详解Java后端优雅验证参数合法性

1、首先创建一个测试实体类Person，并携带如上注解，其注解的作用描述在message

package com.clickpaas.pojo;

import com.fasterxml.jackson.annotation.JsonFormat;
import lombok.Data;
import org.hibernate.validator.constraints.Length;
import org.hibernate.validator.constraints.Range;

import javax.validation.constraints.*;
import java.math.BigDecimal;
import java.util.Date;
import java.util.List;

/**
* @author 方延杰
* @version 1.0
* @since 2020/12/10 9:04 下午
*/
@Data
public class Person {

@Null(message = "death必须为null")
 private String death;

@AssertTrue(message = "bool必须为true")
 private boolean bool;

@AssertFalse(message = "fal必须为false")
 private boolean fal;

@Min(value = 1, message = "min必须为数字,其值大于或等于指定的最小值")
 private Integer min;

@Max(value = 10, message = "max必须为数字,其值小于或等于指定的最大值")
 private Integer max;

@DecimalMin(value = "1", message = "minDeci最小不能小于1")
 private BigDecimal minDeci;

@DecimalMax(value = "10", message = "maxDeci最大不能大于10")
 private BigDecimal maxDeci;

@Size(min = 1, max = 2, message = "list集合的长度最小不能小于1,最大不能大于2")
 private List<Object> list;

@Digits(integer = 4, fraction = 2, message = "digits整数位不能超过4个,小数位不能超过2个")
 private BigDecimal digits;

/**
  * 将前台传来的日期数据映射到此字段
  */
 @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd HH:mm:ss", timezone = "GMT+8")
 @Past(message = "past必须为过去的日期")
 private Date past;

@JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd HH:mm:ss", timezone = "GMT+8")
 @Future(message = "future必须为将来的日期")
 private Date future;

@Pattern(regexp = "^1[3|4|5|7|8][0-9]{9}$", message = "phone必须符合正则表达式")
 private String phone;

@Email(message = "email必须是邮箱格式")
 private String email;

@Length(min = 1, max = 2, message = "length长度最小不能小于1,最大不能大于2")
 private String length;

@NotEmpty(message = "id不能为null，长度大于0")
 private String id;

@Range(min = 1, max = 12, message = "month最小不能小于1,最大不能大于12")
 private Integer month;

@NotBlank(message = "name不能为null,字段串长度大于0（限字符串）")
 private String name;
}

2、封装返回响应体

package com.clickpaas.response;

import lombok.AllArgsConstructor;
import lombok.Data;

/**
* @author 方延杰
* @version 1.0
* @since 2019/7/3 4:32 下午
*/
@Data
@AllArgsConstructor
public class CodeMsg {

private int code;

private String msg;

/**
  * 失败
  */
 public static CodeMsg SERVER_ERROR = new CodeMsg(500, "服务端异常");

}

package com.clickpaas.response;

import lombok.AllArgsConstructor;
import lombok.Data;

/**
* @author 方延杰
* @version 1.0
* @since 2019/7/3 4:35 下午
*/
@Data
@AllArgsConstructor
public class Result<T> {

/**
  * 返回状态码 除200其余全部失败
  */
 private int code;

/**
  * 返回信息 除success其余全部失败
  */
 private String msg;

/**
  * 泛型数据
  */
 private T data;

/**
  * 成功时返回的类型
  *
  * @param data 数据
  * @param <T> 泛型
  * @return 泛型数据
  */
 public static <T> Result<T> success(T data) {
   return new Result<>(200, "success", data);
 }

public static <T> Result<T> fail(CodeMsg codeMsg) {
   return new Result<>(codeMsg);
 }
 private Result(CodeMsg codeMsg) {
   if (codeMsg == null) {
     return;
   }
   this.code = codeMsg.getCode();
   this.msg = codeMsg.getMsg();
 }

}

3、创建使用增强器拦截并返回异常信息

package com.clickpaas.config;

import com.clickpaas.response.CodeMsg;
import com.clickpaas.response.Result;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;

import javax.servlet.http.HttpServletRequest;
import java.util.Objects;

/**
* @author 方延杰
* @version 1.0
* @since 2018/12/10 4:59 下午
*/
@RestControllerAdvice
public class GlobalExceptionInterceptor {

@ExceptionHandler(value = MethodArgumentNotValidException.class)
 public Result<Object> exceptionHandler(HttpServletRequest request, Exception e) {
   String errMsg = "处理失败";
   if (e instanceof MethodArgumentNotValidException) {
     // 拿到参数校验具体异常信息
     errMsg = Objects.requireNonNull(((MethodArgumentNotValidException) e).getBindingResult().getFieldError()).getDefaultMessage();
   }
   return Result.fail(new CodeMsg(500, errMsg));
 }
}

4、创建控制层测试

package com.clickpaas.controller;

import com.clickpaas.pojo.Person;
import org.springframework.validation.annotation.Validated;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;

/**
* @author 方延杰
* @version 1.0
* @since 2020/12/10 9:03 下午
*/
@RestController
public class ValidController {

@PostMapping("/valid")
 public String valid(@Validated @RequestBody Person person) {
   return "success";
 }

}

5、测试符合验证请求体访问，请求体如下：

{
 "death":null,
 "bool":true,
 "fal":false,
 "min":1,
 "max":10,
 "minDeci":1,
 "maxDeci":10,
 "list":[
   {},{}
 ],
 "digits":1144.12,
 "past":"2020-10-01 10:00:00",
 "future":"2022-10-01 10:00:00",
 "phone":"15900445584",
 "email":"yanjie.fang@clickpaas.com",
 "length":"ab",
 "id":" ",
 "name":"a"
}

6、故意修改不符合验证的数据

7、如果想做整体验证，如下：

package com.clickpaas.uitl;

import javax.validation.ConstraintViolation;
import javax.validation.Validation;
import javax.validation.Validator;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

/**
* Bean整体校验工具类
*
* @author 方延杰
* @version 1.0
* @since 2020/12/10 10:08 下午
*/
public class ValidatorUtils {

private static final Validator VALIDATOR = Validation.buildDefaultValidatorFactory().getValidator();

/**
  * Bean整体校验，有不合规范，拼接message
  */
 public static String validate(Object obj, Class<?>... groups) {

StringBuilder errorMessage = new StringBuilder();

Set<ConstraintViolation<Object>> resultSet = VALIDATOR.validate(obj, groups);
   if (resultSet.size() > 0) {
     //如果存在错误结果，则将其解析并进行拼凑后异常抛出
     List<String> errorMessageList = resultSet.stream().map(ConstraintViolation::getMessage).collect(Collectors.toList());
     errorMessageList.forEach(o -> errorMessage.append(o).append(";"));
   }
   return errorMessage.toString();
 }

}

8、整体测试类

来源：https://blog.csdn.net/weixin_48314739/article/details/111012090