AsyncTask, doInBackground never runs in android

Question

When i try to start my doinbackground to wait for an incoming message it never really run thru it just skips over it

public class Incomingdata extends AsyncTask<Void,Void,Void>
{
    Socket s  ;
    String input;

    public Incomingdata(Socket socket)
    {   
        super();
        this.s = socket;
    }

    @Override
    protected Void doInBackground(Void... params) 
    {
        Log.i("ddd","Got here before try");
        try
        {   
            InputStream in = s.getInputStream();
            Scanner r = new Scanner(in);
            Log.i("Info",s.getPort()+"");
            Log.i("ddd","Got here");
            while(s.isConnected() && r.hasNext())
            {
                String input =r.nextLine(); 
            }
        }
        catch (UnknownHostException e) 
        {
               e.printStackTrace();
        }
        catch (IOException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        catch(NoSuchElementException e)
        {
            e.printStackTrace();
        }
        return null;
    }

    @Override
    protected void onPostExecute(Void input)
    {
        System.out.println("123"+input);
    }

}

And here is my log cat

 java.net.Socket.startupSocket(Socket.java:724)
04-25 23:50:26.659: W/System.err(28882):    at java.net.Socket.<init>(Socket.java:263)
04-25 23:50:26.659: W/System.err(28882):    at com.example.handy.myComs.sending_data(myComs.java:23)
04-25 23:50:26.659: W/System.err(28882):    at com.example.handy.MainActivity.readSms(MainActivity.java:277)
04-25 23:50:26.659: W/System.err(28882):    at com.example.handy.MainActivity$1.onClick(MainActivity.java:92)
04-25 23:50:26.659: W/System.err(28882):    at android.view.View.performClick(View.java:2485)
04-25 23:50:26.659: W/System.err(28882):    at android.view.View$PerformClick.run(View.java:9080)
04-25 23:50:26.659: W/System.err(28882):    at android.os.Handler.handleCallback(Handler.java:587)
04-25 23:50:26.659: W/System.err(28882):    at android.os.Handler.dispatchMessage(Handler.java:92)
04-25 23:50:26.659: W/System.err(28882):    at android.os.Looper.loop(Looper.java:130)
04-25 23:50:26.659: W/System.err(28882):    at android.app.ActivityThread.main(ActivityThread.java:3687)
04-25 23:50:26.659: W/System.err(28882):    at java.lang.reflect.Method.invokeNative(Native Method)
04-25 23:50:26.659: W/System.err(28882):    at java.lang.reflect.Method.invoke(Method.java:507)
04-25 23:50:26.659: W/System.err(28882):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867)
04-25 23:50:26.659: W/System.err(28882):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:625)
04-25 23:50:26.659: W/System.err(28882):    at dalvik.system.NativeStart.main(Native Method)
04-25 23:50:26.729: I/System.out(28882): 123null

This is where i am calling it

public class myComs 
{
    private static int i = 0;

    public static void sending_data(String ipAddress, String message)
    {
        try
        {
            InetAddress inet = InetAddress.getByName(ipAddress);
            Socket s = new Socket(inet, 2000);
            OutputStream o = s.getOutputStream();
            PrintWriter p = new PrintWriter(o);
            while(i<1)
            {
                new Incomingdata(s).execute();
                i++;
            }
            p.println(message);
            p.flush();
        }
        catch (UnknownHostException e)
        {
            e.printStackTrace();
        }
        catch (IOException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

As you can see by the 123null it never waits any help would be great as i am at this with ages and getting no where fast

Thank you

UPDATE Right i got going thru and know its getting the port and but its still not waiting for incoming data its just finishing

Looks like your code fails before you even call the AsyncTask. `at com.example.handy.myComs.sending_data(myComs.java:23)` when you create the Socket. — SimonSays, Apr 25 '13 at 23:10
you see the thing is i dont create the socket there and it always seem to throw a warning there every before i tried to this ASYNCTASK. The program was doing everything i asked it too like it was suppose too — Paul Pandaboy Dennehy, Apr 25 '13 at 23:11
@PaulPandaboyDennehy Try to use `System.out.println("Got here before try");` in that line. If it shows, everything should make sense. — wtsang02, Apr 25 '13 at 23:16
please check if your `InetAddress` object is created properly. Furthermore, Asynctask instance need to be created on UI thread. Are you doing that? — minhaz, Apr 25 '13 at 23:17
InetAddress is being created correctly but the AsyncTask is not being created on the main UI — Paul Pandaboy Dennehy, Apr 25 '13 at 23:44
What if you moved the `OutputStream o = s.getOutputStream(); PrintWriter p = new PrintWriter(o);` into the actual `doInBackground`, I suspect there's a blocking in there? What does line 23 actually say from the logcat `at com.example.handy.myComs.sending_data(myComs.java:23)`? **pro-tip** Please format your code to make it easier for us to read! :) — t0mm13b, Apr 26 '13 at 00:26

score 0 · Answer 1 · answered Apr 25 '13 at 23:14

0

I notice that you are using

System.out.println("123"+input);

for one type of debug, and Log.i for the others. Perhaps it is working, but you're logging view is not set up properly to see Log.i.

If you use a System.out instead of Log.i, can you see the other messages?

answered Apr 25 '13 at 23:14

HalR

11,411
5
48
80

Sorry just tired it there and it still goes straight too System.out.println("123"+input); and never even enters the try doInBackground – Paul Pandaboy Dennehy Apr 25 '13 at 23:18
You changed this line? Log.i("ddd","Got here before try"); to System.out.println("Got here before try") ? – HalR Apr 25 '13 at 23:23
yes i did and still nothing it still went straight to System.out.println("123"+input); – Paul Pandaboy Dennehy Apr 25 '13 at 23:40

score 0 · Answer 2 · edited May 23 '17 at 11:43

0

Are you using more than one asynctask at same time? Because your code seems to be ok. The Async Task model is changed after 2.3 and it disables them to run parallelly. Please check this and this SO question.

edited May 23 '17 at 11:43

Community

1
1

answered Apr 26 '13 at 04:35

Parvaz Bhaskar

1,367
9
29

Yes i am running 2.3.5 but no i am only trying to run one AsyncTask and that is to make the socket wait and listen for incoming data – Paul Pandaboy Dennehy Apr 26 '13 at 08:16

score 0 · Accepted Answer · answered Apr 26 '13 at 15:59

My Problem was that i was creating the socket too many times like a muppet so i had to just create the socket once and then call it use numerous times and now it seems to work like a charm

This is my Asynctask

public class Incomingdata extends AsyncTask<Void,Void,String>
{

    Socket s  ;
    String input;

    public Incomingdata(Socket socket)
    {   
        super();
        this.s = socket;


    }





    @Override
    protected String doInBackground(Void... params) 
    {Log.i("ddd","Got here before try");
        try
        {   System.out.println("Got here");
            InputStream in = s.getInputStream();
            Scanner r = new Scanner(in);
            Log.i("Info",s.getPort()+"");
            Log.i("ddd","Got here");        

            input =r.nextLine();    


        }
        catch (UnknownHostException e) 
        {

               e.printStackTrace();
        }
        catch (IOException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        catch(NoSuchElementException e)
        {
            e.printStackTrace();
        }
        return input ;
    }

    @Override
    protected void onPostExecute(String input)
    {

        String number = input.substring(0, 21).trim();
        String message = input.substring(20);
        System.out.println(""+input);
        sendSMS(number,message);
        new Incomingdata(s).execute();

    }

This is where i am creating the socket

    public class myComs
{
    private static int i = 0;
    private static InetAddress inet;
    private static Socket s;
    private static OutputStream o;
    private static PrintWriter p;

    public static void createSocket(String ipAddress)
    {
        try
        {
            inet = InetAddress.getByName(ipAddress);

            s = new Socket(inet, 2000);
            o = s.getOutputStream();
            p = new PrintWriter(o);
            new Incomingdata(s).execute();
        }
        catch (Exception e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }

    public static void sending_data(String message)
    {


        p.println(message);
        p.flush();

    }

}

And then on my MainActivity

   myComs.createSocket(getMyIp());

Getting my Myip form my set/get which i create from an input in a textfield thank you for the help

AsyncTask, doInBackground never runs in android

3 Answers3

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