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