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

</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 {@Overridepublic 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 blocke.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{@Overridepublic 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();}}