Nested DTOs in Spring Boot - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a nested DTO class inside the main DTO.

Spring Boot

public class UserDTO {
    private String name;
    private AddressDTO [1];

    public static class AddressDTO {
        private String city;
        private String zipCode;
    }
}

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

AaddressDto

BaddressDTO

Caddress

DaddressData

Attempts:

3 left

💡 Hint

Common Mistakes

Using the class name as the field name without camelCase.

Using unrelated names that do not represent the nested DTO.

The field name for the nested DTO should be 'address' to represent the AddressDTO object inside UserDTO.

2fill in blank

medium

Complete the constructor to initialize the nested DTO field.

Spring Boot

public UserDTO(String name, AddressDTO [1]) {
    this.name = name;
    this.address = [1];
}

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

Aaddress

Baddr

CaddressDTO

Dlocation

Attempts:

3 left

💡 Hint

Common Mistakes

Using different names for the parameter and the field.

Forgetting to assign the parameter to the field.

The constructor parameter and assignment should use the same field name 'address' to initialize the nested DTO.

3fill in blank

hard

Fix the error in the getter method for the nested DTO field.

Spring Boot

public AddressDTO [1]() {
    return address;
}

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

Aaddress

BgetAddress

CfetchAddress

DretrieveAddress

Attempts:

3 left

💡 Hint

Common Mistakes

Naming the getter method the same as the field.

Using non-standard prefixes like 'fetch' or 'retrieve'.

The getter method for a field named 'address' should be named 'getAddress' following Java bean conventions.

4fill in blank

hard

Fill both blanks to create a nested DTO with Lombok annotations for getters and setters.

Spring Boot

@Data
public class UserDTO {
    private String name;
    private [1] [2];

    @Data
    public static class AddressDTO {
        private String city;
        private String zipCode;
    }
}

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

AAddressDTO

Baddress

CString

Dcity

Attempts:

3 left

💡 Hint

Common Mistakes

Using primitive types instead of the nested DTO type.

Using incorrect field names that do not match the nested DTO.

The field type is 'AddressDTO' and the field name is 'address' to represent the nested DTO with Lombok @Data annotation.

5fill in blank

hard

Fill all three blanks to map nested DTO fields in a Spring Boot controller method.

Spring Boot

@PostMapping("/user")
public ResponseEntity<String> createUser(@RequestBody UserDTO [1]) {
    String city = [2].get[3]().getCity();
    // process city
    return ResponseEntity.ok("User from " + city);
}

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

AuserDTO

BAddress

CAddressDTO

Attempts:

3 left

💡 Hint

Common Mistakes

Using inconsistent parameter names.

Incorrect getter method names for nested DTO.

The method parameter is 'userDTO', then we call 'userDTO.getAddress()' to access the nested DTO and get the city.