一個簡單的Java MVC模式示例

package com.neuq.control;           //視圖層

import java.io.IOException;
import java.sql.SQLException;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.neuq.dao.UserDao;
import com.neuq.service.UserService;
import com.neuq.vo.UserVO;
public class UserManage extends HttpServlet {

public void doGet(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
    this.doPost(request, response);
}


//增加用戶
public void addUser(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException, SQLException {
    //獲取客戶端傳進來的數據
    String userName =(String)request.getParameter("userName");
    String password = (String)request.getParameter("password");
    String sex = (String)request.getParameter("sex");
    String hobby = (String)request.getParameter("hobby");
    String email = (String)request.getParameter("email");
    String telephone = (String)request.getParameter("telephone");
    String province = (String)request.getParameter("province");

    UserVO user = new UserVO();        //建立一個實例，利用控制層
    user.setUserName(userName);
    user.setPassword(password);
    user.setSex(sex);
    user.setHobby(hobby);
    user.setEmail(email);
    user.setTelephone(telephone);
    user.setProvince(province);


    UserService userService = new UserService();
    int resultCount=userService.addUser(user);
    if(resultCount<=0){
        request.setAttribute("info","添加失敗！" );
    }else{
        request.setAttribute("info", "添加成功！");
    }

    request.getRequestDispatcher("../info.jsp").forward(request, response);//請求轉發
}

//刪除用戶
public void deleteUser(HttpServletRequest request,
        HttpServletResponse response) throws IOException {
    String userName = request.getParameter("userName");
    UserService userService = new UserService();
    boolean flag =userService.deleteUser(userName);
    if (flag) {
        request.setAttribute("info", "刪除數據成功！");
    } else {
        request.setAttribute("info", "刪除數據失敗！");
    }
    try {
        request.getRequestDispatcher("../info.jsp").forward(request, response);
    } catch (ServletException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } 
}




//查詢用戶
public void selectUser(HttpServletRequest request,
        HttpServletResponse response) throws ServletException, IOException {
    String userName =(String)request.getParameter("userName");

    UserDao userDao = new UserDao();
    List list = (List)userDao.getUsers(userName);
    request.setAttribute("result", list);

    request.getRequestDispatcher("../ShowMessage.jsp").forward(request, response);
}

//修改用戶
public void updateUser(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException, SQLException {
    String userName=(String)request.getParameter("userName");
    String password = (String)request.getParameter("password");
    String sex = (String)request.getParameter("sex");
    String hobby = (String)request.getParameter("hobby");
    String email = (String)request.getParameter("email");
    String telephone = (String)request.getParameter("telephone");
    String province = (String)request.getParameter("province");

    UserVO user = new UserVO();        //建立一個實例，利用控制層
    user.setUserName(userName);
    user.setPassword(password);
    user.setSex(sex);
    user.setHobby(hobby);
    user.setEmail(email);
    user.setTelephone(telephone);
    user.setProvince(province);

    UserService userService = new UserService();
    int resultCount=userService.updateUser(user);
    if(resultCount<=0){
        request.setAttribute("info", "修改數據失敗！");
    }else{
        request.setAttribute("info", "修改數據成功！");
    }
    try {
        request.getRequestDispatcher("../info.jsp").forward(request, response);
    } catch (ServletException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } 
}



public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
    String method=(String)request.getParameter("method");
    try {
        if("add".equals(method)){ 
                addUser(request,response);
        }else if("select".equals(method)){
            selectUser(request,response);
        }else if("update".equals(method)){
            updateUser(request,response);
        }else if("delete".equals(method)){
            deleteUser(request,response);
        }
            } catch (SQLException e) {
                e.printStackTrace();
            }
}




}
 </pre>