好得很程序员自学网

<tfoot draggable='sEl'></tfoot>

java的几种定时器的具体使用(4种)

总结一下我使用过的4种类型的定时器:@Scheduled注解、quartz、new Timer().schedule、使用线程控制。

1.@Scheduled注解

@Scheduled注解是最简单的方式,只需要启用定时器,在方法上添加注解即可。

在spring配置中加入:

?

1

2

3

4

5

6

7

8

<!-- 启用注解定时器 -->

  < task:annotation-driven />

在要具体的方法上加入注解@Scheduled

 

@Scheduled(cron = "0 0 * * * ? ")

     public void myTask(){

            //定时任务......

}

2.quartz

quartz使用的是可配置的方式,将所有的定时器都配置再一个xml文件里面。步骤如下:

1.创建一个spring的配置文件:spring-quartz.xml

2.定义工作任务的job

3.定义触发器Trigger并与job绑定

4.定义调度器,并将Trigger注册到scheduler

?

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

< bean id = "myTask" class = "cn.coolwind.MyTask" />

  <!-- 1.定义工作任务job -->

     < bean id = "testJob" class = "org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean" >

         <!-- 定时器的类  -->

         < property name = "targetObject" ref = "myTask" ></ property >

         <!-- 需要定时执行的方法  -->

         < property name = "targetMethod" value = "test" ></ property >

         < property name = "concurrent" value = "false" ></ property >

     </ bean >

     <!-- 2.定义触发器Trigger并与Job绑定 -->

     < bean id = "testJobTrigger" class = "org.springframework.scheduling.quartz.CronTriggerFactoryBean" >

         < property name = "jobDetail" ref = "testJob" />

         <!-- 根据需要设置定时执行的时间 -->

         < property name = "cronExpression" value = "0 0/5 * * * ?" />

     </ bean >

 

    <!-- 3.定义调度器,并将trigger注册进去 -->

< bean name = "quartzScheduler" class = "org.springframework.scheduling.quartz.SchedulerFactoryBean" >

         < property name = "triggers" >

             < list >

                  < ref local = "testJobTrigger" />

             </ list >

         </ property >

     </ bean >

最后记得将xml写入web.xml里!

?

1

2

3

4

5

6

7

8

< init-param >

    < param-name >contextConfigLocation</ param-name >

    < param-value >

  classpath:applicationContext.xml,

  classpath:log4j.xml,

              classpath:spring-quartz.xml

</ param-value >

  </ init-param >

3.使用Timer

使用Timer的schedule,schedule有3个参数:

schedule(TimerTask task, long delay, long period)
第一个为定时任务,根据业务需要重写TimerTask的run方法即可;

第二个为延时启动,单位毫秒;

第三个位多久运行一次,单位毫秒;

?

1

2

3

4

5

6

7

8

9

10

new Timer().schedule( new TimerTask() {

             @Override

             public void run() {

                 try {

                     //do Something

                 } catch (Exception e) {

                     e.printStackTrace();

                 }

             }

         }, 0 ,5L * 60 * 1000 );

4.使用线程控制

使用线程来控制就更灵活一些,可以根据自己的需要判断什么时候运行,什么时候停止,这需要对java的线程有一定的了解。

?

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

public class TaskTest {

     private static final ExecutorService pool = Executors.newFixedThreadPool( 5 ); // 线程池

     public static final TaskTest me = new TaskTest();

     public final int [] arr = new int []{ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 };

 

     public static void main(String[] args) {

         me.start();

     }

 

     private void start() {

         pool.execute( new Runnable() {

             @Override

             public void run() {

                 while ( true ) {

                     try {

                         for ( int i = 0 ; i < arr.length; i++) {

                             if ( 1 == arr[i]) {

                                 System.out.println( "start!" );

                                 Thread.sleep( 1 *1000L);

                             }

                             if ( 6 == arr[i]) {

                                 System.out.println( "stop!" );

                                 Thread.sleep( 5 *1000L);

                             }

                             System.out.println(arr[i]);

                             if ( 9 == arr[i]) {

                                 System.out.println( "end!" );

                                 Thread.sleep( 5 *1000L);

                             }

                         }

                     } catch (InterruptedException e) {

                         e.printStackTrace();

                     }

                 }

             }

         });

     }

}

到此这篇关于java的几种定时器的具体使用(4种)的文章就介绍到这了,更多相关java 定时器内容请搜索以前的文章或继续浏览下面的相关文章希望大家以后多多支持!

原文链接:https://blog.csdn.net/coolwindd/article/details/82804189

查看更多关于java的几种定时器的具体使用(4种)的详细内容...

  阅读:14次