Java tutorial
import java.io.IOException; import java.io.PrintWriter; import java.net.InetAddress; import java.net.UnknownHostException; import javax.servlet.GenericServlet; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; public class GetKey extends GenericServlet { public void service(ServletRequest req, ServletResponse res) throws ServletException, IOException { res.setContentType("text/plain"); PrintWriter out = res.getWriter(); String key = getInitParameter("key"); String host = req.getServerName(); int port = req.getServerPort(); if (!keyFitsServer(key, host, port)) { out.println("Pirated!"); } else { out.println("Valid"); } } private boolean keyFitsServer(String key, String host, int port) { return true; } }