前言

controller层代码主要流程都是：

1.获取前端数据（运用request.getParameter("数据名")）

2.创建user对象（用来传递参数）；创建Service对象（用来使用Service服务的方法）

3.调用Service的方法（传递User参数）

4.跳转到show.jsp展示数据

1.AddUserServlet代码

package controller;

import entity.user;
import service.Imp.UserServiceImp;
import service.UserSrvice;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * @author :LiuYihong
 * @Description :
 * @date : 2022/5/3 14:15
 * @Version 1.0
 */
@WebServlet("/adduser")
public class AddUserServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request, response);
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//        获取前端数据
        int uid = Integer.parseInt(request.getParameter("uid"));
        String uname = request.getParameter("uname");
        String upwd = request.getParameter("upwd");
//       创建服务对象
        UserSrvice userService = new UserServiceImp();
        user user = new user(uid,uname,upwd);
//       调用方法
        userService.saveUser(user);
//        跳转
        request.getRequestDispatcher("show.jsp").forward(request,response);
    }
}

2.DeleteUserServlet代码

package controller;

import entity.user;
import service.Imp.UserServiceImp;
import service.UserSrvice;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * @author :LiuYihong
 * @Description :
 * @date : 2022/5/3 14:15
 * @Version 1.0
 */
@WebServlet("/deleteuser")
public class DeleteUserServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request, response);
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//     获取需要删除的id
        int uid = Integer.parseInt(request.getParameter("uid"));
//        创建对象
        user user = new user(uid);
        UserSrvice userSrvice = new UserServiceImp();
//        调用方法
        userSrvice.deleteUser(user);
//        跳转
        request.getRequestDispatcher("show.jsp").forward(request,response);
    }
}

3.UpdateUserServlet

package controller;

import entity.user;
import service.Imp.UserServiceImp;
import service.UserSrvice;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * @author :LiuYihong
 * @Description :
 * @date : 2022/5/3 14:15
 * @Version 1.0
 */
@WebServlet("/updateuser")
public class UpdateUserServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request, response);
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//        获取前端页面信息
        int oid = Integer.parseInt(request.getParameter("oid"));
        int uid = Integer.parseInt(request.getParameter("uid"));
        String uname = request.getParameter("uname");
        String upwd = request.getParameter("upwd");
//        创建对象
        user user = new user(uid,uname,upwd,oid);
        UserSrvice userSrvice = new UserServiceImp();
//        调用方法
        userSrvice.updateUser(user);
//        跳转
        request.getRequestDispatcher("show.jsp").forward(request,response);
    }

}