关于MVC模式的登录注册

 1 package com.util; 2 ?3 import java.sql.Connection; 4 import java.sql.DriverManager; 5 import java.sql.SQLException; 6 ?7 public class DbUtil { 8 ?????9 ????private String url="jdbc:mysql://localhost:3306/test";10 ????private String user="root";11 ????private String password="root";12 ????private String driver="com.mysql.jdbc.Driver";13 ????14 ????public Connection getCon() throws Exception{15 ????????Class.forName(driver);16 ????????Connection con=DriverManager.getConnection(url, user, password);17 ????????return con;18 ????}19 ????20 ????public static void getClose(Connection con) throws SQLException{21 ????????if(con!=null){22 ????????????con.close();23 ????????}24 ????}25 ????26 ????/*public static void main(String[] args) {27 ????????DbUtil db=new DbUtil();28 ????????try {29 ????????????db.getCon();30 ????????????System.out.println("测试连接数据库，连接成功");31 ????????} catch (Exception e) {32 ????????????// TODO Auto-generated catch block33 ????????????e.printStackTrace();34 ????????????System.out.println("测试连接数据库，连接失败");35 ????????}36 ????????37 ????}*/38 }

 1 package com.model; 2 ?3 import java.sql.DriverManager; 4 ?5 import com.mysql.jdbc.Connection; 6 import com.mysql.jdbc.PreparedStatement; 7 ?8 public class User { 9 10 ????private int id;11 ????private String username;12 ????private String password;13 ????14 ????15 ????public User() {16 ????????super();17 ????}18 ????public User(String username, String password) {19 ????????super();20 ????????this.username = username;21 ????????this.password = password;22 ????}23 ????public int getId() {24 ????????return id;25 ????}26 ????public void setId(int id) {27 ????????this.id = id;28 ????}29 ????public String getUsername() {30 ????????return username;31 ????}32 ????public void setUsername(String username) {33 ????????this.username = username;34 ????}35 ????public String getPassword() {36 ????????return password;37 ????}38 ????public void setPassword(String password) {39 ????????this.password = password;40 ????}41 ????42 43 }

 ?1 package com.dao; ?2 ??3 import java.sql.Connection; ?4 import java.sql.PreparedStatement; ?5 import java.sql.ResultSet; ?6 import java.sql.SQLException; ?7 ??8 ??9 import com.ningmeng.model.User; 10 ?11 public class UserDao { 12 ?????13 ????public User login(Connection con,User user) throws SQLException{ 14 ????????User resultUser=null; 15 ????????String sql="select * from user where name=? and password=?"; 16 ????????PreparedStatement ps=con.prepareStatement(sql);// 17 ????????ps.setString(1, user.getUsername()); 18 ????????ps.setString(2, user.getPassword()); 19 ????????ResultSet rs=ps.executeQuery(); 20 ????????if(rs.next()){ 21 ????????????resultUser=new User(); 22 ????????????resultUser.setUsername(rs.getString("name")); 23 ????????????resultUser.setPassword(rs.getString("password")); 24 ????????} 25 ????????return resultUser; 26 ????} 27 ????public boolean insert(Connection con,User user) 28 ????{ 29 ????????String sql = "INSERT INTO user(name,password) VALUES (?,?)"; ?//添加的SQL语句 30 ?????????boolean flag=false; ??31 ?????????try{ ??32 ?????????????PreparedStatement psta=con.prepareStatement(sql);// ?33 ?????????????psta.setString(1, user.getUsername()); ??34 ?????????????psta.setString(2, user.getPassword()); ??35 ?????????????flag=psta.executeUpdate()>0; 36 ?????????}catch(Exception e){ ??37 ?????????????e.printStackTrace(); ??38 ?????????} 39 ?????????????try { 40 ????????????????con.close(); 41 ????????????} catch (SQLException e) { 42 ?????????????????43 ????????????????e.printStackTrace(); 44 ????????????} 45 ?????????????return flag; ??????46 ????} 47 ?????48 ????//通过id查找 ??49 ????public User selectById(Connection con,int id){ ??50 ??????????51 ????????PreparedStatement psta=null; ??52 ????????ResultSet rs=null; ??53 ????????User user=null; ??54 ????????String sql="select * from user where id=?"; ??55 ????????try{ ??56 ????????????psta=con.prepareStatement(sql); ??57 ????????????psta.setInt(1, id); ??58 ????????????rs=psta.executeQuery(); ??59 ????????????if(rs.next()){ ??60 ????????????????user=new User(); ??61 ????????????????user.setId(rs.getInt(1)); ??62 ????????????????user.setUsername(rs.getString(2)); ??63 ????????????????user.setPassword(rs.getString(3)); ??64 ?65 ????????????} ??66 ????????}catch(Exception e){ ??67 ????????????e.printStackTrace(); ??68 ????????} ?69 ????????????try{ ??70 ????????????????con.close(); ??71 ????????????}catch(Exception e){ ??72 ????????????????e.printStackTrace(); ??73 ????????????} ??74 ????????????return user; ????75 ????} 76 ??//更新方法（修改数据）（改） ??77 ????public boolean update(Connection con,User user){ ??78 ????????PreparedStatement psta=null; ??79 ????????String sql="update user set name=?,password=? where id=?"; ??80 ????????boolean flag=false; ??81 ????????try{ ??82 ????????????psta=con.prepareStatement(sql); ??83 ????????????psta.setString(1, user.getUsername()); ??84 ????????????psta.setString(2, user.getPassword()); ???85 ????????????psta.setInt(3,user.getId()); ??86 ????????????flag=psta.executeUpdate()>0; ??87 ????????}catch(Exception e){ ??88 ????????????e.printStackTrace(); ??89 ????????} 90 ????????????try{ ??91 ????????????????con.close(); ??92 ????????????}catch(Exception e){ ??93 ????????????????e.printStackTrace(); ??94 ????????????} ??95 ????????????return flag; ??96 ????} ?97 ?????98 ????public boolean deleteAdmin(Connection con,int id){ ?//删除 99 ????????String sql = "delete from user where id = ?"; ?//删除的SQL语句，根据ID删除100 ????????try {101 ????????????PreparedStatement pst = con.prepareStatement(sql);102 ????????????pst.setInt(1, id);103 ????????????int count = pst.executeUpdate();104 ????????????pst.close();105 ????????????return count>0?true:false; ?//是否删除的判断106 ????????} catch (SQLException e) {107 ????????????e.printStackTrace();108 ????????}109 ????????return false;110 ????}111 ????112 }

 1 package com.web; 2 ?3 import java.io.IOException; 4 import java.sql.Connection; 5 ?6 import javax.servlet.ServletException; 7 import javax.servlet.http.HttpServlet; 8 import javax.servlet.http.HttpServletRequest; 9 import javax.servlet.http.HttpServletResponse;10 import javax.servlet.http.HttpSession;11 12 import com.ningmeng.dao.UserDao;13 import com.ningmeng.model.User;14 import com.ningmeng.util.DbUtil;15 16 public class LoginServlet extends HttpServlet{17 18 ????DbUtil db=new DbUtil();19 ????UserDao userDao=new UserDao();20 ????/**21 ?????* 22 ?????*/23 ????private static final long serialVersionUID = 1L;24 25 ????@Override26 ????protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {27 ????????this.doPost(request, response);28 ????}29 30 ????@Override31 ????protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {32 ????????String username=request.getParameter("username");33 ????????String password=request.getParameter("password");34 ????????Connection con=null;35 ????????try {36 ????????????User user=new User(username,password);37 ????????????con=db.getCon();38 ????????????User currentUser=userDao.login(con, user);39 ????????????if(currentUser==null){40 ????????????????//System.out.println("no");41 ????????????????request.setAttribute("error", "用户名或者密码错误");42 ????????????????request.setAttribute("username", username);43 ????????????????request.setAttribute("password", password);44 ????????????????request.getRequestDispatcher("login.jsp").forward(request, response);45 ????????????}else{46 ????????????????//System.out.println("yes");47 ????????????????HttpSession session=request.getSession();48 ????????????????session.setAttribute("currentUser",currentUser);49 ????????????????response.sendRedirect("main.jsp");50 ????????????}51 ????????} catch (Exception e) {52 ????????????// TODO Auto-generated catch block53 ????????????e.printStackTrace();54 ????????}55 ????????56 ????}57 ????58 ????59 }

 1 package com.web; 2 ?3 import java.io.IOException; 4 import java.sql.Connection; 5 ?6 import javax.servlet.ServletException; 7 import javax.servlet.annotation.WebServlet; 8 import javax.servlet.http.HttpServlet; 9 import javax.servlet.http.HttpServletRequest;10 import javax.servlet.http.HttpServletResponse;11 12 import com.ningmeng.dao.UserDao;13 import com.ningmeng.model.User;14 import com.ningmeng.util.DbUtil;15 16 /**17 ?* Servlet implementation class RegistServlet18 ?*/19 @WebServlet("/RegistServlet")20 public class RegistServlet extends HttpServlet {21 ????private static final long serialVersionUID = 1L;22 ???????23 ????DbUtil db=new DbUtil();24 ????UserDao userDao=new UserDao();25 ????/**26 ?????* @see HttpServlet#HttpServlet()27 ?????*/28 ????public RegistServlet() {29 ????????super();30 ????????// TODO Auto-generated constructor stub31 ????}32 33 ????/**34 ?????* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)35 ?????*/36 ????protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {37 ????????String username=request.getParameter("username");38 ????????String password=request.getParameter("password");39 ????????Connection con=null;40 ????????41 ????????User user=new User(username,password);42 ????????try {43 ????????????con=db.getCon();44 ????????} catch (Exception e) {45 ????????????46 ????????????e.printStackTrace();47 ????????}48 ????????boolean current=userDao.insert(con, user);49 ????????System.out.print(current);50 ????????System.out.print(user.getUsername());51 ????????if(current){52 ?????????????request.setAttribute("error", "注册成功");53 ????????????54 ????????}else{55 ?????????????request.setAttribute("error", "注册失败");56 ?????????????request.getRequestDispatcher("Regist.jsp").forward(request, response);57 ????????}58 ????????59 ????}60 61 ????/**62 ?????* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)63 ?????*/64 ????protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {65 ????????// TODO Auto-generated method stub66 ????????doGet(request, response);67 ????}68 69 }

 1 <%@ page language="java" contentType="text/html; charset=gbk" 2 ????pageEncoding="gbk"%> 3 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 4 <html> 5 <head> 6 <meta http-equiv="Content-Type" content="text/html; charset=gbk"> 7 <title>Insert title here</title> 8 </head> 9 <body>10 <form action="login" method="post">11 ?????<table>12 ?????????<tr>13 ?????????????<th colspan="2">登录界面</th>14 ?????????</tr>15 ?????????<tr>16 ?????????????<td>账号</td>17 ?????????????<td><input type="text" id="username" name="username" value="${username}"></td>18 ?????????</tr>19 ?????????<tr>20 ?????????????<td>密码：</td>21 ?????????????<td><input type="text" id="password" name="password" value="${password}"></td>22 ?????????</tr>23 ?????????<tr>24 ?????????????<td><input type="submit" value="提交"></td>25 ?????????????<td><font color="red">${error}</font></td>26 ?????????</tr>27 ?????</table>28 ?</form>29 ?</body>30 </html>

 1 <%@ page language="java" contentType="text/html; charset=gbk" 2 ????pageEncoding="gbk"%> 3 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 4 <html> 5 <head> 6 <meta http-equiv="Content-Type" content="text/html; charset=gbk"> 7 <title>Insert title here</title> 8 </head> 9 <body>10 <form action="login" method="post">11 ?????<table>12 ?????????<tr>13 ?????????????<th colspan="2">注册界面</th>14 ?????????</tr>15 ?????????<tr>16 ?????????????<td>账号</td>17 ?????????????<td><input type="text" id="username" name="username" ></td>18 ?????????</tr>19 ?????????<tr>20 ?????????????<td>密码：</td>21 ?????????????<td><input type="text" id="password" name="password" ></td>22 ?????????</tr>23 ?????????<tr>24 ?????????????<td><input type="submit" value="提交"></td>25 ?????????????<td><font color="red">${error}</font></td>26 ?????????</tr>27 ?????</table>28 ?</form>29 ?</body>30 </html>

 1 <%@ page language="java" contentType="text/html; charset=gbk" 2 ????pageEncoding="gbk"%> 3 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 4 <html> 5 <head> 6 <meta http-equiv="Content-Type" content="text/html; charset=gbk"> 7 <title>Insert title here</title> 8 </head> 9 <body>10 ?<p>登录成功</p>11 ?当前用户：${currentUser.username}<br/>12 ?当前密码：${currentUser.password}<br/>13 ?</body>14 </html>