后台控制层控制为非必填即可：
@RequestMapping("/addDo")
@SJson
@SLog(description = "Car_main")
@RequiresPermissions("store.car.manager.add")
public Object addDo(Car_main carMain, @RequestParam(value = "images",required = false) String images, HttpServletRequest req) {
}
Required String parameter 'images' is not present
原文：http://www.cnblogs.com/hedongfei/p/7773278.html