用户登录验证MVC模式

1、 模式的用户登录验证系统基于MVC 项目文件结构：一、 视图部分二、ViewLogin.jsp 用户登录 用户名: 密  码: 登录 =獜扵業屴 value=type = input type牜獥瑥 value body/ LoginCL.jsp Wel.jsp headhead 登陆成功！恭喜你！ 重新登陆 显示所有用户列表 UserList.jsp 用户信息列表 用户ID用户名用户密码用户级别 % for(int i=0;i 三、Model模型部分 UserBean.java package .li.model; public class UserBean privat

2、e int userId; private String username; private String passwd; 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

3、 getPasswd() return passwd; public void setPasswd(String passwd) this.passwd = passwd; public int getGrade() return grade; public void setGrade(int grade) = grade; grade.this UserBeanDao.java package .li.model; import java.sql.*; import java.util.*; public class UserBeanDao private Statement sm = nu

4、ll; private ResultSet rs = null; private Connection ct = null; private int pageCount = 0; private int rowCount = 0; private int pageSize = 3; public void close() / 关闭各种打开的资源 try if (rs != null) rs.close(); rs = null; if (sm != null) sm.close(); sm = null; if (ct != null) ct.close(); ct = null; catch

5、 (Exception e) e.printStackTrace();/ 打印异常，以便修改 public ArrayList getUserList() ArrayList 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.setUsernam

6、e(rs.getString(2); ub.setPasswd(rs.getString(3); ub.setGrade(rs.getInt(4); al.add(ub); / 将al放到 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();/ 获取ConnDB中的方法，操作数据库 sm

7、 = ct.createStatement(); rs = sm.executeQuery(select passwd from users where username= + u + ); if (rs.next() if (rs.getString(1).equals(p) b = true; catch (Exception e) e.printStackTrace(); finally / 关闭各种打开的资源，释放存 this.close(); return b; ConnDB.java package .li.model; import java.sql.*; public clas

8、s ConnDB private Connection ct=null; public Connection getConn() try Class.forName(獜湵樮扤?摯换?扤佣扤?楲敶屲); ct=DriverManager.getConnection(橜扤?摯换町敳獲); catch(Exception e) e.printStackTrace(); ; ct return 四、Controller部分 LoginCheckServlet.java package .li.controller; import java.io.IOException; import java.io.

9、PrintWriter; import java.util.ArrayList; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import .li.model.*; public class LoginCheckServlet extends HttpServlet public void doGet

10、(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException /得到用户名和密码 String u=request.getParameter(%username); String p=request.getParameter(passwd); /使用模型，完成验证 UserBeanDao ubdao=new UserBeanDao(); request.setAttribute(%uname, u); if(ubdao.checkUser(u, p) /在跳转到we

11、l.jsp request.getRequestDispatcher(wel.jsp).forward(request,response); else request.getRequestDispatcher(lonin.jsp).forward(request,response); public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException /合二为一 this.doGet(request,response); UserLis

12、tServlet.java package .li.controller; import java.io.IOException; import java.io.PrintWriter; import java.util.ArrayList; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import

13、.li.model.*; public class UsersListServlet extends HttpServlet /* * The doGet method of the servlet. * * This 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 cl

14、ient * throws ServletException if an error occurred * throws IOException if an error occurred */ public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException try UserBeanDao ubdao=new UserBeanDao(); /在跳转到wel.jsp ArrayList al=ubdao.getUserList(); request.setAttribute(esult, al); / 重新跳转wel request.getRequestDispatcher(UserList