Exception handling in async in Spring Boot - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the main challenge of exception handling in asynchronous methods in Spring Boot?

In asynchronous methods, exceptions do not propagate to the caller thread directly, so they must be handled differently, often by using callbacks or special handlers.

intermediate

How can you handle exceptions thrown in a method annotated with @Async in Spring Boot?

You can handle exceptions by returning a Future or CompletableFuture and checking for exceptions, or by implementing AsyncUncaughtExceptionHandler for void async methods.

intermediate

What is AsyncUncaughtExceptionHandler used for in Spring Boot?

AsyncUncaughtExceptionHandler handles exceptions thrown from @Async methods that return void, allowing you to define custom logic for uncaught exceptions.

advanced

How do you configure a custom AsyncUncaughtExceptionHandler in Spring Boot?

Implement AsyncConfigurer interface and override getAsyncUncaughtExceptionHandler() to return your custom handler, then enable async support with @EnableAsync.

intermediate

Why is it recommended to use CompletableFuture for exception handling in async methods?

CompletableFuture allows chaining callbacks and provides methods like exceptionally() to handle exceptions cleanly and asynchronously.

Which annotation is used to mark a method as asynchronous in Spring Boot?

A @Async

B @AsyncException

C @AsyncHandler

D @AsyncCatch

The @Async annotation marks a method to run asynchronously in Spring Boot.

What does AsyncUncaughtExceptionHandler handle?

A Exceptions from scheduled tasks

B Exceptions from async methods returning Future

C Exceptions from async void methods

D Exceptions from synchronous methods

AsyncUncaughtExceptionHandler handles exceptions thrown from async methods that return void.

How can you catch exceptions from an async method returning CompletableFuture?

A Using try-catch inside the async method only

B Using AsyncUncaughtExceptionHandler

C Using @ExceptionHandler annotation

D Using exceptionally() method on CompletableFuture

The exceptionally() method on CompletableFuture allows handling exceptions asynchronously.

Which interface should you implement to customize async exception handling globally?

A AsyncConfigurer

B AsyncExceptionHandler

C AsyncHandler

D AsyncExceptionListener

Implementing AsyncConfigurer allows you to provide a custom AsyncUncaughtExceptionHandler.

What happens if an exception is thrown in an async method returning void without a handler?

A The exception is propagated to the caller thread

B The exception is lost and logged by default

C The application crashes immediately

D The exception is automatically retried

Exceptions in async void methods without a handler are lost but logged by Spring's default behavior.

Explain how exception handling differs between async methods returning void and those returning CompletableFuture in Spring Boot.

Think about how exceptions are caught or lost depending on the return type.

Describe the steps to set up a custom global exception handler for asynchronous methods in Spring Boot.

Focus on configuration and enabling async support.