弹簧引导启动线程同时用于计划服务

Question

I have a single component which scheduled with a fixedDealy [ 20 second ]. Sample code snippet is as follows :

@Scheduled(fixedDelayString = "20000")
@Async("specificTaskExecutor")
public void scheduleTaskWithFixedDelay() {
    logger.info("Fixed Dealy Task :: Execution Time - {}", 
    dateTimeFormatter.format(LocalDateTime.now()));
}

My ThreadPoolTaskExecutor looks like this:

@Bean(name = "specificTaskExecutor")
public TaskExecutor specificTaskExecutor() {
    ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
    executor.setCorePoolSize(10);
    executor.setMaxPoolSize(10);
    executor.setThreadNamePrefix("test-");
    executor.initialize();
    return executor;
}

When i run my application, i see the result as follows :

2019-01-23 23:29:48.084  INFO 47607 --- [         test-1] c.e.s.initial_code.ScheduledTasks        : Fixed Delay Task :: Execution Time - 23:29:48
2019-01-23 23:30:08.068  INFO 47607 --- [         test-2] c.e.s.initial_code.ScheduledTasks        : Fixed Delay Task :: Execution Time - 23:30:08
2019-01-23 23:30:28.074  INFO 47607 --- [         test-3] c.e.s.initial_code.ScheduledTasks        : Fixed Delay Task :: Execution Time - 23:30:28
2019-01-23 23:30:48.080  INFO 47607 --- [         test-4] c.e.s.initial_code.ScheduledTasks        : Fixed Delay Task :: Execution Time - 23:30:48
2019-01-23 23:31:08.083  INFO 47607 --- [         test-5] c.e.s.initial_code.ScheduledTasks        : Fixed Delay Task :: Execution Time - 23:31:08
2019-01-23 23:31:28.084  INFO 47607 --- [         test-6] c.e.s.initial_code.ScheduledTasks        : Fixed Delay Task :: Execution Time - 23:31:28
2019-01-23 23:31:48.087  INFO 47607 --- [         test-7] c.e.s.initial_code.ScheduledTasks        : Fixed Delay Task :: Execution Time - 23:31:48
2019-01-23 23:32:08.091  INFO 47607 --- [         test-8] c.e.s.initial_code.ScheduledTasks        : Fixed Delay Task :: Execution Time - 23:32:08
2019-01-23 23:32:28.092  INFO 47607 --- [         test-9] c.e.s.initial_code.ScheduledTasks        : Fixed Delay Task :: Execution Time - 23:32:28
2019-01-23 23:32:48.092  INFO 47607 --- [        test-10] c.e.s.initial_code.ScheduledTasks        : Fixed Delay Task :: Execution Time - 23:32:48
2019-01-23 23:33:08.098  INFO 47607 --- [         test-1] c.e.s.initial_code.ScheduledTasks        : Fixed Delay Task :: Execution Time - 23:33:08

Looks like the threads are being fired up with a delay of 20 seconds. Is there any way i can start off all the threads at once?

Could anyone let me know how this can be achieved?

Answer 1

I think this is what you are asking for

@Scheduled(fixedRate = 20000)
@Async("specificTaskExecutor")
public void scheduleTaskWithFixedDelay() {
    logger.info("Fixed Dealy Task :: Execution Time - {}", 
    dateTimeFormatter.format(LocalDateTime.now()));
}

Instead of using fixedDelayString property use fixedRate.

The fixedDelay property makes sure that there is a delay of n millisecond between the finish time of an execution of a task and the start time of the next execution of the task.

While the fixedRate property runs the scheduled task at every n millisecond. It doesn't check for any previous executions of the task.