try{
    Class.forName("com.mysql.jdbc.Driver");
    con=DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/vaishnavi","root","atreyasa");

    name=request.getParameter("username");
    password=request.getParameter("password");

    st=con.createStatement();
    st1=con.createStatement();

    rs=st.executeQuery("select * from admins where username='"+name+"' and password='"+password+"'");
    rs1=st1.executeQuery("select * from admins where username='"+name+"' and password!='"+password+"'");

    if(rs!=null&&rs.next()){
        session.setAttribute("username",name);
        response.sendRedirect("http://127.0.0.1:8080/Project_programs/home.jsp");
    }
    else if(rs1!=null&&rs.next()){
        out.println("Enter correct password");
    }
    else{
    response.sendRedirect("http://127.0.0.1:8080/Project_programs/register.jsp");
    }
}
catch(Exception e){
    out.println(e);
}

out.println("<h1 align=center>Welcome "+session.getAttribute("username")+"</h1>");