LoginActivity

Class.forName("oracle.jdbc.driver.OracleDriver");

			Connection con = DriverManager.getConnection( "jdbc:oracle:thin:@localhost:1521:XE" , "system" , "connect" );

			String userName = request.getParameter("userName");
			String password = request.getParameter("password");

			PreparedStatement ps = con.prepareStatement("select * from table where username ="+userName+"and password ="+password);
			ResultSet rs = ps.executeQuery();
			if(rs.next())
			{
				System.out.println("account exists");

				ServletContext ctx = getServletContext();
			}