@Before advice in Spring Boot - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the @Before advice in Spring AOP?

The @Before advice runs a method before the target method executes. It is used to perform actions like logging, security checks, or setting up resources before the main method runs.

beginner

How do you declare a @Before advice in Spring Boot?

You create a method annotated with @Before and provide a pointcut expression that matches the methods where you want the advice to run.

@Before("execution(* com.example.service.*.*(..))")
public void beforeAdvice() {
  // code to run before target method
}

intermediate

What is a pointcut expression in the context of @Before advice?

A pointcut expression defines which methods the advice should apply to. It uses patterns to match method names, packages, or classes.

intermediate

Can @Before advice modify the return value of the target method?

No, @Before advice runs before the method and cannot change the return value. To modify return values, use @Around advice.

beginner

Give a real-life example where @Before advice is useful.

Before a bank transaction method runs, @Before advice can check if the user is authenticated and log the transaction attempt.

What does @Before advice do in Spring AOP?

A Modifies the return value of the target method

B Runs code after the target method executes

C Runs code before the target method executes

D Handles exceptions thrown by the target method

@Before advice runs before the target method starts, allowing pre-processing.

Which annotation is used to declare a method as a @Before advice?

A @Before

B @After

C @Around

D @Pointcut

@Before marks a method to run before matched methods.

Can @Before advice stop the execution of the target method?

A Yes, by throwing an exception

B No, it always lets the method run

C Yes, by returning false

D No, it runs after the method

@Before advice can throw exceptions to prevent the target method from running.

What is a pointcut expression used for in @Before advice?

A To define when the advice runs

B To define which methods the advice applies to

C To modify method arguments

D To log method return values

Pointcut expressions select the methods where advice applies.

Which advice type allows modifying the return value of a method?

A @Before

B @AfterThrowing

C @After

D @Around

@Around advice can control method execution and modify return values.

Explain how @Before advice works in Spring Boot and give an example use case.

Think about what you want to do before a method runs.

Describe the difference between @Before advice and @Around advice.

Consider when each advice runs and what it can do.