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servlet用的baseservlet继承,反射获取url地址中的method的地址


@WebServlet("/orders")

public class OrderServlet extends BaseServlet{



// 3.增加配送通知单
    public void addOrder(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException {
        // 测试是否调用此方法
        System.out.println("进入addOrder()");
        // 获取来自providerManage.jsp中id为fm的form表单传过来的数据,用来新增配送通知单.
        String cidStr = req.getParameter("cid");
        String username = req.getParameter("username");
        String telephone = req.getParameter("telephone");
        String address = req.getParameter("address");
        String name = req.getParameter("name");

        //测试数据接收是否成功
        System.out.println("cid : "+cidStr);
        System.out.println("username : "+username);
        System.out.println("address : "+address);
        System.out.println("telephone : "+telephone);

        // 把有些参数转换成int类,因为这些参数在数据库中是int类型
        int cid = Integer.parseInt(cidStr);

        OrderService orderService = new OrderService();
        orderService.addOrder(username, username, address, telephone, cid);

        // 获取该用户通知单,再次发送至页面
        OrderService service = new OrderService();
        List<Orders> orderList = service.findAllOrdersByCid(cid);
        req.setAttribute("orderList", orderList);
        System.out.println("orderList :　"+orderList);
        req.getRequestDispatcher("customer_orderlist.jsp").forward(req, resp);

        System.out.println("addOrder结束");

    }

jsp页面中的表单发送至该servlet,但是控制台打印始终显示为空

<form action="${pageContext.request.contextPath}/orders?oid=${oid}&cid=${cid}">
        <table border="1px">

请教同学后解决了问题

1.首先jsp页面中加上以下代码

<form action="${pageContext.request.contextPath}/orders?oid=${oid}&cid=${cid}">
        <table border="1px">
        <!--添加下面的input-->
        <input type="hidden" name="method" value="addOrder" />

一个隐藏的input

2.再把orders?后面的oid=





{oid}&cid=



{oid}&cid=


${oid}&cid=$
{cid}给删掉

<form action="${pageContext.request.contextPath}/orders">
        <table border="1px">
        <!--添加下面的input-->
        <input type="hidden" name="method" value="addOrder" />

原因: servlet用了反射的方法来获取方法名,在servlet方法中用req.getParameters(),就无法获取jsp中form传来的数据,

因此,在jsp中加上一个隐藏的input,把方法名传过去也一样,其他数据也可用隐藏的input传到servlet去