Using Java, you can easily find out what Web server is installed on a remote machine. Just open a URLConnection to the remote host and parse the header for the “Server” entity, which will give the name of the Web server.
//pass the site address as command line argument//eg:- java http://www.javasoft.comimport java.io.*;import java.net.*;public class findServer{ public static void main(String a[]) { try { URL u=new URL(a[0]); System.out.println("Web server of site"+a[0]+"is -"+u.openConnection().getHeaderField("Server")); } catch(Exception e) { System.out.println(e); } }}