前端jsp頁面：
 <td>
     <a href="${ctx}/goods/del/${goodItem.id};" type="submit" >刪除</a>
</td>


後臺controller:
  @RequestMapping("/del/{gid}")
    public String del(@PathVariable("gid")long gid, Model model){
        if(String.valueOf(gid)!=null &&String.valueOf(gid)!=""){
            System.out.println("gid"+gid);
            goodsService.del(gid);
        }
        else{
            System.out.print("controller del gid為空");
        }
        List<Goods> goodsList=goodsService.findAll();
        model.addAttribute("goodsList",goodsList);
        return "redirect:/goods/list"; //重定向
    }