1.数据库的连接
package Database;
import javax.xml.transform.Result;
import java.sql.*;
public class DbManager {
private Connection conn=null;
private Statement state=null;
private ResultSet rs=null;
private String username="root";
private String password="wzp961208";
private String driver="com.mysql.jdbc.Driver";
private String url="jdbc:mysql://localhost:3306/tt";
public Connection getConnection(){
try {
Class.forName ( driver );
System.out.println ("数据库加载成功" );
conn=DriverManager.getConnection ( url,username,password );
System.out.println ("数据库连接成功" );
} catch (Exception e) {
e.printStackTrace ( );
}
return conn;
}
public int updataNethod(String strsql) {
int flag=0;
try {
conn = this.getConnection ( );
state = conn.createStatement ( );
System.out.println ("数据库的更新" );
flag=state.executeUpdate ( strsql );
}catch (Exception e){
e.printStackTrace ();
}
return flag;
}
public ResultSet queryMethod(String strsql){
try {
conn = this.getConnection ( );
state = conn.createStatement ( );
System.out.println ("数据库的更新" );
rs=state.executeQuery ( strsql );
return rs;
}catch (Exception e){
e.printStackTrace ();
}
return rs;
}
public void closeDB(){
try {
if(rs!=null) {
rs.close ( );
}
if(conn!=null){
conn.close ();
}
if(state!=null){
state.close ();
}
} catch (SQLException e) {
e.printStackTrace ( );
}
}
}
二、页面跳转控制部分
package Servlet;
import VO.UserInfo;
import shujukufangwenceng.UserInforDAO;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
@WebServlet( "/LoginServlet")
public class LoginServlet extends HttpServlet {
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost ( request,response );
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType ( "text/html;charset=UTF-8" );
PrintWriter out=response.getWriter ();
String username=request.getParameter ( "username" );
String password=request.getParameter ( "password" );
UserInfo userInfo=new UserInfo ();
userInfo.setName ( "username" );
userInfo.setPass ( "password" );
UserInforDAO userInforDAO=new UserInforDAO ();
int flag=userInforDAO.checkUserInfo ( userInfo );
if(flag==1){
request.setAttribute ( "userinfo",userInfo );
request.getRequestDispatcher ( "success.jsp" ).forward ( request,response );
}else{
request.getRequestDispatcher ( "failure.jsp" ).forward ( request,response );
}
}
}
三、Java模拟数据库部分
package VO;
public class UserInfo {
private int id;
private String name;
private String pass;
public UserInfo(){}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPass() {
return pass;
}
public void setPass(String pass) {
this.pass = pass;
}
@Override
public String toString() {
return "UserInfo{" +
"id=" + id +
", name='" + name + '\'' +
", pass='" + pass + '\'' +
'}';
}
}
四、Java代码与数据库之间的关系
package shujukufangwenceng;
//检查用户名和密码是否一致
import Database.DbManager;
import VO.UserInfo;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class UserInforDAO {
public int checkUserInfo(UserInfo userInfo){
int flag=0;
String strsql="Select name,pass from t_user where name='"+userInfo.getName ()+"'and pass='"+userInfo.getPass ( )+"'";
try {
DbManager dbManager=new DbManager ();
ResultSet resultSet= dbManager.queryMethod ( strsql );
String name=null;
String pass=null;
while (resultSet.next ()){
name= resultSet.getString ( "name" );
pass= resultSet.getString ( "pass" );
if(name.equals (userInfo.getName () )&&pass.equals ( userInfo.getPass () )){
flag=1;
}else{
flag=0;
}
return flag;
}
} catch (Exception e) {
e.printStackTrace ( );
}
return flag;
}
}
五、Jsp页面
1.login.jsp;
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<form action="LoginServlet" method="post">
username:<input type="text" name="username" ></br>
password:<input type="password" name="password"> </br>
<input type="submit" value="Submit">
<input type="reset" value="Reset">
</form>
</body>
</html>
2.success.jsp;
<%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<font color="red" size="100px">success!</font> ${userinfo.username}
</body>
</html>
3.failure.jsp;
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<font color="red" size="100px">failure!</font>
</body>
</html>
