Why AOP matters in Spring Boot - See It in Action

Why AOP matters

📖 Scenario: You are building a simple Spring Boot application that logs method execution times to improve performance monitoring.

🎯 Goal: Create a Spring Boot project that uses Aspect-Oriented Programming (AOP) to log the execution time of a service method without changing the method's code.

📋 What You'll Learn

Create a service class with a method that simulates work by sleeping for 1 second

Create a configuration variable to enable AOP logging

Create an aspect class that logs the execution time of the service method

Apply the aspect to the service method and complete the Spring Boot application setup

💡 Why This Matters

🌍 Real World

AOP helps add features like logging, security, and transactions without changing the main business code, making maintenance easier.

💼 Career

Understanding AOP is important for Java developers working with Spring Boot to write clean, modular, and maintainable code.

1

Create the service class

Create a Spring service class called WorkService with a method performTask() that sleeps for 1000 milliseconds to simulate work.

Spring Boot

import org.springframework.stereotype.Service;

// Your code here

Need a hint?

Use @Service annotation and a method that calls Thread.sleep(1000) inside a try-catch block.

2

Enable AOP logging configuration

Create a configuration class called AopConfig and add the @EnableAspectJAutoProxy annotation to enable AOP support in the Spring Boot application.

Spring Boot

import org.springframework.stereotype.Service;

@Service
public class WorkService {
    public void performTask() {
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
        }
    }
}

import org.springframework.context.annotation.Configuration;

// Add @EnableAspectJAutoProxy annotation here
// Your code here

Need a hint?

Use @Configuration and @EnableAspectJAutoProxy annotations on the AopConfig class.

3

Create the logging aspect

Create an aspect class called LoggingAspect with a method logExecutionTime() that uses @Around advice to log the execution time of performTask() method in WorkService.

Spring Boot

import org.springframework.stereotype.Service;

@Service
public class WorkService {
    public void performTask() {
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
        }
    }
}

import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.EnableAspectJAutoProxy;

@Configuration
@EnableAspectJAutoProxy
public class AopConfig {
}

import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.springframework.stereotype.Component;

// Your code here

Need a hint?

Use @Aspect and @Component annotations. Use @Around advice with the pointcut for performTask().

4

Complete the Spring Boot application

Create the main Spring Boot application class called Application with the @SpringBootApplication annotation and a main method that runs the application. Autowire WorkService and call performTask() inside the main method.

Spring Boot

import org.springframework.stereotype.Service;

@Service
public class WorkService {
    public void performTask() {
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
        }
    }
}

import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.EnableAspectJAutoProxy;

@Configuration
@EnableAspectJAutoProxy
public class AopConfig {
}

import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.springframework.stereotype.Component;

@Aspect
@Component
public class LoggingAspect {
    @Around("execution(* WorkService.performTask(..))")
    public Object logExecutionTime(ProceedingJoinPoint joinPoint) throws Throwable {
        long start = System.currentTimeMillis();
        Object proceed = joinPoint.proceed();
        long executionTime = System.currentTimeMillis() - start;
        System.out.println(joinPoint.getSignature() + " executed in " + executionTime + "ms");
        return proceed;
    }
}

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ApplicationContext;

// Your code here

Need a hint?

Use @SpringBootApplication on the main class. Use SpringApplication.run() to start. Get WorkService bean and call performTask().