redirecting a login authenticated form to a form to be displayed on the same page from where the login authentication has taken place.

I am successfully able to create a session on successful login, but I want to display the welcome page on the parent page itself instead of getting redirected to welcome.jsp,whisch is a different page altogether.

Please Help Urgently.

View Answers

June 1, 2012 at 5:14 PM

The given code accepts username and password from the user and check whether the user is valid. If user is valid, welcome message will get displayed. Otherwise, the login will get redirected again.

1)login.jsp:

<html>
<script>
function validate(){
var username=document.form.user.value;
var password=document.form.pass.value;
if(username==""){
 alert("Enter Username!");
  return false;
}
if(password==""){
 alert("Enter Password!");
  return false;
}
return true;
}
</script>
<form name="form" method="post" action="http://localhost:8080/examples/Login" onsubmit="javascript:return validate();">
<table>
<tr><td>Username:</td><td><input type="text" name="user"></td></tr>
<tr><td>Password:</td><td><input type="password" name="pass"></td></tr>
<tr><td></td><td><input type="submit" value="Submit"></td></tr>
</table>
</form>
</html>

2)Login.java:

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

public class Login extends javax.servlet.http.HttpServlet implements javax.servlet.Servlet { 

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    try{
        response.setContentType("text/html");
        PrintWriter out=response.getWriter();
        String user=request.getParameter("user");
String pass=request.getParameter("pass");
 Class.forName("com.mysql.jdbc.Driver").newInstance();
    Connection con=DriverManager.getConnection("jdbc:mysql://localhost:3306/test","root","root");  
           Statement st=con.createStatement();
           ResultSet rs=st.executeQuery("select * from login where username='"+user+"' and password='"+pass+"'");
int count=0;
          while(rs.next())
          {

                   count++;
          }

                    if(count>0)
          {
            out.println("welcome "+user);
          }
          else
          {
                       response.sendRedirect("/examples/jsp/login.jsp");
          }
    }
    catch (Exception e) {
    e.printStackTrace();
    }
}
}

June 1, 2012 at 5:16 PM

The given code accepts username and password from the user and check whether the user is valid. If user is valid, welcome message will get displayed. Otherwise, the login page will get redirected again with error message.

1)login.jsp:

<html>
<script>
function validate(){
var username=document.form.user.value;
var password=document.form.pass.value;
if(username==""){
 alert("Enter Username!");
  return false;
}
if(password==""){
 alert("Enter Password!");
  return false;
}
return true;
}
</script>
<form name="form" method="post" action="check.jsp" onsubmit="javascript:return validate();">
<table>
<tr><td>Username:</td><td><input type="text" name="user"></td></tr>
<tr><td>Password:</td><td><input type="password" name="pass"></td></tr>
<tr><td></td><td><input type="submit" value="Submit"></td></tr>
</table>
</form>
</html>
<%String msg=request.getParameter("msg");
if(msg!=null){
    %>
<label><font color="red"><%=msg%></font></label> 
<%
}
    %>

2)check.jsp:

<%@page import="java.sql.*"%>

<%
String user=request.getParameter("user");
String pass=request.getParameter("pass");
 Class.forName("com.mysql.jdbc.Driver").newInstance();
    Connection con=DriverManager.getConnection("jdbc:mysql://localhost:3306/test","root","root");  
           Statement st=con.createStatement();
           ResultSet rs=st.executeQuery("select * from login where username='"+user+"' and password='"+pass+"'");
int count=0;
          while(rs.next())
          {

                   count++;
          }

                    if(count>0)
          {
            out.println("welcome "+user);
          }
          else
          {
                       response.sendRedirect("login.jsp?msg=Invalid Username or Password");
          }
%>

June 1, 2012 at 5:17 PM

You can also visit the following links:

http://www.roseindia.net/jsp/loginbean.shtml

http://www.roseindia.net/quickguide/tomcat/Logout.shtml

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