springboot 使用@Valid校验参数 异常消息处理

依赖

• 注解

<dependency>
    <groupId>jakarta.validation</groupId>
    <artifactId>jakarta.validation-api</artifactId>
</dependency>

• 校验支持，包含以上依赖

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-validation</artifactId>
</dependency>

定义校验条件和消息

public class MyDTO {
	@NotBlank(message = "ID不能为空")
	private String id;
}

指定需要校验的参数

@RestController
public class MyController {
	@PostMapping("/api/execute")
    public void execute(
            @Valid @RequestBody MyDTO mydto
    ) {}
}

效果

{"timestamp":"2021-12-08T08:21:34.000000786","status":400,"error":"Bad Request","exception":"org.springframework.web.bind.MethodArgumentNotValidException","message":"Validation failed for object='MyDTO'. Error count: 1","path":"/api/execute"}

异常消息处理

import lombok.Data;
import org.apache.commons.lang3.StringUtils;
import org.springframework.http.HttpStatus;
import org.springframework.validation.FieldError;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.*;

import java.util.List;
import java.util.stream.Collectors;

@ControllerAdvice
@RestController
public class MethodArgumentNotValidExceptionHandler {
    @ResponseStatus(HttpStatus.BAD_REQUEST)
    @ResponseBody
    @ExceptionHandler(MethodArgumentNotValidException.class)
    public Error onException(MethodArgumentNotValidException e) {
        List<FieldError> fieldErrors = e.getFieldErrors();
        List<String> messages = fieldErrors.stream().map(FieldError::getDefaultMessage).collect(Collectors.toList());
        String message = StringUtils.join(messages, ";");
        List<ErrorDetails> errors = fieldErrors.stream().map(
                fieldError -> new ErrorDetails(
                        fieldError.getObjectName(),
                        fieldError.getField(),
                        fieldError.getCode(),
                        fieldError.getDefaultMessage()
                )
        ).collect(Collectors.toList());
        return new Error(message, errors);
    }

    @Data
    static class Error {
        private final String exception = MethodArgumentNotValidException.class.getSimpleName();
        private final String message;
        private final List<ErrorDetails> errors;
    }

    @Data
    static class ErrorDetails {
        private final String objectName;
        private final String field;
        private final String code;
        private final String message;
    }
}

注： 如果不以@RestController注解，消息将以404状态响应返回

效果2

{"exception":"MethodArgumentNotValidException","message":"ID不能为空","errors":[{"objectName":"mydto","field":"id","code":"NotBlank","message":"ID不能为空"}]}