Servlet+JSP (Netbeans)：请求的资源不可用

Question

美好的一天。我的 JSP Web 系统出现问题，我正在寻求有关传输功能的帮助。

基本上，传输按钮就像一个停用按钮，一旦我单击它，它就会将传输状态（在我的 SQLdb 中名为 dsTransmit）从“待定”更改为“未激活”。我已经复制了我为删除所做的代码并进行了一些更改，效果很好。

但是，当我在“传输”按钮上执行此操作时，它不会转发要更新的数据。但是，它会发送此错误。

类型状态报告，消息未找到，描述请求的资源不可用。

请注意，我使用的是 Glassfish Server 和 Netbeans。

这是我的代码

DataAccess.java

        public void transmit(int id){
        try {
            String sql = "UPDATE DailySales SET transmit = 'approved' where dsId = ? ";
            PreparedStatement ps = DBUtils.getPreparedStatement(sql);
            ps.setInt(1, id);
            ps.executeUpdate();
        } catch (ClassNotFoundException | SQLException ex) {
            Logger.getLogger(DataAccess.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

Transmit.java

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

package servlet;

import dao.DataAccess;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 *
 * @author Thang
 */
public class Transmit extends HttpServlet {

    /**
     * Processes requests for both HTTP <code>GET</code> and <code>POST</code>
     * methods.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        String idTemp = request.getParameter("id");
        int id = Integer.parseInt(idTemp);
        DataAccess da = new DataAccess();
        da.transmit(id);
        response.sendRedirect("/CRUD_News/AllPost");
    }

    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
    /**
     * Handles the HTTP <code>GET</code> method.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Handles the HTTP <code>POST</code> method.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Returns a short description of the servlet.
     *
     * @return a String containing servlet description
     */
    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>

}

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.1" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd">
    <servlet>
        <servlet-name>EditPost</servlet-name>
        <servlet-class>servlet.EditPost</servlet-class>
    </servlet>
    <servlet>
        <servlet-name>DeletePost</servlet-name>
        <servlet-class>servlet.DeletePost</servlet-class>
    </servlet>
    <servlet>
        <servlet-name>Transmit</servlet-name>
        <servlet-class>servlet.Transmit</servlet-class>
    </servlet>    
    <servlet-mapping>
        <servlet-name>EditPost</servlet-name>
        <url-pattern>/edit</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>DeletePost</servlet-name>
        <url-pattern>/delete</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>Transmit</servlet-name>
        <url-pattern>/transmit</url-pattern>
    </servlet-mapping>    
    <session-config>
        <session-timeout>
            30
        </session-timeout>
    </session-config>
</web-app>

AllPost.jsp（我用于传输功能的按钮）

                    <center><a href="transmit?id=${p.id}" class="btn btn-default" onclick="return confirm('Are you sure you want to transmit this?');">Transmit</a></center>                            

有人可以指出我在这里缺少什么吗？

Answer 1

It works for me 你能展示你的项目吗？

<a href="transmit?id=${p.id}>  ==>  <a href=" transmit.do?id=${p.id}


    <servlet-mapping>
        <servlet-name>Transmit</servlet-name>
        <url-pattern>*.do</url-pattern>
    </servlet-mapping>