java在错误spring引导rest api期间自定义HTTP响应消息

Question

我想为HTTP响应定制一条消息，即

{
    "timestamp": "2020-06-30T00:40:58.558+00:00",
    "status": 417,
    "error": "Expectation Failed",
    "message": "",
    "path": "/test/v1/tests/4ae767e1-ae83-66dd-9180-81160f766d90"
}

我想要的不是上面的消息，而是定制的“消息”：

{
    "timestamp": "2020-06-30T00:40:58.558+00:00",
    "status": 417,
    "error": "Expectation Failed",
    "message": "#/test: 8.0 is not higher or equal to 100",
    "path": "/test/v1/tests/4ae767e1-ae83-66dd-9180-81160f766d90"
}

这是我的异常类：

@ResponseStatus(value = HttpStatus.EXPECTATION_FAILED)
public class ThrowError extends Exception {

    private static final long serialVersionUID = 1L;
    
    public ThrowErrorMessage(String message){

        super(message);
    }

以下是控制器中函数的catch块：

catch(Exception e) 
        {   
  //basically I want e.getMessage() to be the value of the "Message" key
            throw new ThrowErrorMessage(e.getMessage()); 
            
        }
        

Answer 1

可以使用ExceptionHandler根据异常定制错误响应。 您还可以像这样重用DefaultErrorAttributes和ResponseEntityExceptionHandler：https://stackoverflow.com/a/64866190/548473

另见Using ErrorAttributes in our custom ErrorController

Answer 2

如果您使用的是Spring boot 2.3，请在应用程序中设置以下属性。属性将在响应中添加自定义消息

server.error.include-message=always

Answer 3

在控制器中，不要尝试捕捉。相反，直接对方法执行throws，如下所示：

@RestController
@RequestMapping(value = "/api", 
    consumes = { MediaType.APPLICATION_JSON_VALUE }, 
    produces = { MediaType.APPLICATION_JSON_VALUE })
public class YourClassController {
    @GetMapping(value = "/{id}")
    public ResponseEntity<ResponseDto> getSomething(
            @PathVariable("id") String id
    ) throws ThrowError {
        
        //your code, for example:
        HttpStatus httpStatus = HttpStatus.OK;
        ResponseDto responseDto = new ResponseDto;
        responseDto.timestamp(LocalDateTime.now())
            .status(status);

        //maybe some more code

        return new ResponseEntity<>(responseDto, httpStatus);
    }
}

@JsonPropertyOrder({"timestamp", "status", ...})
public class ResponseDto implements Serializable {

    private static final long serialVersionUID = -7377277424125144224L;
    
    //The fields that you want to return if there is no error, example
    @JsonProperty("timestamp")
    @JsonFormat(pattern = "yyyy-MM-dd'T'HH:mm:ss")
    private LocalDateTime timeStamp;

    private Integer status;
    
    //more fields

    //getter, setters and so on.
}

如果有错误，你会得到你想要的，即

{
    "timestamp": "2020-06-30T00:40:58.558+00:00",
    "status": 417,
    "error": "Expectation Failed",
    "message": "#/test: 8.0 is not higher or equal to 100",
    "path": "/test/v1/tests/4ae767e1-ae83-66dd-9180-81160f766d90"
}

如果要进一步自定义错误响应，可以执行以下操作：

@Component
public class CustomErrorAttributes extends DefaultErrorAttributes {

    @Autowired
    private ObjectMapper objectMapper;

    @Override
    public Map<String, Object> getErrorAttributes(WebRequest webRequest, ErrorAttributeOptions options) {
     
        Map<String, Object> map = super.getErrorAttributes(webRequest, options);

        //customize the values of the map here i.e timestamp, status, error, message, path

        return map;
    }
}