Android Socket Connection with AIS Transponder throws IOException

Question

I am trying to read the AIS serial data on an Android device over WiFi by creating a TCP connection with the AIS Transponder. I am using the EM-Trak B360 AIS transponder and creating a socket on the android device using the following code:

public class Client extends AsyncTask<Void, Void, Void> {

  String dstAddress;
  int dstPort;
  String response = "";
  TextView textResponse;

  Client(String addr, int port, TextView textResponse) {
    dstAddress = addr;
    dstPort = port;
    this.textResponse = textResponse;
  }

  @Override
  protected Void doInBackground(Void... arg0) {

    Socket socket = null;

    try {
      socket = new Socket(dstAddress, dstPort);

      ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream(1024);
      byte[] buffer = new byte[1024];

      int bytesRead;
      InputStream inputStream = socket.getInputStream();

      /*
       * notice: inputStream.read() will block if no data return
       */
      while ((bytesRead = inputStream.read(buffer)) != -1) {
        byteArrayOutputStream.write(buffer, 0, bytesRead);
        response += byteArrayOutputStream.toString("UTF-8");
      }

    } catch (UnknownHostException e) {
      e.printStackTrace();
      response = "UnknownHostException: " + e.toString();
    } catch (IOException e) {
      e.printStackTrace();
      response = "IOException: " + e.toString();
    } finally {
      if (socket != null) {
        try {
          socket.close();
        } catch (IOException e) {
          e.printStackTrace();
        }
      }
    }
    return response;
  }

  @Override
  protected void onPostExecute(Void result) {
    textResponse.setText(response);
    super.onPostExecute(result);
  }

The above code works for mobile-to-mobile connection by creating a mobile hotspot. However when connecting the AIS Transponder's Wifi network it throws the I/O Exception: Software Caused Connection Abort.

08-20 17:04:39.089 13505-13534/com.hfad.slave W/System.err: java.net.SocketException: Software caused connection abort
08-20 17:04:39.090 13505-13534/com.hfad.slave W/System.err:
  at java.net.PlainSocketImpl.socketConnect(Native Method)
  at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:334)
  at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:196)
  at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:178)
  at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:356)
  at java.net.Socket.connect(Socket.java:586)
  at java.net.Socket.connect(Socket.java:535)
  at java.net.Socket.<init>(Socket.java:427)
  at java.net.Socket.<init>(Socket.java:210)
  at com.hfad.slave.Client.doInBackground(Client.java:47)
  at com.hfad.slave.Client.doInBackground(Client.java:16)
  at android.os.AsyncTask$2.call(AsyncTask.java:304)
  at java.util.concurrent.FutureTask.run(FutureTask.java:237)
  at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:243)
  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1133)
  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607)
  at java.lang.Thread.run(Thread.java:762)

`response += byteArrayOutputStream.toString("UTF-8");`. You should put that after the while loop. — greenapps, Aug 20 '18 at 15:33
`The above code works for mobile-to-mobile connection by creating a mobile hotspot.` ??? — greenapps, Aug 20 '18 at 15:46
@greenapps the code is throwing exception while creating the Socket — NadeemGul, Aug 21 '18 at 09:59
@greenapps I mean when running the code on any other Wifi network the above code works. It only breaks when the android device is connected to the Wifi network of an AIS transponder. — NadeemGul, Aug 21 '18 at 10:02

score 0 · Answer 1 · answered Aug 21 '18 at 14:55

0

I got the solution to the problem. I used telnetclient library from Apache Commons. https://commons.apache.org/proper/commons-net/apidocs/org/apache/commons/net/telnet/TelnetClient.html

Now i'm able to communicate with AIS transponder.

Thanks!!

answered Aug 21 '18 at 14:55

NadeemGul

1
2

Android Socket Connection with AIS Transponder throws IOException

1 Answers1