Error Handling with Spring Boot

Welcome to our guide on implementing robust error handling in a Spring Boot application. We’ll leverage Spring Boot’s capabilities to create a system that effectively captures, processes, and presents errors.

1. Overview

This guide outlines the implementation of a robust error handling system in a Spring Boot application. By leveraging Spring Boot’s features, we’ll create mechanisms to capture, process, and present errors effectively.

2. Prerequisites

Before we dive into the implementation, make sure you have the necessary prerequisites installed on your system:

Java Development Kit (JDK): Ensure you have JDK version 17 or higher installed.
Maven: You’ll need Maven as a build tool for managing dependencies and building the project.

3. Maven Dependencies

Add the required dependencies to your pom.xml:

<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-web</artifactId>
</dependency>

<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-devtools</artifactId>
  <scope>runtime</scope>
  <optional>true</optional>
</dependency>
<dependency>
  <groupId>org.projectlombok</groupId>
  <artifactId>lombok</artifactId>
  <optional>true</optional>
</dependency>

4. Configure Exception Handler

4.1. ErrorResponse

@Getter
@Setter
@AllArgsConstructor
public class ErrorResponse {
    private String error;
    private String message;
    private int errorCode;
}

4.2. GlobalExceptionHandler

@RestControllerAdvice
public class GlobalExceptionHandler {

    private static final Logger logger = LoggerFactory.getLogger(GlobalExceptionHandler.class);

    @ExceptionHandler(IllegalArgumentException.class)
    @ResponseStatus(HttpStatus.BAD_REQUEST)
    public ErrorResponse handleIllegalArgumentRequestException(IllegalArgumentException ex) {
        logger.error("Call handleIllegalArgumentRequestException: {}", ex.getMessage());
        return new ErrorResponse(HttpStatus.BAD_REQUEST.getReasonPhrase(), ex.getMessage(),
                HttpStatus.BAD_REQUEST.value());
    }

    @ExceptionHandler(Exception.class)
    @ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
    public ErrorResponse handleGenericException(Exception ex) {
        logger.error("Call handleGenericException: {}", ex.getMessage());
        return new ErrorResponse(HttpStatus.INTERNAL_SERVER_ERROR.getReasonPhrase(), ex.getMessage(),
                HttpStatus.INTERNAL_SERVER_ERROR.value());
    }
}

5. The Controller

5.1. HomeController

@RestController
public class HomeController {

    private static final Logger logger = LoggerFactory.getLogger(GlobalExceptionHandler.class);

    @GetMapping("/")
    public String retResponse(@RequestParam(required = false) String name) {
        logger.info("Call retResponse");

        if (name == null || name.isBlank()) {
            throw new IllegalArgumentException("Please provide your name");
        }
        return String.format("Hey %s, you got a response", name);
    }
}

6. Run The Application

Finally, we’ll run the Spring Boot application using Maven.

mvn clean spring-boot:run

7. Check If The API Is Working

curl http://localhost:8080?name=abhi -w "\n"

If you receive a 200 status code with the response body Hey abhi, you got a response, your API is functioning correctly.

To test without required param:

curl http://localhost:8080 -w "\n"

You will get an Error Message now, as you didn’t provide the required param, which is desired.

{"error":"Bad Request","message":"Please provide your name","errorCode":400}

Here is the Github Repo for this Article!

Tags: spring-boot java