Request DTO for input in Spring Boot - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a simple Request DTO class with a private field and its getter.

Spring Boot

public class UserRequestDTO {
    private String [1];

    public String getUsername() {
        return username;
    }
}

Drag options to blanks, or click blank then click option'

Aname

Busername

CuserName

Duser

Attempts:

3 left

💡 Hint

Common Mistakes

Using a field name that does not match the getter method name.

Using uppercase letters at the start of the field name.

The field name must match the getter method name. Here, the getter is getUsername(), so the field should be username.

2fill in blank

medium

Complete the code to add a setter method for the field in the Request DTO.

Spring Boot

public void [1](String username) {
    this.username = username;
}

Drag options to blanks, or click blank then click option'

AupdateUsername

BsetUser

CgetUsername

DsetUsername

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'get' instead of 'set' in the method name.

Using a method name that does not match the field name.

Setter methods in Java follow the pattern setFieldName. Here, the field is username, so the setter is setUsername.

3fill in blank

hard

Fix the error in the annotation to make this class a valid Request DTO in Spring Boot.

Spring Boot

@[1]
public class UserRequestDTO {
    private String username;

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }
}

Drag options to blanks, or click blank then click option'

AData

BEntity

CRequestBody

DRestController

Attempts:

3 left

💡 Hint

Common Mistakes

Using @Entity which is for database entities.

Using @RestController which is for controllers.

Using @RequestBody which is for method parameters.

The @Data annotation from Lombok generates getters and setters automatically, making the DTO concise and valid.

4fill in blank

hard

Fill both blanks to create a Request DTO with validation annotations for a non-empty username.

Spring Boot

import jakarta.validation.constraints.[1];

public class UserRequestDTO {
    @[2](message = "Username cannot be empty")
    private String username;

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }
}

Drag options to blanks, or click blank then click option'

ANotBlank

BNotNull

CSize

DEmail

Attempts:

3 left

💡 Hint

Common Mistakes

Using @NotNull which allows empty strings.

Using @Email which is for email format validation.

The @NotBlank annotation ensures the username is not null and not empty after trimming spaces.

5fill in blank

hard

Fill all three blanks to create a Request DTO with username and age fields, including validation for non-empty username and minimum age 18.

Spring Boot

import jakarta.validation.constraints.[1];
import jakarta.validation.constraints.[2];

public class UserRequestDTO {
    @[3](message = "Username cannot be empty")
    private String username;

    @Min(18)
    private int age;

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }
}

Drag options to blanks, or click blank then click option'

ANotBlank

BMin

CNotNull

DSize

Attempts:

3 left

💡 Hint

Common Mistakes

Importing @NotNull instead of @NotBlank for username.

Not importing @Min for age validation.

Import NotBlank for username validation and Min for age validation. The username field uses @NotBlank.