javaWeb中任务调度

package com.application;



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

public class ContextListener implements ServletContextListener {

private java.util.Timer timer = null;

public void contextInitialized(ServletContextEvent event) {
timer = new java.util.Timer(true);
event.getServletContext().log("定时器已启动");
timer.schedule(new TaskTime(event.getServletContext()), 0,
1000); //60 * 60
event.getServletContext().log("已经添加任务调度表");
}

public void contextDestroyed(ServletContextEvent event) {
timer.cancel();
event.getServletContext().log("定时器销毁");
}

}












package com.application;

import java.util.Calendar;
import java.util.TimerTask;

import javax.servlet.ServletContext;

public class TaskTime extends TimerTask {

private static final int C_SCHEDULE_HOUR = 0;
private static boolean isRunning = false;
private ServletContext context = null;

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

public void run() {
Calendar cal = Calendar.getInstance();
if (!isRunning) {
isRunning = true;
context.log("开始执行指定任务");

// TODO 添加自定义的详细任务，以下只是示例
int i = 0;
while (i++ < 10) {
context.log("已完成任务的" + i + "/" + 10);
}

isRunning = false;
context.log("指定任务执行结束");
// if (C_SCHEDULE_HOUR == cal.get(Calendar.HOUR_OF_DAY)) {
// isRunning = true;
// context.log("开始执行指定任务");
//
// // TODO 添加自定义的详细任务，以下只是示例
// int i = 0;
// while (i++ < 10) {
// context.log("已完成任务的" + i + "/" + 10);
// }
//
// isRunning = 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");
}
}

}