Spring Boot REST服务异常处理

使用Spring Boot开发REST服务时，异常处理是一个非常重要的方面。在实际开发中，我们经常会遇到各种可能导致服务出现异常的情况，如参数校验失败、资源不存在、权限不足等。为了保证系统的稳定性和可靠性，我们需要对这些异常进行统一处理，并返回合适的错误信息给客户端。

java
public class ResourceNotFoundException extends RuntimeException {
    public ResourceNotFoundException(String message) {
        super(message);
    }
}

java
@RestController
public class UserController {
    @GetMapping("/users/{id}")
    public User getUser(@PathVariable Long id) {
        User user = userRepository.findById(id)
                .orElseThrow(() -> new ResourceNotFoundException("User not found with id: " + id));
        return user;
    }
}

java
@ControllerAdvice
public class GlobalExceptionHandler {
    @ExceptionHandler(ResourceNotFoundException.class)
    public ResponseEntity handleResourceNotFoundException(ResourceNotFoundException ex) {
        ErrorResponse errorResponse = new ErrorResponse(HttpStatus.NOT_FOUND.value(), ex.getMessage());
        return new ResponseEntity<>(errorResponse, HttpStatus.NOT_FOUND);
    }
}

java
public class ErrorResponse {
    private int status;
    private String message;
    // getters and setters
}