@RestController annotation in Spring Boot - Mini Project: Build & Apply

Using the @RestController Annotation in Spring Boot

📖 Scenario: You are building a simple web service that responds with greeting messages. This service will use Spring Boot to create a REST API endpoint.

🎯 Goal: Create a Spring Boot REST controller using the @RestController annotation that returns a greeting message when accessed via HTTP GET.

📋 What You'll Learn

Create a Spring Boot application class

Create a controller class annotated with @RestController

Add a method that handles GET requests at path /greet

Return a plain text greeting message from the method

💡 Why This Matters

🌍 Real World

REST controllers are used to build web services that communicate over HTTP, commonly used in web and mobile apps.

💼 Career

Understanding @RestController is essential for backend developers working with Spring Boot to create APIs.

1

Create the Spring Boot application class

Create a class called GreetingApplication annotated with @SpringBootApplication and add the main method that runs SpringApplication.run(GreetingApplication.class, args).

Spring Boot

// Create the GreetingApplication class with @SpringBootApplication and main method
// Your code here

Need a hint?

The main class needs the @SpringBootApplication annotation and a main method to start the app.

2

Create the REST controller class

Create a class called GreetingController and annotate it with @RestController.

Spring Boot

import org.springframework.web.bind.annotation.RestController;

// Create the GreetingController class annotated with @RestController
// Your code here

Need a hint?

The controller class must have the @RestController annotation above the class declaration.

3

Add a GET method to return a greeting

Inside the GreetingController class, add a method called greet annotated with @GetMapping("/greet") that returns the string "Hello, Spring Boot!".

Spring Boot

import org.springframework.web.bind.annotation.GetMapping;

// Add a method greet() annotated with @GetMapping("/greet") that returns "Hello, Spring Boot!"
// Your code here

Need a hint?

The method should be public, return a String, and have the @GetMapping("/greet") annotation.

4

Complete the REST controller setup

Ensure the GreetingController class imports org.springframework.web.bind.annotation.GetMapping and that the class and method are properly structured to serve the greeting at /greet.

Spring Boot

// Verify imports and class structure are complete
// Your code here

Need a hint?

Make sure all necessary imports are present and the class and method annotations are correct.