自定义Spring Boot中@Valid注解的验证错误响应

@RequestMapping(
    method = RequestMethod.GET,
    value = "/true-match",
    produces = {"application/json"})
public ResponseEntity<ResponseWrapper<List<TrueMatch>>> getTrueMatch(
    @Valid Details details) {
    // 业务逻辑
    return ResponseEntity.ok(...);
}

// Details 类示例
public class Details {
    @NotNull(message = "传输类型不能为空")
    private TransmissionType transmissionType;
    // 其他字段...

    // Getter/Setter
    public TransmissionType getTransmissionType() {
        return transmissionType;
    }

    public void setTransmissionType(TransmissionType transmissionType) {
        this.transmissionType = transmissionType;
    }
}

// 枚举类型示例
public enum TransmissionType {
    AUTOMATIC, MANUAL;
}

{
    "status": 400,
    "validationErrors": {
        "transmissionType": "Failed to convert property value of type 'java.lang.String' to required type 'my.application.model.TransmissionType' for property 'transmissionType'; nested exception is org.springframework.core.convert.ConversionFailedException: Failed to convert from type [java.lang.String] to type [@javax.validation.constraints.NotNull ie.aviva.services.motor.cartellservice.model.TransmissionType] for value 'foo'; nested exception is java.lang.IllegalArgumentException: No enum constant ie.aviva.services.motor.cartellservice.model.TransmissionType.automatic'"
    },
    "title": "Bad Request"
}

{
    "status": 400,
    "validationErrors": {
        "transmissionType": "传输类型'foo'无效，请提供'AUTOMATIC'或'MANUAL'"
    },
    "title": "Bad Request"
}

import lombok.Builder;
import lombok.Data;
import org.springframework.http.HttpStatus;

import java.time.LocalDateTime;
import java.util.Map;

@Data
@Builder
public class CustomErrorResponse {
    private LocalDateTime timestamp;
    private HttpStatus status;
    private int statusCode;
    private String title;
    private Map<String, String> validationErrors; // 字段名 -> 错误消息
    private String path; // 可选：请求路径
}

import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.validation.FieldError;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;

import java.time.LocalDateTime;
import java.util.HashMap;
import java.util.Map;
import java.util.Objects;

@RestControllerAdvice
public class GlobalValidationExceptionHandler {

    @ExceptionHandler(MethodArgumentNotValidException.class)
    public ResponseEntity<CustomErrorResponse> handleValidationExceptions(
            MethodArgumentNotValidException ex) {

        Map<String, String> errors = new HashMap<>();
        // 遍历所有验证错误
        ex.getBindingResult().getAllErrors().forEach(error -> {
            String fieldName = "unknown";
            String errorMessage = error.getDefaultMessage();

            if (error instanceof FieldError) {
                fieldName = ((FieldError) error).getField();
                // 对于枚举转换失败，FieldError的默认消息可能仍包含技术细节
                // 这里可以进一步判断错误类型并自定义消息
                if (Objects.requireNonNull(error.getCode()).equals("typeMismatch")) {
                    // 假设我们知道这是枚举转换失败，可以构造更友好的消息
                    // 实际应用中可能需要更复杂的逻辑来提取预期枚举值
                    errorMessage = String.format("参数'%s'的值'%s'无效，请检查输入格式或可选值。",
                                                 fieldName, ((FieldError) error).getRejectedValue());
                }
            } else {
                // 处理非字段级别的对象错误
                fieldName = error.getObjectName();
            }
            errors.put(fieldName, errorMessage);
        });

        CustomErrorResponse errorResponse = CustomErrorResponse.builder()
                .timestamp(LocalDateTime.now())
                .status(HttpStatus.BAD_REQUEST)
                .statusCode(HttpStatus.BAD_REQUEST.value())
                .title("参数验证失败")
                .validationErrors(errors)
                // .path(request.getRequestURI()) // 如果需要，可以从 HttpServletRequest 获取
                .build();

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

    // 可以添加其他异常处理器，例如处理通用的Exception
    @ExceptionHandler(Exception.class)
    public ResponseEntity<CustomErrorResponse> handleGenericException(Exception ex) {
        // ... 处理通用异常，返回500错误等
        return new ResponseEntity<>(CustomErrorResponse.builder()
                .timestamp(LocalDateTime.now())
                .status(HttpStatus.INTERNAL_SERVER_ERROR)
                .statusCode(HttpStatus.INTERNAL_SERVER_ERROR.value())
                .title("服务器内部错误")
                .validationErrors(Map.of("error", ex.getMessage()))
                .build(), HttpStatus.INTERNAL_SERVER_ERROR);
    }
}