问： 假如id为非必需参数，可以为空，应该怎么处理

                      @RequestMapping  (value =  "/get/{id}/{userId}"  , method = RequestMethod.GET)
    public Result getMemberShip(  @PathVariable  (  "id"  ) int id,  @PathVariable  (  "userId"  ) int userId) {  

可以指定多个匹配路径

                    @RequestMapping(value = {  "/get/{userId}"  ,   "/get/{id}/{userId}"  }, method = RequestMethod.GET)   

然后设置参数非必须

                    @PathVariable  (required =   false  )   String   id  

示例

                   @ApiOperation("获取订单接口")
  @ApiImplicitParams({
          @ApiImplicitParam(name = "pin", paramType = "path", dataType = "String", value = "账号", required = true),
          @ApiImplicitParam(name = "phone", paramType = "path", dataType = "String", value = "电话号码", required = false)
  })
  @ApiResponses({@ApiResponse(code = 501, message = "自定义异常xxx"), @ApiResponse(code = 500, message = "500", response = Errors.class)})
  @GetMapping(value = {"/list/{pin}/{phone}", "/list/{pin}"})
  public List<OrderBaseVO> getOrderList(@PathVariable String pin, @PathVariable(required = false) String phone) {
  }