Problem Details for standard error format in Spring Boot - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a Problem Details response with a title.

Spring Boot

ProblemDetail problem = ProblemDetail.forStatus(HttpStatus.BAD_REQUEST);
problem.set[1]("Invalid input");

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

AsetError

BsetMessage

CsetTitle

DsetDescription

Attempts:

3 left

💡 Hint

Common Mistakes

Using setMessage instead of setTitle

Trying to set description instead of title

The setTitle method sets the title of the problem detail, which describes the error briefly.

2fill in blank

medium

Complete the code to add a detailed error message to the ProblemDetail.

Spring Boot

problem.set[1]("The provided ID is not valid.");

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

AsetInstance

BsetTitle

CsetStatus

DsetDetail

Attempts:

3 left

💡 Hint

Common Mistakes

Using setTitle instead of setDetail

Trying to set status instead of detail

The setDetail method adds a detailed explanation about the error.

3fill in blank

hard

Fix the error in setting the HTTP status code for the ProblemDetail.

Spring Boot

problem.setStatus(HttpStatus.[1]);

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

ABAD_REQUEST.value()

BBAD_REQUEST

C400

DNOT_FOUND

Attempts:

3 left

💡 Hint

Common Mistakes

Passing an integer status code instead of HttpStatus enum

Calling .value() method inside setStatus

The setStatus method expects an HttpStatus enum value, not an int or method call.

4fill in blank

hard

Fill both blanks to create a ProblemDetail with a custom type URI and instance URI.

Spring Boot

problem.set[1](URI.create("https://example.com/probs/invalid-input"));
problem.set[2](URI.create("/orders/1234"));

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

AsetType

BsetTitle

CsetInstance

DsetDetail

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up setTitle and setType

Using setDetail instead of setInstance

setType sets a URI identifying the error type.
setInstance sets a URI identifying the specific occurrence of the problem.

5fill in blank

hard

Fill all three blanks to create a ProblemDetail with title, detail, and status.

Spring Boot

problem.set[1]("Unauthorized access");
problem.set[2]("You must log in to access this resource.");
problem.set[3](HttpStatus.UNAUTHORIZED);

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

AsetTitle

BsetDetail

CsetStatus

DsetInstance

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing setInstance with setStatus

Using setDetail for the title

setTitle sets the short error title.
setDetail sets the detailed message.
setStatus sets the HTTP status code.

Practice

1. What is the main purpose of using Problem Details in Spring Boot APIs?

easy

A. To standardize error messages for better clarity and consistency

B. To speed up API response times

C. To encrypt API responses for security

D. To generate API documentation automatically

Solution

1. Step 1: Understand the role of Problem Details

   Problem Details format is designed to provide a consistent structure for error messages in APIs.

2. Step 2: Identify the main benefit

   This standardization helps clients understand errors clearly and handle them properly.

3. Final Answer:

   To standardize error messages for better clarity and consistency -> Option A

4. Quick Check:

   Standard error format = clarity [OK]

Hint: Problem Details = clear, consistent error messages [OK]

Common Mistakes:

• Thinking it improves speed
• Confusing with security features
• Assuming it auto-generates docs

2. Which of the following fields is NOT part of the standard Problem Details JSON format?

easy

A. type

B. title

C. timestamp

D. status

Solution

1. Step 1: Recall standard Problem Details fields

   The standard fields include type, title, status, detail, and instance.

2. Step 2: Identify the incorrect field

   Timestamp is not part of the official Problem Details specification.

3. Final Answer:

   timestamp -> Option C

4. Quick Check:

   Standard fields exclude timestamp [OK]

Hint: Remember standard fields: type, title, status, detail, instance [OK]

Common Mistakes:

• Confusing timestamp with instance
• Assuming all error info fields are standard
• Mixing with custom fields

3. Given this Spring Boot controller snippet, what will be the HTTP status code in the Problem Details response when ResourceNotFoundException is thrown?

@RestController
public class MyController {
  @GetMapping("/item/{id}")
  public Item getItem(@PathVariable String id) {
    throw new ResourceNotFoundException("Item not found");
  }
}

medium

A. 404 Not Found

B. 200 OK

C. 500 Internal Server Error

D. 400 Bad Request

Solution

1. Step 1: Understand exception mapping in Spring Boot

   ResourceNotFoundException typically maps to HTTP 404 status to indicate missing resource.

2. Step 2: Confirm standard error status for not found

   Spring Boot's default error handling returns 404 for resource not found exceptions.

3. Final Answer:

   404 Not Found -> Option A

4. Quick Check:

   Resource missing = 404 [OK]

Hint: Resource not found usually means 404 status [OK]

Common Mistakes:

• Assuming 200 OK on exception
• Confusing 400 with 404
• Thinking all exceptions return 500

4. You wrote a custom exception handler to return Problem Details but the API returns a plain error message instead. What is the most likely cause?

medium

A. The exception class does not extend RuntimeException

B. The controller method is not annotated with @GetMapping

C. The application.properties file is missing

D. The handler method is missing @ExceptionHandler annotation

Solution

1. Step 1: Check exception handler setup

   Custom handlers must use @ExceptionHandler to catch exceptions and format responses.

2. Step 2: Identify missing annotation impact

   Without @ExceptionHandler, Spring Boot won't invoke the handler, so default error response is sent.

3. Final Answer:

   The handler method is missing @ExceptionHandler annotation -> Option D

4. Quick Check:

   @ExceptionHandler missing = no custom error [OK]

Hint: Always add @ExceptionHandler to custom error methods [OK]

Common Mistakes:

• Thinking controller mapping affects exception handling
• Assuming properties file controls error format
• Believing exception must extend RuntimeException

5. How can you customize the type field in a Problem Details response for a specific exception in Spring Boot?

hard

A. Override the toString() method of the exception class

B. Create a @ControllerAdvice with @ExceptionHandler and build a ProblemDetail with custom type URI

C. Set a property in application.properties named error.type.custom

D. Add a @RequestMapping with produces = "application/problem+json" on the controller

Solution

1. Step 1: Use @ControllerAdvice and @ExceptionHandler

   To customize error details, define a global handler that catches the exception.

2. Step 2: Build ProblemDetail with custom type URI

   Inside the handler, create a ProblemDetail object and set the type field to a custom URI describing the error.

3. Final Answer:

   Create a @ControllerAdvice with @ExceptionHandler and build a ProblemDetail with custom type URI -> Option B

4. Quick Check:

   Custom type = @ExceptionHandler + ProblemDetail [OK]

Hint: Use @ExceptionHandler to customize ProblemDetail fields [OK]

Common Mistakes:

• Trying to override toString() for error format
• Expecting properties file to set type field
• Using @RequestMapping alone to customize error