@Before advice in Spring Boot - Performance & Optimization

Performance: @Before advice

MEDIUM IMPACT

@Before advice affects the execution time before the main method runs, impacting interaction responsiveness and overall request handling speed.

Running code before a method executes to add logging or validation

Spring Boot

@Before("execution(* com.example.service.*.*(..))")
public void lightweightBeforeAdvice() {
  // simple logging or quick validation
  logger.info("Method called");
}

Runs quickly without blocking main method, keeping request handling fast and responsive.

📈 Performance GainNon-blocking, adds negligible delay, improves INP

Running code before a method executes to add logging or validation

Spring Boot

@Before("execution(* com.example.service.*.*(..))")
public void heavyBeforeAdvice() throws InterruptedException {
  // heavy computation or blocking IO
  Thread.sleep(1000);
  // complex database calls
}

This advice blocks the main method execution by performing heavy or blocking operations, causing slow response times.

📉 Performance CostBlocks main thread for 1000ms per call, increasing INP and slowing user experience

Performance Comparison

Pattern	DOM Operations	Reflows	Paint Cost	Verdict
Heavy blocking @Before advice	N/A	N/A	N/A	[X] Bad
Lightweight logging @Before advice	N/A	N/A	N/A	[OK] Good

Rendering Pipeline

@Before advice runs before the target method, adding overhead to request processing before response generation.

→Application Logic Execution

→Request Handling

⚠️ BottleneckBlocking or heavy operations inside @Before advice delay method execution and response time.

Core Web Vital Affected

INP

@Before advice affects the execution time before the main method runs, impacting interaction responsiveness and overall request handling speed.

Optimization Tips

1Avoid heavy or blocking operations inside @Before advice.

2Use @Before advice only for quick tasks like logging or simple validation.

3Profile advice execution time to detect and fix performance bottlenecks.

Performance Quiz - 3 Questions

What is the main performance risk of using heavy operations inside @Before advice?

A It blocks the main method execution, increasing response time

B It reduces bundle size

C It improves page rendering speed

D It decreases network latency

DevTools: Spring Boot Actuator / Application Profiler

How to check: Use profiling tools or actuator metrics to measure method execution time including advice overhead; check logs for delays.

What to look for: Look for increased method execution time or blocking caused by @Before advice indicating performance issues.