How to Call an Async Method from Another Async Method in Spring

How can I properly call an asynchronous method within another asynchronous method in a Spring application?

@Async
public CompletableFuture<String> firstAsyncMethod() {
    // Simulate delay
    Thread.sleep(1000);
    return CompletableFuture.completedFuture("Result from first async method");
}

@Async
public CompletableFuture<String> secondAsyncMethod() {
    return firstAsyncMethod(); // Calling first async method
}

In a Spring application, you can easily call an asynchronous method from another asynchronous method using `@Async`. However, special care must be taken regarding the context and threading model of Spring's async functionality.

@Async
public CompletableFuture<String> performAsyncOperation() {
    // Simulate a long-running task
    Thread.sleep(2000);
    return CompletableFuture.completedFuture("Async operation completed");
}

@Async
public CompletableFuture<String> executeAsync() {
    return performAsyncOperation(); // Calling another async method
}

Causes

• Incorrect `@Async` configuration
• Not using `CompletableFuture` properly
• Lack of proper threading context when calling async methods

Solutions

• Ensure that the `@Async` annotation is used properly with Spring's proxy-based approach.
• Return a `CompletableFuture` from each async method to allow chaining and error handling effectively.
• Make sure that the class implementing these methods is managed by Spring (annotated with `@Service`, `@Component`, etc.) to leverage Spring's proxying for async calls.

Mistake: Not returning `CompletableFuture` from async methods.

Solution: Always return `CompletableFuture` to allow for proper chaining of async calls and results.

Mistake: Calling async methods from the same class instance (e.g., `this`) instead of a Spring-managed bean.

Solution: Invoke async methods via another Spring-managed bean to ensure they are executed asynchronously.