用戶登錄驗(yàn)證(MVC模式)

1、基于MVC模式的用戶登錄驗(yàn)證系統(tǒng)一、 項(xiàng)目文件結(jié)構(gòu)：二、View視圖部分Login.jsp 用戶登錄 用戶名: 密  碼: LoginCL.jsp Wel.jsp 登陸成功！恭喜你！ 重新登陸 顯示所有用戶列表 UserList.jsp 用戶信息列表 用戶ID用戶名用戶密碼用戶級(jí)別 % for(int i=0;i 三、Model模型部分UserBean.javapackage com.li.model;public class UserBean private int userId;private String username;private String passwd;

2、private int grade;public int getUserId() return userId;public void setUserId(int userId) this.userId = userId;public String getUsername() return username;public void setUsername(String username) this.username = username;public String getPasswd() return passwd;public void setPasswd(String passwd) thi

3、s.passwd = passwd;public int getGrade() return grade;public void setGrade(int grade) this.grade = grade;UserBeanDao.javapackage com.li.model;import java.sql.*;import java.util.*;public class UserBeanDao private Statement sm = null;private ResultSet rs = null;private Connection ct = null;private int

4、pageCount = 0;private int rowCount = 0;private int pageSize = 3;public void close() / 關(guān)閉各種打開的資源try if (rs != null) rs.close();rs = null;if (sm != null) sm.close();sm = null;if (ct != null) ct.close();ct = null; catch (Exception e) e.printStackTrace();/ 打印異常，以便修改public ArrayList getUserList() ArrayLi

5、st al = new ArrayList();try ct = new ConnDB().getConn();sm = ct.createStatement();rs = sm.executeQuery(select * from users);while (rs.next() UserBean ub = new UserBean();ub.setUserId(rs.getInt(1);ub.setUsername(rs.getString(2);ub.setPasswd(rs.getString(3);ub.setGrade(rs.getInt(4);al.add(ub); / 將al放到

6、arrayList中 catch (Exception e) e.printStackTrace(); finally this.close();return al;public boolean checkUser(String u, String p) boolean b = false;try ct = new ConnDB().getConn();/ 獲取ConnDB中的方法，操作數(shù)據(jù)庫sm = ct.createStatement();rs = sm.executeQuery(select passwd from users where username=+ u + );if (rs.

7、next() if (rs.getString(1).equals(p) b = true; catch (Exception e) e.printStackTrace(); finally / 關(guān)閉各種打開的資源，釋放內(nèi)存this.close();return b;ConnDB.javapackage com.li.model;import java.sql.*;public class ConnDB private Connection ct=null;public Connection getConn()tryClass.forName(sun.jdbc.odbc.JdbcOdbcDri

8、ver); ct=DriverManager.getConnection(jdbc:odbc:users);catch(Exception e)e.printStackTrace(); return ct;四、Controller部分LoginCheckServlet.javapackage com.li.controller;import java.io.IOException;import java.io.PrintWriter;import java.util.ArrayList;import javax.servlet.ServletException;import javax.ser

9、vlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import com.li.model.*;public class LoginCheckServlet extends HttpServlet public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException /得

10、到用戶名和密碼 String u=request.getParameter(username); String p=request.getParameter(passwd);/使用模型，完成驗(yàn)證 UserBeanDao ubdao=new UserBeanDao(); request.setAttribute(uname, u); if(ubdao.checkUser(u, p) /在跳轉(zhuǎn)到wel.jsp request.getRequestDispatcher(wel.jsp).forward(request,response); else request.getRequestDispatc

11、her(lonin.jsp).forward(request,response); public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException /合二為一this.doGet(request,response);UserListServlet.javapackage com.li.controller;import java.io.IOException;import java.io.PrintWriter;import java

12、.util.ArrayList;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import com.li.model.*;public class UsersListServlet extends HttpServlet /* * The doGet method of the servlet. * * Thi

13、s method is called when a form has its tag value method equals to get. * * param request the request send by the client to the server * param response the response send by the server to the client * throws ServletException if an error occurred * throws IOException if an error occurred */public void

14、doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException tryUserBeanDao ubdao=new UserBeanDao();/在跳轉(zhuǎn)到wel.jsp ArrayList al=ubdao.getUserList(); request.setAttribute(result, al);/重新跳轉(zhuǎn)wel request.getRequestDispatcher(UserList.jsp).forward(request,response); catch(Exce