Schedule Task

The cron expression was added after the Blade 2.0.8 version to complete the task of timing the task. You only need to add a @Schedule annotation to the method that handles the task, and then write the cron expression.

Blade’s mission system provides an API for creating, stopping, and getting task lists.

Create task

@Bean
public class SimpleTask {

   @Schedule(cron = "* * * * * ?")
    public void syncRelate() {
        System.out.println("executed");
    }

}

This will create a scheduled task that is executed every second. The name of the scheduled task created at this time is task-0, when you don’t specify a task name, the system will name them starting from 0 in numerical order, if you want to be dynamic.

To turn them off, be sure to add name to the @Schedule annotation to name it, like this.

@Bean
public class SimpleTask {

   @Schedule(name = "task1", cron = "* * * * * ?")
    public void syncRelate() {
        System.out.println("execute once");
    }

}

TaskManager

The task can be managed by calling the static method of TaskManager. The following is the API of TaskManager.

• getTask(name): Get a task based on the task name.
• getTasks(): Get all tasks of the system
• stopTask(name): Stop a running task based on the task name

The way to close a task is implemented inside Task, each task will have a context, you see in the previous creation task Each method has no parameters, and Blade supports you to pass a parameter of type TaskContext to manipulate the current task. (may not be used in most cases).

private AtomicInteger run1 = new AtomicInteger();

@Schedule(cron = "* * * * * ?")
public void run1(TaskContext context) {
    if (run1.get() == 5) {
        context.stop();
        return;
    }
    run1.getAndIncrement();
    log.info(LocalDateTime.now() + ": Hello task1. " + Thread.currentThread());
}

This way you can close a task when a condition is triggered.

Common Cron expressions

• */5 * * * * ?: Execute every 5 seconds
• 0 */1 * * * ?: Execute every 1 minute
• 0 0/5 * * * ?: Execute every 5 minutes
• 0 0 23 * * ?: Execute once every day at 23
• 0 0 1 * * ?: Execute once a day at 1am
• 0 0 1 1 * ?: Execute once a day at 1 am on the 1st of the month
• 0 0 23 L * ?: Execute once at 23 o’clock on the last day of each month
• 0 0 1 ? * L: Implemented once a week on Sunday at 1 am
• 0 26,29,33 * * * ?: Execute once at 26, 29, and 33
• 0 0 0,13,18,21 * * ?: Execute once every day at 0, 13, 18, and 21
• 0 0 12 * * ?: Trigger every day at 12 noon
• 0 15 10 ? * *: Trigger every day at 10:15 am
• 0 15 10 * * ?: Trigger every day at 10:15 am
• 0 15 10 * * ? *: Trigger every day at 10:15 am
• 0 15 10 * * ? 2005: Every day at 10:15 am in 2005
• 0 * 14 * * ?: Trigger every 1 minute between 2 pm and 2:59 pm
• 0 0/5 14 * * ?: Trigger every 5 minutes between 2 pm and 2:55 pm
• 0 0/5 14,18 * * ?: Trigger every 5 minutes between 2 pm and 2:55 pm and 6 pm to 6:55 pm
• 0 0-5 14 * * ?: Trigger every 1 minute between 2 pm and 2:05 pm
• 0 10,44 14 ? 3 WED: Triggered at 2:10 pm and 2:44 pm on Wednesday of March each year
• 0 15 10 ? * MON-FRI: Triggered at 10:15 am Monday to Friday
• 0 15 10 15 * ?: Trigger at 10:15 am on the 15th of each month
• 0 15 10 L * ?: Trigger at 10:15 am on the last day of each month
• 0 15 10 ? * 6L: Trigger at 10:15 am on the last Friday of each month
• 0 15 10 ? * 6L 2002-2005: Trigger at 10:15 am on the last Friday of each month from 2002 to 2005
• 0 15 10 ? * 6#3: Trigger at 10:15 am on the third Friday of each month
• 0 15 10 ? * 6#3: Trigger at 10:15 am on the third Friday of each month

online cron generator.