Beispiel: HTTP-Server mit CGI

class HttpServer

public class HttpServer extends Thread
{
 protected String Docroot;  // Root des Server-Dateisystems
 protected String Index = "index.html";
 protected String CgiProg;  // Cgi-Interpreter
 protected String CgiDir;  // Verzeichnis der Cgi-Dateisystems
 protected ServerSocket Socket; // Die Socket des Servers
 
 public HttpServer(String docroot, String index, int port,
  String cgiprog, String cgidir) throws IOException
 {
  Docroot = docroot;
  CgiProg = cgiprog;
  CgiDir = cgidir;
  Index = index;
  Socket = new ServerSocket(port); // Erzeugen der Socket
 }
 
// Warten auf Requests
 public void run()
 {
  while (true)
  { // Endlos auf Verbindungen warten ...
   while (activeCount() > 100);
    // max. 100 Threads starten, geg. warten
   try
   {
    new HttpHandler(this, Socket.accept()).start();
     // fuer jede Verbindung ein neuer Thread
   }
   catch (IOException e)
   { // Ganz gleich welcher Fehler ...
     System.err.println("Exception: " + e );
   }
  }
 }
 
 static public String GuessContentType(String name)
 { // erraet den MIME-Type anhand der Extension
  if (name.endsWith(".html") || name.endsWith(".htm")) return "text/html";
  else if (name.endsWith(".txt") || name.endsWith(".java")) return "text/plain";
  else if (name.endsWith(".gif")) return "image/gif";
  else if (name.endsWith(".class")) return "application/octet-stream";
  else if (name.endsWith(".jpg") || name.endsWith(".jpeg")) return "image/jpeg";
  else return "text/plain";
 }
 
 static public boolean IsCgi(String name)
 {
  return  (name.endsWith(".cgi"));
 }
 
 public String Translate(String name)
 {
  if (name.endsWith("/")) // evt. Indexfile anhaengen
   name += Index;
  if (IsCgi(name))
   return CgiDir + name;
  else
   return Docroot + name;
 }
 
 public Process CallCgi(String cgi, String[] env) throws IOException
 {
  return Runtime.getRuntime().exec(CgiProg + " " + cgi, env);
 }
 
}