Spring启动自定义http错误响应？

Question

HTTP/1.1 500 Internal Server Error
{
    "timestamp": 1412685688268,
    "status": 500,
    "error": "Internal Server Error",
    "exception": "com.example.CustomException",
    "message": null,
    "path": "/example"
}

@ControllerAdvice
class CustomResponseEntityExceptionHandler extends ResponseEntityExceptionHandler {

    @ExceptionHandler
    @ResponseStatus(HttpStatus.BAD_REQUEST)
    @ResponseBody
    ErrorMessage handleBadCredentials(CustomException e) {
        return new ErrorMessage("Bad things happened");
    }
}

@XmlRootElement
public class ErrorMessage(
    private String error;

    public ErrorMessage() {
    }

    public ErrorMessage(String error) {
        this.error = error;
    }

    public String getError() {
        return error;
    }

    public void setError(String error) {
        this.error = error;
    }
)

然而，这产生了（正如怀疑的那样）完全不同的反应：

HTTP/1.1 400 Bad Request
{
    "error": "Bad things happened"
}

Answer 1

正如@Zeroflagl提到的，Spring Boot在org.springframework.Boot.autoconfigure.web.Defaulterrorattributes中创建了“标准”错误响应主体。与您的需求类似，我想利用所有这些，但只是增加了一个由我的一些异常提供的“type”字段。

我实现了一个组件，该组件对DefaulTerrorAttributes进行了子类划分。Spring Boot自动拿起它，并使用我的而不是默认的。

@Component
public class ExtendedErrorAttributes extends DefaultErrorAttributes {
    @Override
    public Map<String, Object> getErrorAttributes(RequestAttributes requestAttributes, 
                                                  boolean includeStackTrace) {
        final Map<String, Object> errorAttributes = 
            super.getErrorAttributes(requestAttributes, 
                                     includeStackTrace);

        final Throwable error = super.getError(requestAttributes);
        if (error instanceof TypeProvider) {
            final TypeProvider typeProvider = (TypeProvider) error;
            errorAttributes.put("type", typeProvider.getTypeIdentifier());
        }

        return errorAttributes;
    }
}

这样，我得到了一个增强的JSON响应主体，例如

{
  "timestamp": 1488058582764,
  "status": 429,
  "error": "Too Many Requests",
  "exception": "com.example.ExternalRateLimitException",
  "message": "DAILY_LIMIT: too many requests",
  "path": "/api/lookup",
  "type": "DAILY_LIMIT"
}