ScheduledExecutorService使用_scheduledexecutorservice的使用

什么是ScheduledExecutorService？

ScheduledExecutorService是基于线程池的定时任务类，每个调度的任务都会分配到线程池中到一个线程去执行，即任务是并发执行的，互不影响，只有当调度任务来的时候，ScheduledExecutorService才会真正启动一个线程，其余时间ScheduledExecutorService都是处于轮询任务的状态。

ScheduledExecutorService执行方式？

public interface ScheduledExecutorService extends ExecutorService {

    /**
     * 创建一个到达指定延迟时间执行的任务
     */
    public ScheduledFuture<?> schedule(Runnable command,
                                       long delay, TimeUnit unit);
    /**
     * 创建一个到达指定延迟时间执行的ScheduledFuture
     */
    public <V> ScheduledFuture<V> schedule(Callable<V> callable,
                                           long delay, TimeUnit unit);

    /**
     * 每次执行时间为上一次任务开始起向后推一个时间间隔
     */
    public ScheduledFuture<?> scheduleAtFixedRate(Runnable command,
                                                  long initialDelay,
                                                  long period,
                                                  TimeUnit unit);
    /**
     * 每次执行时间为上一次任务结束起向后推一个时间间隔
     */
    public ScheduledFuture<?> scheduleWithFixedDelay(Runnable command,
                                                     long initialDelay,
                                                     long delay,
                                                     TimeUnit unit);
}


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

ScheduledExecutorService简单使用

public class ExecutorServiceDemo {

    private static ScheduledExecutorService scheduledExecutorServicePool = new ScheduledThreadPoolExecutor(10
            , r -> new Thread(r, "executor-service-pool-" + r.hashCode()));


    /**
     * 创建一个到达指定延迟时间执行的任务
     */
    public static void scheduleWithRunnable() {
        scheduledExecutorServicePool.schedule(() -> System.out.println("scheduleWithRunnable Task")
                , 5, TimeUnit.SECONDS);
        scheduledExecutorServicePool.shutdown();
    }

    /**
     * 创建一个到达指定延迟时间执行的ScheduledFuture
     */
    public static void scheduleWithCallable() {
        scheduledExecutorServicePool.schedule((Callable) () -> doSomeThing()
                , 5, TimeUnit.SECONDS);
        scheduledExecutorServicePool.shutdown();
    }

    private static String doSomeThing() {
        System.out.println("scheduleWithCallable Task");
        return "scheduleWithCallable Task";
    }

    /**
     * 每次执行时间为上一次任务开始起向后推一个时间间隔
     */
    public static void scheduleAtFixedRate() {
        scheduledExecutorServicePool.scheduleAtFixedRate(() -> {
            System.out.println("scheduleAtFixedRate Task" + System.currentTimeMillis());
            try {
                Thread.sleep(10000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }, 1, 5, TimeUnit.SECONDS);
    }

    /**
     * 每次执行时间为上一次任务结束起向后推一个时间间隔
     */
    public static void scheduleWithFixedDelay() {
        scheduledExecutorServicePool.scheduleWithFixedDelay(() -> {
            System.out.println("scheduleWithFixedDelay Task" + System.currentTimeMillis());
            try {
                Thread.sleep(10000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }, 1, 5, TimeUnit.SECONDS);
    }

    public static void main(String[] args) {
        //scheduleWithRunnable();
        //scheduleWithCallable();
        scheduleAtFixedRate();
        //scheduleWithFixedDelay();
    }
}


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
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66

ScheduledExecutorService整合SpringBoot

@Configuration
public class ScheduleConfig {

    @Bean
    public ScheduledExecutorService taskScheduler() {
        return new ScheduledThreadPoolExecutor(1);
    }

}
1
2
3
4
5
6
7
8
9

ScheduledExecutorService工具类

@Slf4j
public class JobUtils {

    @Resource
    private static ScheduledExecutorService scheduler;
    private static final ConcurrentMap<String, ScheduledFuture> timingTaskMap = new ConcurrentHashMap<>();
    private static final Map<Long, String> taskHistorical = new HashMap<>();

    // private static final ScheduledExecutorService scheduler = Executors.newScheduledThreadPool(1);

    /**
     * 创建一个定时任务
     * @param taskName     任务名称
     * @param initialDelay 延时开始
     * @param period       执行周期
     * @param command      任务线程
     * @param mandatory    (存在)强制创建
     */
    public static boolean CreateTimingTask(String taskName, long initialDelay,
                                           long period, Runnable command, boolean mandatory) {
        if (FindTimingTask(taskName)) {
           log.info("定时任务存在");
            if (mandatory) {
                log.info("强制创建");
                CancelTimingTask(taskName);
                ScheduledFuture future = scheduler.scheduleAtFixedRate(command, initialDelay, period, TimeUnit.MINUTES);
                timingTaskMap.put(taskName, future);
                return  true;
            } else {
                return false;
            }
        }
        ScheduledFuture future = scheduler.scheduleAtFixedRate(command, initialDelay, period, TimeUnit.MINUTES);
        timingTaskMap.put(taskName, future);
        return true;
    }

    /**
     * 创建一个一次性的延迟任务
     * @param initialDelay 延时开始
     * @param command      任务线程
     */
    public static void CreateTask(String name, long initialDelay, Runnable command) {
        try {
            scheduler.schedule(command, initialDelay, TimeUnit.MINUTES);
            taskHistorical.put(System.currentTimeMillis(), name);
        } catch (Exception e) {
           log.info("任务执行失败");
        }
    }

    /**
     * 根据名称查询定时任务
     * @param taskName 任务名称
     * @return true任务存在  false任务取消
     */
    public static boolean FindTimingTask(String taskName) {

        try {
            ScheduledFuture scheduledFuture = timingTaskMap.get(taskName);
            if (scheduledFuture != null) {
                return true;
            }
        } catch (Exception e) {
            return false;
        }
        return false;
    }

    /**
     * 查询定时任务列表
     * @return 任务名称集合
     */
    public static Set<String> FindListTimingTask() {
        return timingTaskMap.keySet();
    }

    /**
     * 根据名称取消定时任务
     * @param taskName 任务名称
     */
    public static boolean CancelTimingTask(String taskName) {
        try {
            if (FindTimingTask(taskName)) {
                boolean b = timingTaskMap.get(taskName).cancel(true);
                timingTaskMap.remove(taskName);
                return b;
            }
        } catch (Exception e) {
            return false;
        }
        return false;
    }
}

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
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95