异常处理

全局异常处理

@ControllerAdvice

@ControllerAdvice
public class GlobalExceptionHandler {
    
    @ExceptionHandler(ResourceNotFoundException.class)
    public ResponseEntity<ErrorResponse> handleResourceNotFound(
        ResourceNotFoundException ex,
        WebRequest request
    ) {
        ErrorResponse error = new ErrorResponse(
            HttpStatus.NOT_FOUND.value(),
            ex.getMessage(),
            request.getDescription(false),
            LocalDateTime.now()
        );
        return ResponseEntity.status(HttpStatus.NOT_FOUND).body(error);
    }
    
    @ExceptionHandler(MethodArgumentNotValidException.class)
    public ResponseEntity<Map<String, String>> handleValidationExceptions(
        MethodArgumentNotValidException ex
    ) {
        Map<String, String> errors = new HashMap<>();
        ex.getBindingResult().getAllErrors().forEach(error -> {
            String fieldName = ((FieldError) error).getField();
            String errorMessage = error.getDefaultMessage();
            errors.put(fieldName, errorMessage);
        });
        return ResponseEntity.badRequest().body(errors);
    }
    
    @ExceptionHandler(Exception.class)
    public ResponseEntity<ErrorResponse> handleGlobalException(
        Exception ex,
        WebRequest request
    ) {
        ErrorResponse error = new ErrorResponse(
            HttpStatus.INTERNAL_SERVER_ERROR.value(),
            "An unexpected error occurred",
            request.getDescription(false),
            LocalDateTime.now()
        );
        return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(error);
    }
}

@Data
@AllArgsConstructor
public class ErrorResponse {
    private int status;
    private String message;
    private String path;
    private LocalDateTime timestamp;
}

自定义异常

@ResponseStatus(HttpStatus.NOT_FOUND)
public class ResourceNotFoundException extends RuntimeException {
    public ResourceNotFoundException(String message) {
        super(message);
    }
}

@ResponseStatus(HttpStatus.BAD_REQUEST)
public class InvalidRequestException extends RuntimeException {
    public InvalidRequestException(String message) {
        super(message);
    }
}

ResponseEntityExceptionHandler

@ControllerAdvice
public class CustomExceptionHandler extends ResponseEntityExceptionHandler {
    
    @Override
    protected ResponseEntity<Object> handleMethodArgumentNotValid(
        MethodArgumentNotValidException ex,
        HttpHeaders headers,
        HttpStatusCode status,
        WebRequest request
    ) {
        Map<String, String> errors = new HashMap<>();
        ex.getBindingResult().getFieldErrors().forEach(error ->
            errors.put(error.getField(), error.getDefaultMessage())
        );
        
        return ResponseEntity.badRequest().body(errors);
    }
}

异常处理最佳实践

1. 使用语义化的异常类
2. 返回标准化的错误响应
3. 记录异常日志
4. 不暴露敏感信息
5. 提供有用的错误消息

返回第二章概览