AOP for logging in Spring Boot - Mini Project: Build & Apply

AOP for logging

📖 Scenario: You are building a Spring Boot application where you want to log method calls automatically without adding logging code inside each method. This helps keep your code clean and makes it easier to track what methods are called and when.

🎯 Goal: Create an Aspect using Spring AOP that logs the start and end of method executions in a service class.

📋 What You'll Learn

Create a service class called MyService with a method performTask that returns a string.

Create an Aspect class called LoggingAspect that logs before and after the performTask method runs.

Use Spring AOP annotations like @Aspect, @Before, and @After.

Print log messages to the console indicating when the method starts and ends.

💡 Why This Matters

🌍 Real World

Logging method calls automatically helps developers track application behavior without cluttering business logic with print statements.

💼 Career

Understanding AOP and logging is important for building maintainable Spring Boot applications and is a common task in backend development roles.

1

Create the service class

Create a Spring service class called MyService with a public method performTask that returns the string "Task Completed".

Spring Boot

# Create the MyService class with performTask method
// Your code here

Need a hint?

Use @Service annotation on the class and define the method exactly as public String performTask().

2

Create the logging aspect class

Create an Aspect class called LoggingAspect annotated with @Aspect and @Component. Define a pointcut that matches the execution of performTask method in MyService.

Spring Boot

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

// Create LoggingAspect class with @Aspect and @Component annotations
// Define a pointcut for performTask method
// Your code here

Need a hint?

Use @Pointcut with the expression execution(* MyService.performTask(..)) to match the method.

3

Add logging before and after method execution

In the LoggingAspect class, add a @Before advice method that prints "Starting performTask" and an @After advice method that prints "Finished performTask". Both advices should use the performTaskPointcut() pointcut.

Spring Boot

import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.After;

// Add @Before advice to print "Starting performTask"
// Add @After advice to print "Finished performTask"
// Your code here

Need a hint?

Use @Before and @After annotations on methods that print the required messages.

4

Run and verify logging output

Write a main method in a Spring Boot application class that gets the MyService bean from the application context and calls performTask(). Run the application and verify the console output shows Starting performTask, then Finished performTask, and finally the returned string Task Completed.

Spring Boot

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

@SpringBootApplication
public class Application {
    public static void main(String[] args) {
        // Get Spring context and call performTask
        // Your code here
    }
}

Need a hint?

Use SpringApplication.run to start the app, get MyService bean, call performTask(), and print the result.