Java中定时任务的兑现

Java中定时任务的实现

1. 建立TimerTask

 

package com.yingxia.asset.server.message_notice;

import java.util.Date;
import java.util.TimerTask;

public class MessageTask extends TimerTask {

	@SuppressWarnings("deprecation")
	@Override
	public void run() {

		System.out.println(new Date().toLocaleString() + "执行短信任务");
	}

}

 

2. 建立ServletContextListener

 

package com.yingxia.asset.server.message_notice;

import java.util.Date;
import java.util.Timer;

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

import com.yingxia.server.commom.FileReader;

public class MessageTaskListener implements ServletContextListener {

	private Timer timer = null;
	
	@Override
	public void contextDestroyed(ServletContextEvent sce) {
		timer.cancel();
		System.out.println("短信任务定时器停止");
	}

	@SuppressWarnings("deprecation")
	@Override
	public void contextInitialized(ServletContextEvent sce) {
		
		// 86400000 毫秒 = 1天
		Date d = new Date(new Date().getTime() + 86400000);
		String[] strs = readFirstLine().split(":");
		d.setHours(Integer.valueOf(strs[0]));
		d.setMinutes(Integer.valueOf(strs[1]));
		d.setSeconds(0);
		System.out.println("短信任务的启动时间：" + d.toLocaleString());
		
		timer = new Timer(true);
		timer.schedule(new MessageTask(), d, 86400000);
	}
	
	private String readFirstLine() {
		return FileReader.getFirstLine("com/yingxia/asset/server/message_notice/SetTime");
	}

}

 

3. 配置web.xml

 

	<!-- 短信listener -->
	<listener>
		<listener-class>com.yingxia.asset.server.message_notice.MessageTaskListener</listener-class>
	</listener>