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>
