@ExceptionHandler in controllers in Spring Boot - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to handle exceptions in a Spring Boot controller method.

Spring Boot

public class MyController {
    @[1]
    public ResponseEntity<String> handleException(Exception ex) {
        return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body("Error occurred");
    }
}

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

ARequestMapping

BPostMapping

CGetMapping

DExceptionHandler

Attempts:

3 left

💡 Hint

Common Mistakes

Using @GetMapping or @PostMapping instead of @ExceptionHandler

Forgetting to annotate the method

The @ExceptionHandler annotation is used to define a method that handles exceptions thrown by controller methods.

2fill in blank

medium

Complete the code to specify which exception type the handler method should catch.

Spring Boot

@ExceptionHandler([1].class)
public ResponseEntity<String> handleNotFound(Exception ex) {
    return ResponseEntity.status(HttpStatus.NOT_FOUND).body("Resource not found");
}

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AResourceNotFoundException

BRuntimeException

CNullPointerException

DIOException

Attempts:

3 left

💡 Hint

Common Mistakes

Using a general exception like RuntimeException instead of a specific one

Not specifying the exception class

You specify the exception class inside @ExceptionHandler to catch that specific exception type.

3fill in blank

hard

Fix the error in the exception handler method signature to correctly handle exceptions.

Spring Boot

@ExceptionHandler(ResourceNotFoundException.class)
public ResponseEntity<String> handleException([1] ex) {
    return ResponseEntity.status(HttpStatus.NOT_FOUND).body(ex.getMessage());
}

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AString

BException

CResourceNotFoundException

DHttpServletRequest

Attempts:

3 left

💡 Hint

Common Mistakes

Using a generic Exception type when a specific exception is declared

Using unrelated types like String or HttpServletRequest

The method parameter should be the same exception type declared in @ExceptionHandler to access its specific methods.

4fill in blank

hard

Fill both blanks to create a global exception handler class with proper annotations.

Spring Boot

@[1]
public class GlobalExceptionHandler {
    @[2]
    public ResponseEntity<String> handleAllExceptions(Exception ex) {
        return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body("Server error");
    }
}

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AControllerAdvice

BRestController

CExceptionHandler

DService

Attempts:

3 left

💡 Hint

Common Mistakes

Using @RestController instead of @ControllerAdvice for global handling

Missing @ExceptionHandler on the method

@ControllerAdvice marks the class as a global exception handler, and @ExceptionHandler marks the method to handle exceptions.

5fill in blank

hard

Fill all three blanks to handle a specific exception and return a custom message with status.

Spring Boot

@ExceptionHandler([1].class)
public ResponseEntity<String> handleCustomException([2] ex) {
    return ResponseEntity.status([3]).body("Custom error: " + ex.getMessage());
}

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ACustomException

CHttpStatus.BAD_REQUEST

DHttpStatus.NOT_FOUND

Attempts:

3 left

💡 Hint

Common Mistakes

Mismatching exception class and parameter type

Using wrong HTTP status codes

The method handles CustomException and returns a 400 Bad Request status with a custom message.