java定时器timer的使用方法代码示例

  com.dcits.app.servlet.MyTimerTaskListener

package com.dcits.app.servlet;
import java.util.Calendar;
import java.util.Timer;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
/**
 * @author Weiyongle
 * @time 2017-5-5 下午2:05:32
 */
public class MyTimerTaskListener implements ServletContextListener {
	private Timer timer = null;
	@Override
	  public void contextDestroyed(ServletContextEvent arg0) {
		timer.cancel();
	}
	@Override
	  public void contextInitialized(ServletContextEvent arg0) {
		System.out.println("-----开始启动定时器------");
		Calendar twentyOne= Calendar.getInstance();
		twentyOne.set(Calendar.HOUR_OF_DAY, 23);
		twentyOne.set(Calendar.MINUTE, 0);
		twentyOne.set(Calendar.SECOND, 0);
		timer = new Timer(true);
		//第一次是晚上23点执行，间隔24小时执行一次
		timer.schedule(new MyTimerTask(), twentyOne.getTime(), 1000*60*60*24);
		//*System.out.println("-----开始启动定时器------");
    Calendar twentyOne= Calendar.getInstance();
    twentyOne.set(Calendar.HOUR_OF_DAY, 14);
    twentyOne.set(Calendar.MINUTE, 47);
    twentyOne.set(Calendar.SECOND, 0);
    timer = new Timer(true);
    timer.schedule(new MyTimerTask(), twentyOne.getTime(), 1000*10);*/
	}
}

package com.dcits.app.servlet;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import java.util.TimerTask;
import org.codehaus.jackson.JsonGenerationException;
import org.codehaus.jackson.map.JsonMappingException;
/**
 * 定时器，用于补偿认证的时候没有获取到正常返回的那些数据
 * @author Weiyongle
 * @time 2017-5-5 下午2:20:12
 */
public class MyTimerTask extends TimerTask{
	private static StringBuffer url = new StringBuffer();
	@Override
	  public void run() {
		//生产环境
		//    url.append("https://我是具体的ip地址/nmsypt/servlet/webServlet");//生产环境
		url.append("http://localhost:8080/adp/servlet/webServlet");
		//本地环境
		Map reqMap = new HashMap();
		//这里的map从数据库里获取对应的数据不写死就行了,先获取map，在写个for循环进行循环就行了
		reqMap.put("QYMC","丹同学的公司");
		reqMap.put("NSRSBH","158028307441234");
		reqMap.put("SJHM_FR","15802830744");
		reqMap.put("YZM","123456");
		reqMap.put("CWFZR","");
		//
		reqMap.put("ZJLX_DM_CW","");
		//
		reqMap.put("ZJHM_CW","");
		//
		reqMap.put("ZGRS","1234");
		reqMap.put("SQYY","");
		//
		reqMap.put("JRCPBM","00002");
		reqMap.put("XYDM","1");
		reqMap.put("XZQHDM","");
		reqMap.put("QYBM","QY17900000647001");
		try {
			CompensateData.CompensateDatas(url.toString(), reqMap);
			System.out.println("-----成功补偿了一条认证信息------");
		}
		catch (JsonGenerationException e) {
			e.printStackTrace();
		}
		catch (JsonMappingException e) {
			e.printStackTrace();
		}
		catch (IOException e) {
			e.printStackTrace();
		}
	}
}

package com.wang.reflect;
import java.io.File;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Timer;
import java.util.TimerTask;
class MyTask extends TimerTask{
/**
 * 定时删除指定位置的文件,(这里以删除f盘下aa文件夹的所有文件为例)
 */
  @Override
  public void run() {
    File file=new File("f://aa");
    deleteFolder(file);
  }
  public void deleteFolder(File file){
    File[] files=file.listFiles();
    for(File f:files){
      if(f.isDirectory()){
        //使用递归
        deleteFolder(f);
      }else{
        f.delete();
      }
    }
    file.delete();
  }
}
public class TimerDemo {
  public static void main(String[] args) throws ParseException {
    //创建定时器对象
    Timer t=new Timer();
    String time="2016-04-04 11:26:40";
    Date d=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").parse(time);
    t.schedule(new MyTask(), d);
  }
}