@Around advice for full control in Spring Boot - Performance & Optimization

Performance: @Around advice for full control

MEDIUM IMPACT

This affects the runtime execution speed and responsiveness of Spring Boot applications by intercepting method calls.

Controlling method execution with @Around advice

Spring Boot

@Around("execution(* com.example..*(..))")
public Object lightweightAdvice(ProceedingJoinPoint pjp) throws Throwable {
  // minimal pre-processing
  Object result = pjp.proceed();
  // minimal post-processing
  return result;
}

Minimal logic avoids blocking and keeps method interception fast, preserving app responsiveness.

📈 Performance GainReduces overhead to near zero, avoiding added latency per method call.

Controlling method execution with @Around advice

Spring Boot

@Around("execution(* com.example..*(..))")
public Object heavyAdvice(ProceedingJoinPoint pjp) throws Throwable {
  // heavy processing before
  Thread.sleep(100); // simulate delay
  Object result = pjp.proceed();
  // heavy processing after
  Thread.sleep(100); // simulate delay
  return result;
}

Heavy processing or blocking calls inside @Around advice delay every intercepted method call, increasing response time.

📉 Performance CostAdds 200ms delay per method call intercepted, increasing latency and reducing throughput.

Performance Comparison

Pattern	Method Interception Overhead	Thread Blocking	Latency Impact	Verdict
Heavy processing in @Around advice	High (every method call)	Yes (Thread.sleep)	High latency per call	[X] Bad
Lightweight @Around advice	Low (minimal code)	No	Minimal latency	[OK] Good

Rendering Pipeline

The @Around advice intercepts method calls before and after execution, adding extra steps in the call stack.

→Method Invocation

→Application Thread Execution

⚠️ BottleneckHeavy or blocking code inside advice increases method execution time and thread blocking.

Optimization Tips

1Avoid heavy or blocking code inside @Around advice to prevent slowing method calls.

2Use @Around advice sparingly and only on necessary methods to reduce overhead.

3Profile advice execution time with Java Flight Recorder to detect performance bottlenecks.

Performance Quiz - 3 Questions

What is the main performance risk of using heavy processing inside @Around advice?

A It improves application startup time.

B It reduces bundle size.

C It increases method call latency and blocks threads.

D It decreases memory usage.

DevTools: Spring Boot Actuator + Java Flight Recorder

How to check: Enable Actuator metrics and record method execution times with Java Flight Recorder to profile advice overhead.

What to look for: Look for increased method execution times and thread blocking during advice execution.

Practice

1. What is the main purpose of using @Around advice in Spring AOP?

easy

A. To run code before and after a method, controlling its execution fully

B. To only run code after a method finishes

C. To replace the method with a new implementation without calling the original

D. To log method parameters without affecting execution

Solution

1. Step 1: Understand the role of @Around advice

   @Around advice wraps a method, allowing code to run before and after the method execution.

2. Step 2: Compare options with this behavior

   Only To run code before and after a method, controlling its execution fully describes full control before and after the method, matching @Around's purpose.

3. Final Answer:

   To run code before and after a method, controlling its execution fully -> Option A

4. Quick Check:

   @Around advice = full control before and after method [OK]

Hint: Remember @Around wraps method execution fully [OK]

Common Mistakes:

• Thinking @Around only runs after method
• Confusing @Around with @After or @Before
• Forgetting @Around can modify inputs and outputs

2. Which of the following is the correct way to proceed with the original method inside an @Around advice method?

easy

A. return joinPoint.proceed();

B. joinPoint.execute();

C. proceed(joinPoint);

D. joinPoint.run();

Solution

1. Step 1: Recall the method to call original execution

   In @Around advice, the original method is executed by calling joinPoint.proceed().

2. Step 2: Match the correct syntax

   Only return joinPoint.proceed(); uses the correct method name and syntax to proceed.

3. Final Answer:

   return joinPoint.proceed(); -> Option A

4. Quick Check:

   Call original method with joinPoint.proceed() [OK]

Hint: Use joinPoint.proceed() to run original method [OK]

Common Mistakes:

• Using incorrect method names like execute() or run()
• Forgetting to return the result of proceed()
• Calling proceed() without parentheses

3. Given the following @Around advice code, what will be printed when someMethod() returns "Hello"?

@Around("execution(* someMethod())")
public Object aroundAdvice(ProceedingJoinPoint joinPoint) throws Throwable {
    System.out.println("Before");
    Object result = joinPoint.proceed();
    System.out.println("After");
    return result + " World";
}

medium

A. Before
Hello
After
World

B. Hello
Before
After
World

C. Before
After
Hello

D. Before
After
Hello World

Solution

1. Step 1: Trace the advice execution order

   The advice prints "Before", then calls the original method which returns "Hello", then prints "After".

2. Step 2: Understand the returned value

   The advice returns the original result plus " World", so the final returned string is "Hello World".

3. Final Answer:

   Before After Hello World -> Option D

4. Quick Check:

   Prints before and after, returns modified result [OK]

Hint: Remember @Around runs code before and after proceed() [OK]

Common Mistakes:

• Assuming original method output is unchanged
• Mixing print order with return value
• Forgetting to add " World" to result

4. Identify the error in this @Around advice method:

@Around("execution(* someMethod())")
public Object aroundAdvice(ProceedingJoinPoint joinPoint) {
    System.out.println("Start");
    Object result = joinPoint.proceed();
    System.out.println("End");
    return result;
}

medium

A. Incorrect annotation syntax

B. Missing throws Throwable declaration in method signature

C. Should call joinPoint.execute() instead of proceed()

D. Cannot return Object type from advice

Solution

1. Step 1: Check method signature requirements

   joinPoint.proceed() throws Throwable, so the advice method must declare throws Throwable or handle it.

2. Step 2: Identify missing throws declaration

   The method lacks "throws Throwable", causing a compile error.

3. Final Answer:

   Missing throws Throwable declaration in method signature -> Option B

4. Quick Check:

   proceed() throws Throwable, must declare it [OK]

Hint: Add throws Throwable when calling joinPoint.proceed() [OK]

Common Mistakes:

• Ignoring checked exceptions from proceed()
• Using wrong method name instead of proceed()
• Not matching annotation syntax

5. You want to create an @Around advice that modifies the input argument of a method before execution and changes the returned result after execution. Which approach correctly achieves this?

hard

A. Modify the method parameters directly without using proceed, then return null

B. Call joinPoint.proceed() without arguments, then ignore the result and return a new value

C. Modify the argument array via joinPoint.getArgs(), then call joinPoint.proceed(modifiedArgs), and finally modify the returned result before returning

D. Use joinPoint.proceed() and modify the result, but cannot change input arguments

Solution

1. Step 1: Understand argument modification in @Around advice

   You can get and modify method arguments using joinPoint.getArgs() and pass them to proceed() to change inputs.

2. Step 2: Modify the returned result after proceed()

   After calling proceed with modified arguments, you can change the returned value before returning it.

3. Final Answer:

   Modify the argument array via joinPoint.getArgs(), then call joinPoint.proceed(modifiedArgs), and finally modify the returned result before returning -> Option C

4. Quick Check:

   Change inputs with proceed(args), then modify output [OK]

Hint: Use proceed(modifiedArgs) to change inputs, then modify output [OK]

Common Mistakes:

• Calling proceed() without modified arguments when inputs need change
• Trying to change parameters directly without proceed()
• Ignoring returned result modification