Javaweb+jdbc+servlet+sqlserver Implementing the Login function

To create the Javaweb project first, you can refer to the following:

51013400

Attached Project structure:

1. Rewrite the contents of the login page index.jsp

<%--Created by IntelliJ idea. User:lxj ' PC date:2018/5/12 time:15:49 To change this template use File | Settings | File templates.--%><%@ page contenttype= "Text/html;charset=utf-8" language= "java"%>Package Org.user.util;import java.sql.*;p ublic class Dbutil {//mysql Drive pack name private static final String driver_name =    "Com.microsoft.sqlserver.jdbc.SQLServerDriver"; Database connection address private static final String URL = "Jdbc:sqlserver://localhost:1433;integratedsecurity=true;databasename=    Javaweb ";    User name private static final String user_name = ".";    Password private static final String PASSWORD = "";            public static Connection getconnection () {try {//load MySQL driver class class.forname (driver_name);        Get the database connection return drivermanager.getconnection (URL);            } catch (Exception e) {e.printstacktrace ();        return null; }} public static void Closeconn (Connection conn,statement stm, ResultSet rs) {if (stm!=null) {TR            y {stm.close ();            } catch (SQLException e) {e.printstacktrace ();       }} if (conn! = null) {try {         Conn.close ();            } catch (SQLException e) {e.printstacktrace ();            }} if (Rs!=null) {try{rs.close ();            }catch (SQLException e) {e.printstacktrace ();    }}} public static void Main (string[] args) {System.out.println (getconnection ()); }}

3. New Entity class user

Package Org.user.entity;public class User {    private String userName;    Private String PassWord;    Public String GetUserName () {        return userName;    }    public void Setusername (String userName) {        this.username = userName;    }    Public String GetPassword () {        return passWord;    }    public void SetPassword (String passWord) {        This.password = PassWord;    }}

4. New Class Userdao

Package Org.user.dao;import Java.sql.*;import Org.user.entity.user;import Org.user.util.dbutil;public class UserDao { Find user public based on username user finduserbyname (string userName) {//write SQL statement string sql= "select * from Login where        Username=? ";        Get Connected Connection conn= dbutil.getconnection ();        There is a return result ResultSet rs= null;        Instantiate a user object user user = new user ();            try {//PreparedStatement PS = conn.preparestatement (SQL) used to send SQL statements;            Set the parameters to pass in, here is Usern ps.setstring (1, userName);            Execute SQL statement rs=ps.executequery (); If you can find the result if (Rs.next ()) {//Then the found result one by one set into the user Object User.setusername (rs.getstring (1))                ;            User.setpassword (rs.getstring (2));        }} catch (SQLException e) {//TODO auto-generated catch block E.printstacktrace (); } finally {//close connection Dbutil.closeConn (Conn, NULL, RS);    }//The user is finally returned to return user;        } public static void Main (string[] args) {Userdao dao = new Userdao ();        User i = dao.finduserbyname ("Lxj");    System.out.println (I.getpassword ()); }}

5. New service class Loginservice

Package Org.user.service;import Org.user.dao.userdao;import Org.user.entity.user;public class LoginService {    public boolean CheckUser (String userName, String passWord) {        Userdao dao = new Userdao ();        User user = Dao.finduserbyname (userName);        SYSTEM.OUT.PRINTLN (user);        return user! = null && password.equals (User.getpassword ())? True:false;}    }

6. New Servlet class Loginservlet

Package Org.user.servlet;import Java.io.ioexception;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 Org.user.dao.UserDao; Import Org.user.entity.user;import Org.user.service.LoginService; @WebServlet (name = "Loginservlet") public class    Loginservlet extends HttpServlet {private static final long serialversionuid = 1L; The Sqljdbc_auth.dll file was placed under the D:\java-jdk8\bin path of this computer, and the unsuccessful login problem protected void service (HttpServletRequest request) was resolved. HttpServletResponse response) throws Servletexception, IOException {//Set encoding request.setcharacterencoding ("UT        F-8 ");        Response.setcharacterencoding ("Utf-8");        Gets the data submitted from the page String userName = Request.getparameter ("UserName");        String Userpass = Request.getparameter ("PassWord");        Loginservice service = new Loginservice (); Call the service method to set the user name secretThe code is passed to service Boolean flag = Service.checkuser (UserName, Userpass); String msg = flag? "        Success ":" Error ";        Request.setattribute ("msg", MSG);        if (msg== "Success") {Request.getrequestdispatcher ("login_success.jsp"). Forward (request, response);        } else{Request.getrequestdispatcher ("login_failure.jsp"). Forward (request, response); }    }}

7. Finally, the new login_success.jsp and login_failure.jsp files in the index.jsp sibling directory are used for login success or failure jump page prompts.

Tip: If a warning appears: Failed to load the Sqljdbc_auth.dll cause:-No sqljdbc_auth in Java.library.path, you can put Sqljdbc_auth.dll The file is placed in the Bin folder in your point JDK directory, for example, the D:\java-jdk8\bin path of my own computer is put into the Sqljdbc_auth.dll file

Javaweb+jdbc+servlet+sqlserver Implementing the Login function