第二步第二步

com.ssm.service.impl   OrderDetailServiceImpl.java/OrderMasterServiceImpl.java

com.ssm.service     OrderDetailService.java/OrderMasterService.java

    /**
     * UsercountServiceImpl
     */
    @Override
    public List<Usercount> queryAll(Usercount usercount) {
        return this.usercountDao.queryAll(usercount);
    }

//    UsercountService
 List<Usercount> queryAll(Usercount usercount);

// providerlist.js
$(".buyProvider").on("click",function(){
		var obj = $(this);
		if(confirm("你确定要购买产品【"+obj.attr("proname")+"】吗？")){
			$.ajax({
				type:"GET",
				url:path+"/provider/buyproduct",
				data:{method:"buyProduct",proid:obj.attr("proid")},
				dataType:"json",
				success:function(data){
					if(data.delResult == "true"){//删除成功：移除删除行
						alert("购买成功");
						obj.parents("tr").remove();
					}else if(data.delResult == "false"){//删除失败
						alert("对不起，购买产品【"+obj.attr("proname")+"】失败");
					}else if(data.delResult == "notexist"){
						alert("对不起，产品【"+obj.attr("proname")+"】不存在");
					}else if(data.delResult == "noMoney"){
						alert("对不起，余额不足！");
					}else{
						alert("对不起，该产品【"+obj.attr("proname")+"】未上架，不能购买");
					}
				},
				error:function(data){
					alert("对不起，购买失败");
				}
			});
		}
	});

<!-- providerlist.jsp -->
<span><a class="buyProvider" href="javascript:;" proid=${provider.id } proname=${provider.proName }><img src="${pageContext.request.contextPath }/images/buy.png" alt="购买" title="购买"/></a></span>