SpringCloud 如何使用feign时的复杂参数传递

@RequestMapping(value = "url",method = RequestMethod.GET)

@RestController
public class ItemController { 
    @Autowired
    private ItemService itemService;
 
    /**
     * 添加
     * @param item
     * @param desc
     * @return
     */
    @RequestMapping("/item/save")
    public Result addItem(@RequestBody Item item, @RequestParam("desc") String desc){
        return itemService.addItem(item, desc);
    }
}

@FeignClient("item-service")
public interface ItemFeignClient {
 
    /**
     * 添加
     * @param item
     * @param desc
     * @return
     */
    @RequestMapping(value = "/item/save",method = RequestMethod.POST)
    Result addItem(@RequestBody TbItem item, @RequestParam("desc") String desc); 

@FeignClient(value = "transaction-feign")
    public interface TransactionApiService {
        /**
         * 交易流水查询 可分页
         *
         * @param param
         * @param pageNum
         * @param pageSize
         * @return
         */
        @RequestMapping(value = "/dealflow/list", method = RequestMethod.POST)
        JsonResultDO dealFlowList(@RequestBody(required = false) DealFlowDo param
                , @RequestParam(value = "pageNum", defaultValue = "1") Integer pageNum
                , @RequestParam(value = "pageSize", defaultValue = "20") Integer pageSize);
    }

/**
 * 交易流水查询 可分页
 * @return JsonResultDO
 */
@RequestMapping(value = "/dealflow/list", method = RequestMethod.POST)
public Page<DealFlowDo> dealFlowList(@RequestBody(required = false) DealFlowDo param
        , @RequestParam(value = "pageNum", defaultValue = "1") Integer pageNum
        , @RequestParam(value = "pageSize", defaultValue = "20") Integer pageSize
        , @RequestParam(value = "userId") Long userId){
    JsonResultDO resultDO = new JsonResultDO();
    Page<DealFlowDo> page = (Page<DealFlowDo> )dealFlowService.queryDealFlowList(userId, param, pageNum, pageSize);
    return page;
}

   /**
     * 根据商户号获取商户信息
     *
     * @param merNo
     * @return
     */
    @RequestMapping(value = "/merchant/{merNo}", method = RequestMethod.GET)
    String getMerchantByMerNo(@PathVariable("merNo") String merNo);