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Java connect to ports in list and return banner

Hi

How can I connect to a list of ports, note if the port is open or closed and if open read a server banner if one is there?

i have tried the code below, it works basically, but if a port is open it takes ages until it goes to the next port.

try {
                                InetAddress address = InetAddress.getByName(domain);
                                int[] ports = new int[]{21, 22, 23, 80, 81, 88, 8080, 443};
                                for (int i = 0; i < ports.length; i++) {
                                    int port = ports[i];
                                    Socket socket = null;
                                    try {
                                        socket = new Socket(address, port);
                                        socket.setSoTimeout(500);
                                        System.out.println("port " + port + " open");
                                        BufferedReader reader = new BufferedReader(
                                                new InputStreamReader(socket.getInputStream()));
                                        String line = reader.readLine();
                                        if (line != null) {
                                            System.out.println(line);
                                        }
                                        socket.close();
                                    } catch (SocketTimeoutException ex) {
                                        // port was open but nothing was read from input stream
                                        //ex.printStackTrace();
                                        System.out.println("error timeout socket: " + port);
                                    } catch (ConnectException ex) {
                                        // port is closed
                                        //ex.printStackTrace();
                                        System.out.println("error socket: " + port);
                                    } catch (IOException e) {
                                        //e.printStackTrace();
                                        System.out.println("error io socket: " + port);
                                    } finally {
                                        if (socket != null && !socket.isClosed()) {
                                            try {
                                                socket.close();
                                            } catch (Exception e) {
                                                e.printStackTrace();
                                                System.out.println("error  socket close: " + port);
                                            }
                                        }
                                    }
                                }

                            } catch (Exception ex) {
                                //NewJFrame.showMessageDialog(null, ex.getMessage(),"Error");
                                System.out.println(">>>> error:" + ex.getMessage() + " " + ex.getStackTrace());
                            }

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Thanks

CEHJ

This is a good place in which to use multithreading. See

http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ExecutorService.html#invokeAll(java.util.Collection,%20long,%20java.util.concurrent.TimeUnit)

Don't use plain Sockets though - you'll get all the headers too, which you presumably don't want? Use URLConnection

netslt

ASKER

I want all banners, I think they are the headers, ie

port 21 open
220 Webland FTP Server v3.10.0 (Build 2) ready...

port 21 open
220 FTP Server ready.

etc.

I think the socket stays open to long with my code, it can take a minute or so until the next loop will be called.

So how can the stream reader be closed faster? Before the socket sends a timeout?

Thanks

ASKER CERTIFIED SOLUTION

CEHJ

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CEHJ