Spring Async

In this section, we will see the asynchronous execution support in Spring. In certain cases, we need to execute some tasks asynchronously, because the result of that task does not require the user, so we can process that task in a separate thread. The main benefit of asynchronous programming is that we can increase the performance and responsiveness of our application.

Spring provides annotation support for asynchronous method execution via @EnableAsync and @Async. Let's discuss them in detail.

The @EnableAsync annotation

We can enable asynchronous processing by simply adding @EnableAsync to a configuration class, as follows:

@Configuration
@EnableAsync
public class AppConfig {
  @Bean
  public AsyncTask asyncTask() {
    return new AsyncTask();
  }
}

In the previous code, we have not provided TaskExecutor as a bean, so Spring will use a default SimpleAsyncTaskExecutor implicitly.

The @Async annotation

Once asynchronous processing is enabled, then the methods that are annotated with...