java 定时任务 （timer和timetask,quartz,spring,LinuxCron）

时间：2021-10-29 07:53:48

</pre>在Java中，实现定时任务有多种方式，，Timer和TimerTask、Spring、QuartZ、Linux Cron。<p></p><p style="margin-top:0px; margin-bottom:0px; padding-top:0px; padding-bottom:0px; font-family:Arial; font-size:14px; line-height:26px">以上4种实现定时任务的方式，Timer是最简单的，不需要任何框架，仅仅JDK就可以，缺点是仅仅是个时间间隔的定时器，调度简单；Spring和QuartZ都支持cron，功能都很强大，Spring的优点是稍微简单一点，QuartZ的优点是没有Spring也可使用；Linux Cron是个操作系统级别的定时任务，适用于所有操作系统支持的语言，缺点是精度只能到达分钟级别。</p><p style="margin-top:0px; margin-bottom:0px; padding-top:0px; padding-bottom:0px; font-family:Arial; font-size:14px; line-height:26px">本文直介绍<span style="font-family:Arial; font-size:14px; line-height:26px">Timer和TimerTask、<span style="font-family:Arial; font-size:14px; line-height:26px">QuartZ</span></span></p><p style="margin-top:0px; margin-bottom:0px; padding-top:0px; padding-bottom:0px; font-family:Arial; font-size:14px; line-height:26px"></p><h1 style="margin:0px; padding:0px; font-family:Arial; line-height:26px">Timer和TimerTask</h1><div></div><pre name="code" class="java">package timertask;

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

public class TimerTest extends TimerTask {

@Override
public void run() {
System.out.println(i++);

}

private Timer timer;
private int i=0;
public static void main(String[] args) {
TimerTest tt=new TimerTest();
tt.timer=new Timer();
tt.timer.schedule(tt, new Date(),1000);
//立刻开始执行timerTest任务，执行完本次任务后，隔2秒再执行一次    
        //timerTest.timer.schedule(timerTest,new Date(),2000);              
        //一秒钟后开始执行timerTest任务，只执行一次    
        //timerTest.timer.schedule(timerTest,1000);              
        //一秒钟后开始执行timerTest任务，执行完本次任务后，隔2秒再执行一次    
        //timerTest.timer.schedule(timerTest,1000,2000);              
        //立刻开始执行timerTest任务，每隔2秒执行一次    
        //timerTest.timer.scheduleAtFixedRate(timerTest,new Date(),2000);             
        //一秒钟后开始执行timerTest任务，每隔2秒执行一次    
        //timerTest.timer.scheduleAtFixedRate(timerTest,1000,2000);    
try {
Thread.sleep(10000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

//结束任务执行，程序终止    
        tt.timer.cancel();    
        //结束任务执行，程序并不终止,因为线程是JVM级别的    
        //timerTest.cancel(); 
System.out.println("你好");
}

}

quartz 的实现。(测试时，需要quartz，slf4j,log4j的架包)

定时任务执行的对象 要继承与job 
package timertask.quartz;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

import org.quartz.Calendar;
import org.quartz.CronExpression;
import org.quartz.CronTrigger;
import org.quartz.Job;
import org.quartz.JobBuilder;
import org.quartz.JobDataMap;
import org.quartz.JobDetail;
import org.quartz.JobExecutionContext;
import org.quartz.JobExecutionException;
import org.quartz.Scheduler;
import org.quartz.SchedulerException;
import org.quartz.SchedulerFactory;
import org.quartz.Trigger;
import org.quartz.impl.StdSchedulerFactory;
import org.quartz.impl.triggers.CronTriggerImpl;

import com.sun.org.apache.bcel.internal.generic.NEW;

public class AutoSendo implements Job{

@Override
public void execute(JobExecutionContext jobexecutioncontext)
throws JobExecutionException {
//定时任务执行的动作。输出数据
String string=(String) jobexecutioncontext.getJobDetail().getJobDataMap().get("key");
System.out.println(string);
//System.out.println("fdsfsdfsdfsd");
}

}

2，执行定时任务

package timertask.quartz;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

import org.bouncycastle.jce.provider.JDKDSASigner.noneDSA;
import org.quartz.CronExpression;
import org.quartz.CronScheduleBuilder;
import org.quartz.CronTrigger;
import org.quartz.Job;
import org.quartz.JobBuilder;
import org.quartz.JobDetail;
import org.quartz.JobKey;
import org.quartz.Scheduler;
import org.quartz.SchedulerException;
import org.quartz.SchedulerFactory;
import org.quartz.TriggerBuilder;
import org.quartz.impl.StdSchedulerFactory;
import org.quartz.impl.triggers.CronTriggerImpl;

public class QuartzSchedulerUtil {

public static void launchTask() throws Exception{
SchedulerFactory factory =new StdSchedulerFactory();
//一种，cronTrigger获得方式一
CronTriggerImpl cronTrigger=new CronTriggerImpl();
SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
//第二种cronTrigger的获得方式
//cronTrigger=TriggerBuilder.newTrigger().withIdentity("sss").withSchedule(CronScheduleBuilder.cronSchedule("0/2 * * * * ?")).build();
cronTrigger.setCronExpression("0/30 * * * * ? ");
cronTrigger.setName("sssss");
cronTrigger.setStartTime(new Date());
Class<Job> job1=(Class<Job>) Class.forName("timertask.quartz.AutoSendo");
System.out.println(job1.newInstance());
JobBuilder jb= JobBuilder.newJob(job1).withIdentity("sssssss");
jb.usingJobData("key", "value");
JobDetail job=jb.build();
Scheduler scheduler=factory.getScheduler();
Date date =scheduler.scheduleJob(job, cronTrigger);
System.out.println(sdf.format(date)); 
scheduler.start();
//立即发送方法
scheduler.triggerJob(job.getKey());;
//停止定时任务
scheduler.unscheduleJob(cronTrigger.getKey());
}
public static void main(String[] args)  throws Exception {
QuartzSchedulerUtil.launchTask();
}
}




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