Spring Scheduling Annotations

@EnableAsync

With this annotation, we can enable asynchronous functionality in Spring.

We must use it with @Configuration:

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@Configuration @EnableAsync class VehicleFactoryConfig {}

Now, that we enabled asynchronous calls, we can use @Async to define the methods supporting it.

@EnableScheduling

With this annotation, we can enable scheduling in the application.

We also have to use it in conjunction with @Configuration:

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@Configuration @EnableScheduling class VehicleFactoryConfig {}

As a result, we can now run methods periodically with @Scheduled.

@Async

We can define methods we want to execute on a different thread, hence run them asynchronously.

To achieve this, we can annotate the method with @Async:

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@Async void repairCar() {     // ... }

If we apply this annotation to a class, then all methods will be called asynchronously.

Note, that we need to enable the asynchronous calls for this annotation to work, with @EnableAsync or XML configuration.

@Scheduled

If we need a method to execute periodically, we can use this annotation:

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@Scheduled(fixedRate = 10000) void checkVehicle() {     // ... }

We can use it to execute a method at fixed intervals, or we can fine-tune it with cron-like expressions.

@Scheduled leverages the Java 8 repeating annotations feature, which means we can mark a method with it multiple times:

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@Scheduled(fixedRate = 10000) @Scheduled(cron = "0 * * * * MON-FRI") void checkVehicle() {     // ... }

Note, that the method annotated with @Scheduled should have a void return type.

Moreover, we have to enable scheduling for this annotation to work for example with @EnableScheduling or XML configuration.

@Schedules

We can use this annotation to specify multiple @Scheduled rules:

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@Schedules({   @Scheduled(fixedRate = 10000),   @Scheduled(cron = "0 * * * * MON-FRI") }) void checkVehicle() {     // ... }

Note, that since Java 8 we can achieve the same with the repeating annotations feature as described above.