基于MVC 用户登录的实现（JavaBean + Servlet + JSP)

1、web.xml配置

<?xml version=”1.0″ encoding=”UTF-8″?>
<web-app version=”2.5″
xmlns=”http://java.sun.com/xml/ns/javaee”
xmlns:xsi=”http://www.w3.org/2001/XMLSchema-instance”
xsi:schemaLocation=”http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd”>
<welcome-file-list>
<welcome-file>login.jsp</welcome-file>
</welcome-file-list>

<servlet>
<servlet-name>loginServlet</servlet-name>
<servlet-class>org.zxj.mvcdemo.servlet.LoginServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>loginServlet</servlet-name>
<url-pattern>/LoginServlet</url-pattern>
</servlet-mapping>
</web-app>

 

2、User

 

package org.zxj.mvcdemo.vo;

public class User{
private String userid;
private String name;
private String password;
public void setUSerid(String userid){
this.userid = userid;
}
public void setName (String name){
this.name = name;
}
public void setPassword(String password){
this.password = password;
}
public String getUserid(){
return this.userid;
}
public String getName(){
return this.name;
}
public String getPassword(){
return this.password;
}

}

 

3、DatabaseConnection

 

package org.zxj.mvcdemo.dbc;

import java.sql.*;

public class DatabaseConnection{

private static final String DBDRIVER = “com.mysql.jdbc.Driver”;
private static final String DBURL = “jdbc:mysql://localhost:3306/zxj”;
private static final String DBUSER = “root”;
private static final String DBPASSWORD =”pf”;
private static Connection con = null;
public DatabaseConnection() throws Exception{
try{
Class.forName(DBDRIVER);
this.con = DriverManager.getConnection(DBURL,DBUSER,DBPASSWORD);
}catch(Exception e){
throw e;
}
}
public Connection getConnection(){
return this.con;
}
public void close() throws Exception {
if(this.con != null){
try{
this.con.close();
}catch(Exception e){
throw e;
}
}
}
}

 

4、IUserDAO

 

package org.zxj.mvcdemo.dao;

import org.zxj.mvcdemo.vo.User;

public interface IUserDAO{
public boolean findLogin(User user) throws Exception;
}

 

5、UserDAOImpl

 

package org.zxj.mvcdemo.dao.impl;

import org.zxj.mvcdemo.vo.User;
import org.zxj.mvcdemo.dao.*;
import java.sql.*;

public class UserDAOImpl implements IUserDAO{
private Connection conn = null;
private PreparedStatement pstmt = null;
public UserDAOImpl(Connection conn){
this.conn = conn;
}
public boolean findLogin(User user) throws Exception{
boolean flag = false;
String sql = “select name from user where userid= ? and password = ?”;
this.pstmt = this.conn.prepareStatement(sql);
this.pstmt.setString(1,user.getUserid());
this.pstmt.setString(2,user.getPassword());
ResultSet rs = this.pstmt.executeQuery();
if(rs.next()){
user.setName(rs.getString(“name”));
flag = true;
}
this.pstmt.close();
return flag;
}
}

 

6、UserDAOProxy

 

package org.zxj.mvcdemo.dao.proxy;

import org.zxj.mvcdemo.vo.User;
import org.zxj.mvcdemo.dbc.*;
import org.zxj.mvcdemo.dao.*;
import org.zxj.mvcdemo.dao.impl.*;
import java.sql.*;

public class UserDAOProxy implements IUserDAO{
private DatabaseConnection dbc = null;
private IUserDAO dao = null;
private PreparedStatement pstmt = null;
public UserDAOProxy(){
try{
this.dbc = new DatabaseConnection();
}catch(Exception e){
e.printStackTrace();
}
this.dao = new UserDAOImpl(dbc.getConnection());
}
public boolean findLogin(User user) throws Exception{
boolean flag = false;
try{
flag = this.dao.findLogin(user);
}catch(Exception e){
throw e;
}finally{
this.dbc.close();
}
return flag;
}
}

 

7、DAOFactory

 

 

package org.zxj.mvcdemo.factory;

import org.zxj.mvcdemo.dao.*;
import org.zxj.mvcdemo.dao.proxy.*;
public class DAOFactory{
public static IUserDAO getIUserDAOInstance(){
return new UserDAOProxy();
}
}

 

8、LoginServlet

package org.zxj.mvcdemo.servlet;

import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
import org.zxj.mvcdemo.factory.*;
import org.zxj.mvcdemo.vo.*;

public class LoginServlet extends HttpServlet{
public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,IOException {
String path = “login.jsp”;
String userid = req.getParameter(“userid”);
String userpass = req.getParameter(“userpass”);
List<String> info = new ArrayList<String>();
if(userid == null || “”.equals(userid)){
info.add(“用户id不能为空”);
}
if(userpass == null || “”.equals(userpass)){
info.add(“密码不能为空”);
}
if(info.size() == 0){
User user = new User();
user.setUSerid(userid);
user.setPassword(userpass);
try{
if(DAOFactory.getIUserDAOInstance().findLogin(user)){
info.add(“用户登录成功，欢迎”+user.getName()+ “登录”);
}else{
info.add(“用户登录失败”);
}
}catch(Exception e){
e.printStackTrace();
}
}
req.setAttribute(“info”,info);
req.getRequestDispatcher(path).forward(req,res);
//RequestDispatcher rd = null;
//rd = req.getRequestDispatcher(path);
//rd.forward(req,res);

}
public void doPost(HttpServletRequest req, HttpServletResponse res) throws ServletException,IOException {
doGet(req,res);
}
}

 

9、Login.jsp

 

 

 

<%@ page language=”java” contentType=”text/html” pageEncoding=”GBK” %>
<%@ page import=”java.util.*”%>
<html>
<head>
<title>登录</title>
<meta http-equiv=”content-type” content=”text/html;charset=gbk”>
</head>

<body>
<%
request.setCharacterEncoding(“GBK”);
List<String> info = (List<String>)request.getAttribute(“info”);
if(info != null){
Iterator<String> iter = info.iterator();
while(iter.hasNext()){
out.println(iter.next());
}
}
%>
<form action=”LoginServlet” method=”post”>
用户：<input type=”text” name=”userid” /> <br />
密码：<input type=”password” name=”userpass” /><br />
<input type=”submit” value=”登录” />
<input type=”reset” value=”重置” />
</body
</html>