如何从 spring@Valid 验证中自定义默认错误消息？

外交部发言人:

public class User {


@NotNull
private String name;


@NotNull
private String password;


//..
}

总监:

@RequestMapping(value = "/user", method = RequestMethod.POST)
public ResponseEntity<String> saveUser(@Valid @RequestBody User user) {
//..
return new ResponseEntity<>(HttpStatus.OK);
}

默认 json 错误:

{"timestamp":1417379464584,"status":400,"error":"Bad Request","exception":"org.springframework.web.bind.MethodArgumentNotValidException","message":"Validation failed for argument at index 0 in method: public org.springframework.http.ResponseEntity<demo.User> demo.UserController.saveUser(demo.User), with 2 error(s): [Field error in object 'user' on field 'name': rejected value [null]; codes [NotNull.user.name,NotNull.name,NotNull.java.lang.String,NotNull]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [user.name,name]; arguments []; default message [name]]; default message [may not be null]],"path":"/user"}

我想有我的自定义 json 为每个错误发生。我如何实现这一点？

142252 次浏览
小开
最佳答案

可以使用 Error/BindingResult 对象执行验证。 向控制器方法中添加“错误”参数，并在发现错误时自定义错误消息。

下面是示例示例，当验证失败时，Error. hasError ()返回 true。

@RequestMapping(value = "/user", method = RequestMethod.POST)
@ResponseBody
public ResponseEntity<String> saveUser(@Valid @RequestBody User user, Errors errors) {
if (errors.hasErrors()) {
return new ResponseEntity(new ApiErrors(errors), HttpStatus.BAD_REQUEST);
}
return new ResponseEntity<>(HttpStatus.OK);
}
小开

如果您希望完全控制每个控制器中的响应消息，请编写一个 ControllerAdvice。例如，这个示例将 MethodArgumentNotValidException转换为一个自定义 json 对象:

import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.ResponseStatus;


import java.util.ArrayList;
import java.util.List;


import static org.springframework.http.HttpStatus.BAD_REQUEST;


/**
* Kudos http://www.petrikainulainen.net/programming/spring-framework/spring-from-the-trenches-adding-validation-to-a-rest-api/
*
*/
@Order(Ordered.HIGHEST_PRECEDENCE)
@ControllerAdvice
public class MethodArgumentNotValidExceptionHandler {


@ResponseStatus(BAD_REQUEST)
@ResponseBody
@ExceptionHandler(MethodArgumentNotValidException.class)
public Error methodArgumentNotValidException(MethodArgumentNotValidException ex) {
BindingResult result = ex.getBindingResult();
List<org.springframework.validation.FieldError> fieldErrors = result.getFieldErrors();
return processFieldErrors(fieldErrors);
}


private Error processFieldErrors(List<org.springframework.validation.FieldError> fieldErrors) {
Error error = new Error(BAD_REQUEST.value(), "validation error");
for (org.springframework.validation.FieldError fieldError: fieldErrors) {
error.addFieldError(fieldError.getField(), fieldError.getDefaultMessage());
}
return error;
}


static class Error {
private final int status;
private final String message;
private List<FieldError> fieldErrors = new ArrayList<>();


Error(int status, String message) {
this.status = status;
this.message = message;
}


public int getStatus() {
return status;
}


public String getMessage() {
return message;
}


public void addFieldError(String path, String message) {
FieldError error = new FieldError(path, message);
fieldErrors.add(error);
}


public List<FieldError> getFieldErrors() {
return fieldErrors;
}
}
}
小开

我知道这是个老问题了,

但我只是碰巧发现了一些相当不错的 文章，它也有一个完美的例子在 Github。

根据 Spring 文档的建议，它基本上使用 @ControllerAdvice。

例如，捕捉400个错误将通过覆盖一个函数来实现:

@ControllerAdvice
public class CustomRestExceptionHandler extends ResponseEntityExceptionHandler {


@Override
protected ResponseEntity<Object> handleMethodArgumentNotValid(final MethodArgumentNotValidException ex, final HttpHeaders headers, final HttpStatus status, final WebRequest request) {
logger.info(ex.getClass().getName());
//
final List<String> errors = new ArrayList<String>();
for (final FieldError error : ex.getBindingResult().getFieldErrors()) {
errors.add(error.getField() + ": " + error.getDefaultMessage());
}
for (final ObjectError error : ex.getBindingResult().getGlobalErrors()) {
errors.add(error.getObjectName() + ": " + error.getDefaultMessage());
}
final ApiError apiError = new ApiError(HttpStatus.BAD_REQUEST, ex.getLocalizedMessage(), errors);
return handleExceptionInternal(ex, apiError, headers, apiError.getStatus(), request);
}
}

(ApiError 类是一个保存状态、消息和错误的简单对象)

小开

一种方法是在实体属性的@NotNull 注释中添加消息。并在控制器请求体中添加@Valid 注释。

外交部发言人:

public class User {
   

@NotNull(message = "User name cannot be empty")
private String name;


@NotNull(message = "Password cannot be empty")
private String password;


//..
}

总监:

@RequestMapping(value = "/user", method = RequestMethod.POST)
public ResponseEntity<String> saveUser(@Valid @RequestBody User user) {
//..
return new ResponseEntity<>(HttpStatus.OK);
}
// Add one
@ExceptionHandler(MethodArgumentNotValidException.class)
public ResponseEntity<List<YourErrorResponse>> handleException(MethodArgumentNotValidException ex) {
// Loop through FieldErrors in ex.getBindingResult();
// return *YourErrorReponse* filled using *fieldErrors*
}
小开 
@ControllerAdvice(annotations = RestController.class)
public class GlobalExceptionHandler implements ApplicationContextAware {


@ExceptionHandler(MethodArgumentNotValidException.class)
@ResponseStatus(HttpStatus.OK)
@ResponseBody
public ApplicationError validationException(MethodArgumentNotValidException e) {


e.printStackTrace();
return new ApplicationError(SysMessageEnum.MSG_005, e.getBindingResult().getAllErrors().get(0).getDefaultMessage());


}


}
小开

你可以这么做

@ExceptionHandler(value = MethodArgumentNotValidException.class)
protected ResponseEntity<Error> handleGlobalExceptions(MethodArgumentNotValidException ex,
WebRequest request) {
log.catching(ex);
return new ResponseEntity<>(createErrorResp(HttpStatus.BAD_REQUEST,
ex.getBindingResult().getFieldErrors().stream().map(err -> err.getDefaultMessage())
.collect(java.util.stream.Collectors.joining(", "))),
HttpStatus.BAD_REQUEST);
}
小开 
@ControllerAdvice
@RestController
public class CustomizedResponseEntityExceptionHandler extends ResponseEntityExceptionHandler {


@Override
protected ResponseEntity<Object> handleMethodArgumentNotValid(
MethodArgumentNotValidException ex, HttpHeaders headers, HttpStatus status, WebRequest request) {


// ex.getBindingResult(): extract the bind result for default message.
String errorResult = ex.getBindingResult().toString();
CustomizedExceptionHandlerResponse exceptionResponse = new CustomizedExceptionHandlerResponse(
errorResult, new Date(), request.getDescription(false));


return new ResponseEntity<>(exceptionResponse, HttpStatus.BAD_REQUEST);
}




}


class CustomizedExceptionHandlerResponse {


private String message;
private String status;
private Date timestamp;


// constuctor, setters, getters...
}
小开

再添加一些信息。 如果你只使用 @Valid，你需要捕捉 BindException。如果你使用 @Valid @RequestBody捕捉 MethodArgumentNotValidException

一些资料来源:
HandlerMethodArgumentResolverComposite.getArgumentResolver(MethodParameter parameter):129-搜索哪个 HandlerMethodArgumentResolver 支持此参数 RequestResponseBodyMethodProcessor.supportsParameter(MethodParameter parameter)-如果参数有注释，返回 true @RequestBody

抛出 MethodArgumentNotValidException 抛出 BindException

小开

为了定制 JSON 格式的错误消息，请执行以下步骤。

- 创建一个@Component，称为 CommonErrorHandler

@Component
public class CommonErrorHandler {
public  Map<String,Object> getFieldErrorResponse(BindingResult result){


Map<String, Object> fielderror = new HashMap<>();
List<FieldError>errors= result.getFieldErrors();
for (FieldError error : errors) {
fielderror.put(error.getField(), error.getDefaultMessage());
}return fielderror;
}


public ResponseEntity<Object> fieldErrorResponse(String message,Object fieldError){
Map<String, Object> map = new HashMap<>();
map.put("isSuccess", false);
map.put("data", null);
map.put("status", HttpStatus.BAD_REQUEST);
map.put("message", message);
map.put("timeStamp", DateUtils.getSysDate());
map.put("filedError", fieldError);
return new ResponseEntity<Object>(map,HttpStatus.BAD_REQUEST);
}
}

——添加 InvalidException 类

public class InvalidDataException extends RuntimeException {


/**
* @author Ashok Parmar
*/
private static final long serialVersionUID = -4164793146536667139L;


private BindingResult result;


public InvalidDataException(BindingResult result) {
super();
this.setResult(result);
}


public BindingResult getResult() {
return result;
}


public void setResult(BindingResult result) {
this.result = result;
}


}

- 介绍@ControllerAdvisory 类

@ControllerAdvice
public class GlobalExceptionHandler extends ResponseEntityExceptionHandler {


@ExceptionHandler(InvalidDataException.class)
public ResponseEntity<?> invalidDataException(InvalidDataException ex, WebRequest request) {


List<FieldError> errors = ex.getResult().getFieldErrors();
for (FieldError error : errors) {
logger.error("Filed Name ::: " + error.getField() + "Error Message :::" + error.getDefaultMessage());
}
return commonErrorHandler.fieldErrorResponse("Error", commonErrorHandler.getFieldErrorResponse(ex.getResult()));
}
}

——在控制器中使用@Valid 并抛出异常

public AnyBeans update(**@Valid** @RequestBody AnyBeans anyBeans ,
BindingResult result) {
AnyBeans resultStr = null;
if (result.hasErrors()) {
**throw new InvalidDataException(result);**
} else {
resultStr = anyBeansService.(anyBeans );
return resultStr;
}
}

——输出将采用 JSON 格式

{
"timeStamp": 1590500231932,
"data": null,
"message": "Error",
"isSuccess": false,
"status": "BAD_REQUEST",
"filedError": {
"name": "Name is mandatory"
}
}

希望这能成功

小开

您可以使用此代码迭代错误并生成自定义错误消息:

import lombok.Data;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;


import javax.validation.ConstraintViolation;
import java.util.List;
import java.util.stream.Collectors;


@ControllerAdvice
public class ExceptionHandlerController {


@ExceptionHandler(MethodArgumentNotValidException.class)
public ResponseEntity<ErrorDto> handleException(MethodArgumentNotValidException ex) {


ErrorDto dto = new ErrorDto(HttpStatus.BAD_REQUEST, "Validation error");


dto.setDetailedMessages(ex.getBindingResult().getAllErrors().stream()
.map(err -> err.unwrap(ConstraintViolation.class))
.map(err -> String.format("'%s' %s", err.getPropertyPath(), err.getMessage()))
.collect(Collectors.toList()));


return ResponseEntity.status(HttpStatus.BAD_REQUEST).body(dto);


}


@Data
public static class ErrorDto {


private final int status;
private final String error;
private final String message;
private List<String> detailedMessages;


public ErrorDto(HttpStatus httpStatus, String message) {
status = httpStatus.value();
error = httpStatus.getReasonPhrase();
this.message = message;
}


}


}

如果出现错误，它会给出如下响应:

{
"status": 400,
"error": "Bad Request",
"message": "Validation error",
"detailedMessages": [
"'yourField' should not be empty."
]
}

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