Response DTO for output in Spring Boot - Mini Project: Build & Apply

Response DTO for output

📖 Scenario: You are building a simple Spring Boot application that returns user information as a response. To keep your code clean and organized, you want to create a Response DTO (Data Transfer Object) that will hold the user data sent back to the client.

🎯 Goal: Create a Response DTO class in Spring Boot that holds user data fields and use it to return user information in a structured way.

📋 What You'll Learn

Create a Java class named UserResponseDto with private fields: id (Long), name (String), and email (String).

Add public getters and setters for all fields.

Add a constructor that accepts all fields as parameters.

Use the DTO class to prepare a response object.

💡 Why This Matters

🌍 Real World

Response DTOs are used in real applications to send only the necessary data to clients in a clean and organized way, improving API design and maintainability.

💼 Career

Understanding how to create and use Response DTOs is essential for backend developers working with Spring Boot to build RESTful APIs.

1

Create the Response DTO class

Create a public Java class named UserResponseDto with private fields id of type Long, name of type String, and email of type String.

Spring Boot

public class UserResponseDto {
    // Your code here
}

Need a hint?

Define the class and declare the fields as private variables inside it.

2

Add constructor and getters/setters

Add a public constructor to UserResponseDto that accepts Long id, String name, and String email as parameters and assigns them to the fields. Also add public getter and setter methods for each field.

Spring Boot

public class UserResponseDto {
    private Long id;
    private String name;
    private String email;

    // Your code here
}

Need a hint?

Write a constructor that sets all fields. Then add getter and setter methods for each field.

3

Create a sample UserResponseDto object

In a separate class or method, create a new UserResponseDto object named response using the constructor with id as 1L, name as "Alice", and email as "[e-mail]".

Spring Boot

public class UserResponseDto {
    // existing code
}

// Your code here to create UserResponseDto object

Need a hint?

Create a new instance of UserResponseDto using the constructor with the exact values.

4

Use Response DTO in a Spring Boot controller method

Write a Spring Boot controller method named getUser that returns the UserResponseDto object response. The method should be annotated with @GetMapping("/user") and return type UserResponseDto.

Spring Boot

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

@RestController
public class UserController {

    // Your code here
}

Need a hint?

Create a controller class with a method annotated with @GetMapping("/user") that returns the response object.