See the Tutorial List

Login System in Servlet

In this example we will show you how to develop a login form using servlet. Here we are using MySql database. List of file to be created are:

  • index.html
  • Login.java
  • Validate.java
  • Welcome.java
  • web.xml

login form example with Servlet

To try this application you will need to create a table in your database and enter some record into it. Refer the previos Lesson for creating table.


index.html

<html>
    <head>
        <title>login form</title>
    </head>
    <body>
        <form method="post" action="login">
        Email ID:<input type="text" name="email" /><br/>
        Password:<input type="text" name="pass" /><br/>
        <input type="submit" value="login" />
        </form>
    </body>
</html>

Login.java

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.sql.*;

public class Login extends HttpServlet {
 
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();
        
        String email = request.getParameter("email");
        String pass = request.getParameter("pass");
        
        if(Validate.checkUser(email, pass))
        {
            RequestDispatcher rs = request.getRequestDispatcher("Welcome");
            rs.forward(request, response);
        }
        else
        {
           out.println("Username or Password incorrect");
           RequestDispatcher rs = request.getRequestDispatcher("index.html");
           rs.include(request, response);
        }
    }  
}

Validate.java

import java.sql.*;

public class Validate {
    public static boolean checkUser(String email,String pass) 
    {
        boolean st =false;
        try {

            //loading drivers for mysql
            Class.forName("com.mysql.jdbc.Driver");

            //creating connection with the database
            Connection con = DriverManager.getConnection("jdbc:mysql:/ /localhost:3306/test","root","studytonight");
            PreparedStatement ps = con.prepareStatement("select * from register where email=? and pass=?");
            ps.setString(1, email);
            ps.setString(2, pass);
            ResultSet rs =ps.executeQuery();
            st = rs.next();

        }
        catch(Exception e) {
            e.printStackTrace();
        }
        return st;                 
    }   
}

Welcome.java

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.sql.*;

public class Welcome extends HttpServlet {

    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();
        out.println("Welcome user");
      }  
}

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0" 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_3_0.xsd" >

    <servlet>
        <servlet-name>login</servlet-name>
        <servlet-class>Login</servlet-class>
    </servlet>
    <servlet>
        <servlet-name>Welcome</servlet-name>
        <servlet-class>Welcome</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>login</servlet-name>
        <url-pattern>/login</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>Welcome</servlet-name>
        <url-pattern>/Welcome</url-pattern>
    </servlet-mapping>
    
</web-app>