的初始化方法里启动定时器,在其销毁的方法朝左销毁定时器。
一,继承HttpServlet的写法:
1,Servlet
- import java.io.IOException;
- import java.util.Timer;
- import javax.servlet.RequestDispatcher;
- import javax.servlet.ServletContext;
- import javax.servlet.ServletException;
- import javax.servlet.http.HttpServlet;
- import javax.servlet.http.HttpServletRequest;
- import javax.servlet.http.HttpServletResponse;
- import org.apache.commons.lang.StringUtils;
- public class ConvergeDataServlet extends HttpServlet {
- private static final long serialVersionUID = 1L;
- private Timer timer1 = null;
- private Task task1;
- /**
- * Constructor of the object.
- */
- public ConvergeDataServlet() {
- super();
- }
- /**
- * Destruction of the servlet.
- */
- public void destroy() {
- super.destroy();
- if(timer1!=null){
- timer1.cancel();
- }
- }
- public void doGet(HttpServletRequest request, HttpServletResponse response)
- throws ServletException, IOException {
- }
- public void doPost(HttpServletRequest request, HttpServletResponse response)
- throws ServletException, IOException {
- doGet(request, response);
- }
- // init方法启动定时器
- public void init() throws ServletException {
- ServletContext context = getServletContext();
- // (true为用定时间刷新缓存)
- String startTask = getInitParameter("startTask");
- // 定时刷新时间(分钟)
- Long delay = Long.parseLong(getInitParameter("delay"));
- // 启动定时器
- if(startTask.equals("true")){
- timer1 = new Timer(true);
- task1 = new Task(context);
- timer1.schedule(task1, delay * 60 * 1000, delay * 60 * 1000);
- }
- }
- }
2,任务
3,web.xml中的配置
< servlet >
< servlet-name >taskservlet< / servlet-name >
< servlet-class >com.task< /servlet-class >
< init-param >
< param-name >startTask< /param-name >
< param-value >true< /param-value >
< /init-param >
< init-param >
< param-name >intervalTime< /param-name >
< param-value >1< /param-value >
< /init-param >
< load-on-startup >300< /load-on-startup >
< /servlet >
二,继承ServletContextListener
1,定时器
/**
*
*/
package com.annlee.website.util;
import java.util.Timer;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
/**
* @author Administrator 定时器
*/
public class TimerListener implements ServletContextListener {
private Timer timer;
private AnnleeTimerTask task;
public void contextDestroyed(ServletContextEvent arg0) {
timer.cancel();
System.out.println("定时器已销毁");
}
public void contextInitialized(ServletContextEvent event) {
timer = new java.util.Timer(true);
task = new AnnleeTimerTask(event.getServletContext());
System.out.println("定时器已启动");
timer.schedule(task, 0, 60 * 1000);
System.out.println("已经添加任务调度表");
}
}
2,任务
package com.annlee.website.util;
import java.util.Calendar;
import java.util.TimerTask;
import javax.servlet.ServletContext;
import com.annlee.website.model.service.member.UsmAccessDataService;
/**
* 定时器的任务
*/
public class AnnleeTimerTask extends TimerTask {
private ServletContext context;
private static boolean isRunning = false;
private static boolean flag = true;
private static final int C_SCHEDULE_HOUR = 0;
private UsmAccessDataService accessDataService;
public AnnleeTimerTask(ServletContext context){
this.context = context;
}
public void run() {
accessDataService = new UsmAccessDataService();
Calendar cal = Calendar.getInstance();
if (!isRunning) {
if (C_SCHEDULE_HOUR == cal.get(Calendar.HOUR_OF_DAY) && flag) {
isRunning = true;
// accessDataService.SendHttpByMonth(0,0, 0);
System.out.println("正在执行任务");
isRunning = false;
flag = false;
context.log("指定任务执行结束");
}
} else {
context.log("上一次任务执行还未结束");
}
if(C_SCHEDULE_HOUR != cal.get(Calendar.HOUR_OF_DAY)){
flag = true;
}
}
}
3,web.xml中的配置
<listener>
<listener-class>
com.annlee.website.util.TimerListener
</listener-class>
</listener>
- Java定时器Web
- java web 定时器
- java web 定时器用法
- java web 定时器
- java Web定时器
- java Web定时器实例
- JAVA线程定时器(web)
- java WEB中的定时器
- java(web)定时器
- Java定时器Web(转)
- Java定时器Web(转)
- java web 定时器
- java web定时器Timer
- Java定时器Web
- java,web定时器
- Java web实现定时器任务
- jsp (web)定时器,Java定时器在Web中的应用
- Java定时器在Web中的应用
- Java 状态模式(State)
- js没有重载–深入js(2)
- #pragma data_seg用法总结
- GDB 调试基本技巧和指令(一)
- ASP.NET IIS 注册相关命令
- java web 定时器
- ActionScript 3.0的Socket连接的策略文件
- 看到了 喜欢了 摘抄下来了
- 跨域策略文件——解决Flash安全沙箱问题
- Linux下基于C/C++的Socket编程基础
- plsql动态执行存储过程
- C#程序实现动态调用DLL的研究
- 北京我来了
- TCP连接关闭过程笔记