每个程序员都能写出简介优雅的restful接口validation（springboot）

背景
最近在开发的时候贼烦，本来是想写一个非常简洁而优雅的restful风格的代码的，controller层本来是想超级简单，可是奈何，一个接口包含输入请求参数总是需要我们去效验的。

@PostMapping("/saveIntuitiveLike")
    @AdminValidable(validType = 2)
    @ApiOperation(value = "直观像模块-新建直观像", notes = "", httpMethod = "POST")
    public Response<?> saveIntuitiveLike(HttpServletRequest request, HttpServletResponse response,
                                         @ApiParam(value = "直观像模块-新建直观像") @RequestBody List<SaveIntuitiveLikeNodeReq> reqList) throws Exception { 
        String adminName = this.getCurrentAdminName(request);
        logger.info("直观像模块-新建直观像:saveIntuitiveLike,adminName is {} req is {}", adminName, JsonUtil.tranObjToStr(reqList));
        //参数
        if (!UtilEmpty.isNullorEmpty(reqList)) { 
            reqList.forEach(x->{ 
                try { 
                    checkIntuitiveLike(x);
                } catch (OkyaException e) { 
                    logger.info("直观像模块-新建直观像:saveIntuitiveLike error msg is ", JsonUtil.tranObjToStr(e));
                    e.printStackTrace();
                }
            });
        }
        intuitiveLikeBusiness.saveIntuitiveLike(reqList);
        return Response.ok("创建成功");
    }
public void checkIntuitiveLike(SaveIntuitiveLikeNodeReq req) throws OkyaException { 
        if (UtilEmpty.isNullorEmpty(req)) { 
            try { 
                throw new OkyaException("IntuitiveLikeBusiness", "checkPara", API_RESULT.PARA_CAN_NOT_EMPTY);
            } catch (OkyaException e) { 
                e.printStackTrace();
            }
        }
        boolean b = paramCheck( req.getAnswerJudgeTime(), req.getAnswerLists(), req.getAnswerShowTime(),
                req.getAnswerTime(), req.getIntuitiveShowTime(), req.getIntuitiveType(), req.getLessonUnique());
        if (!b) { 
            throw new OkyaException("IntuitiveLikeBusiness", "checkPara", API_RESULT.PARA_CAN_NOT_EMPTY);
        }
    }

然而效验就是归效验，这样写代码是简单了，然并卵，可是前段并不知道具体是哪个参数是空的呀，这就很蛋疼了。所以呢 老是会存在到底哪个参数不能非空呀。所以我们就的在swagger上标明到底哪个参数是否是要非空，可是要是哪天需求改了呢，参数就很有可能忘记修改

这个痛点一直伴随了我这苦逼的程序员很久，终于曙光到来，发现validation能够非常好的处理这个问题，废话不多说，我们直接来个Demo展现一下风采吧。

pom文件引入依赖包

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

编写DTO类

@Data
@ApiModel
public class UserSaveReq implements Serializable { 
    @NotEmpty(message = "用户名字不能为空")
    @ApiModelProperty(value = "姓名")
    private String user;
    @ApiModelProperty(value = "手机号码")
    @NotBlank(message = "手机号不能为空")
    private String phone;
}

编写controller层

@PostMapping("/saveUser")
    public String saveUser(HttpServletRequest request, HttpServletResponse response,
                         @ApiParam(value = "查询订单列表") @RequestBody @Valid UserSaveReq req){ 
        UserModel userModel = new UserModel();
        BeanUtils.copyProperties(req,userModel);
        userService.save(userModel);
        return "添加成功";
    }

记得这里必须要加上@Valid注解

测试一波


接口返回400，在defaultMessage上返回了我们刚才在Dto上配置的message内容，这样展示是 好像是有点不太友好，没关系我们使用@ControllerAdvice拦截异常

• 首先我们封装下Response输出格式

  package com.evan;

  import io.swagger.annotations.ApiModel;
  import io.swagger.annotations.ApiModelProperty;
  import lombok.Data;

  /**

  • 请求响应结果
  • @author EvanYang
    *

  • @param
    */
    @ApiModel(description = “返回对象”)
    @Data
    public class Response {
    public final static String CODE_OK = “200”;
    public final static String MSG_OK = “ok”;
    public final static String CODE_ERROR = “5000”;
    public final static String MSG_ERROR = “error”;
    @ApiModelProperty(value = “返回码，200为成功，其他为失败”, required = true)
    private String resultCode;
    @ApiModelProperty(value = “返回码描述”, required = true)
    private String resultMsg;
    @ApiModelProperty(value = “结果签名”, required = true)
    private String sign;
    @ApiModelProperty(value = “详细数据”, required = false)
    private T data;

    public Response() {

     resultCode = CODE_OK;
     resultMsg = MSG_OK;

    }

    public Response(String resultCode, String resultMsg) {

     this.resultCode = resultCode;
     this.resultMsg = resultMsg;

    }

    /**

    • 成功结果
      *
    • @param data
    • @param

    • @return
      */
      public static Response ok(T data, String sign) {
      Response response = new Response<>();
      response.setData(data);
      response.setSign(sign);
      return response;
      }

      /**

    • 成功结果
      *
    • @param data
    • @param
    • @return
      */
      public static Response ok(T data) {
      Response response = new Response<>();
      response.setData(data);
      return response;
      }

    /**
     * 失败结果
     *
     * @param data
     * @param      <T>
     * @return
     */
    public static <T> Response<T> error(T data) { 
        Response<T> response = new Response<>();
        response.setData(data);
        return error(CODE_ERROR, MSG_ERROR, data);
    }
    /**
     * 失败结果
     *
     * @param code
     * @param msg
     * @param data
     * @param      <T>
     * @return
     */
    public static <T> Response<T> error(String code, String msg, T data) { 
        Response<T> response = new Response<>(code, msg);
        response.setData(data);
        return response;
    }
    /**
     * 失败结果
     *
     * @param data
     * @param      <T>
     * @return
     */
    public static <T> Response<T> error(Exception exception, T data) { 
        return errorException(exception, data);
    }
    /**
     * 失败结果
     * @param data
     * @param      <T>
     * @return
     */
    public static <T> Response<T> errorException(Exception exception, T data) { 
        Response<T> response = new Response<>();
        response.setData(data);
        response.setResultMsg(exception.getMessage());
        return response;
    }
}

• 自定义异常类BusinessException

  package com.evan.except;

  /**

  • @author evanYang
  • @version 1.0

  • @date 04/11/2020 10:49
    */
    public class BusinessException extends RuntimeException {
    private String message;
    private Throwable throwable;
    public BusinessException(String message) {

     this(message,null);

    }

    public BusinessException(String message,Throwable throwable) {

     super(message,throwable);

    }
    }

• 定义异常拦截类 程序中抛出的所有异常都会被拦截然后统一输出，避免输出不友好的异常提示信息。

  package com.evan.except;

  import com.evan.Response;
  import org.springframework.util.CollectionUtils;
  import org.springframework.validation.ObjectError;
  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.RestControllerAdvice;

  import javax.validation.ConstraintViolation;
  import javax.validation.ConstraintViolationException;
  import java.util.List;
  import java.util.Set;

  /**

  • @author evanYang
  • @version 1.0

  • @date 04/11/2020 10:50
    */
    @ControllerAdvice
    @RestControllerAdvice
    public class GlobalExceptionHandler {
    @ExceptionHandler(Exception.class)
    public Response<?> handleException(Exception e) {

     return Response.error( e.getMessage());

    }

    /**

    • 拦截业务异常
      */
      @ExceptionHandler(BusinessException.class)
      public Response<?> handleBusinessException(BusinessException e) {
      return Response.error( e.getMessage());
      }

      /**

    • 拦截参数校验异常
      */
      @ExceptionHandler(MethodArgumentNotValidException.class)
      public Response<?> handleMethodArgumentNotValidException(MethodArgumentNotValidException methodArgumentNotValidException) {
      StringBuilder errorMessage=new StringBuilder();
      List objectErrors=methodArgumentNotValidException.getBindingResult().getAllErrors();
      if (!CollectionUtils.isEmpty(objectErrors)) {

       for (int i = 0; i < objectErrors.size(); i++) { 
           if (i == 0) { 
               errorMessage.append(objectErrors.get(i).getDefaultMessage());
           } else { 
               errorMessage.append(",");
               errorMessage.append(objectErrors.get(i).getDefaultMessage());
           }
       }

      }else {

       errorMessage.append("MethodArgumentNotValidException occured.");

      }
      return Response.error(“400”, errorMessage.toString(),null);
      }

      /**

    • 拦截自定义约束异常
      */
      @ExceptionHandler(ConstraintViolationException.class)
      public Response<?> handle(ConstraintViolationException constraintViolationException) {
      Set> violations = constraintViolationException.getConstraintViolations();
      String errorMessage = “”;
      if (!violations.isEmpty()) {

       StringBuilder builder = new StringBuilder();
       violations.forEach(violation -> builder.append(" " + violation.getMessage()));
       errorMessage = builder.toString();

      } else {

       errorMessage = "ConstraintViolationException occured.";

      }
      return Response.error(“400”, errorMessage,null);
      }

}

这会我们再来看看我们的返回信息

最后文末附上GitHUb上的工程地址：GitHub项目链接