Android: how to run a thread

Question

I want to test this RFCOMM server thread in my Android app. Basically I want to do exactly what that question's user wanted to do. I have never worked with threads before and really have no idea how to do this.

here's my MainActivity:

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

}
}

my server thread is the same:

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.UUID;

import android.app.Activity;
import android.bluetooth.*;
import android.util.Log;
import android.widget.RelativeLayout;
import android.widget.TextView;

public class RFCommServer extends Thread{

//based on java.util.UUID
private static UUID MY_UUID = UUID.fromString("446118f0-8b1e-11e2-9e96-0800200c9a66");

// The local server socket
private BluetoothServerSocket mmServerSocket;

// based on android.bluetooth.BluetoothAdapter
private BluetoothAdapter mAdapter;
private BluetoothDevice remoteDevice;

private Activity activity;

public RFCommServer(Activity activity) {
    this.activity = activity;
}

public void run() {
    BluetoothSocket socket = null;
    mAdapter = BluetoothAdapter.getDefaultAdapter();        

    // Listen to the server socket if we're not connected
    while (true) {

        try {
            // Create a new listening server socket
            Log.d(this.getName(), ".....Initializing RFCOMM SERVER....");

            // MY_UUID is the UUID you want to use for communication
            mmServerSocket = mAdapter.listenUsingRfcommWithServiceRecord("MyService",    MY_UUID);
            //mmServerSocket =  mAdapter.listenUsingInsecureRfcommWithServiceRecord(NAME, MY_UUID); // you can also try  using In Secure connection...

            // This is a blocking call and will only return on a
            // successful connection or an exception
            socket = mmServerSocket.accept();

        } catch (Exception e) {

        }

        try {
            Log.d(this.getName(), "Closing Server Socket.....");
            mmServerSocket.close();

            InputStream tmpIn = null;
            OutputStream tmpOut = null;

            // Get the BluetoothSocket input and output streams

            tmpIn = socket.getInputStream();
            tmpOut = socket.getOutputStream();

            DataInputStream mmInStream = new DataInputStream(tmpIn);
            DataOutputStream mmOutStream = new DataOutputStream(tmpOut);

            // here you can use the Input Stream to take the string from the client  whoever is connecting
            //similarly use the output stream to send the data to the client

            RelativeLayout layout = (RelativeLayout)  activity.findViewById(R.id.relativeLayout_Layout);
            TextView text = (TextView) layout.findViewById(R.id.textView_Text);

            text.setText(mmInStream.toString());
        } catch (Exception e) {
            //catch your exception here
        }
    }
}

}

you have a thread and in the thread's run method you access and update ui ( which is wrong) assuming you start the thread by calling `start()` — Raghunandan, Aug 21 '14 at 12:18
you can use handlers or eventbus from green robots. you need to start the thread by calling `start()` first — Raghunandan, Aug 21 '14 at 12:22
@blackbelt and the slideshare for the same http://www.slideshare.net/greenrobot/eventbus-for-android-15314813 — Raghunandan, Aug 21 '14 at 12:26
@blackbelt no not mine. this ie from greenrobots. there is similar evenbuts project by square its called otto http://gitthub.com/square/otto — Raghunandan, Aug 21 '14 at 12:29

score 1 · Answer 1 · answered Aug 21 '14 at 12:25

I would suggest you to use AsyncTask

The doInBackground() Method work in a separate thread and you can update your UI easily before starting execution in onPreExecute() Method and after Execution in onPostExecute() Method

Example to use AsyncTask

private class DownloadFilesTask extends AsyncTask<URL, Integer, Long> {
     protected Long doInBackground(URL... urls) {
         int count = urls.length;
         long totalSize = 0;
         for (int i = 0; i < count; i++) {
             totalSize += Downloader.downloadFile(urls[i]);
             publishProgress((int) ((i / (float) count) * 100));
             // Escape early if cancel() is called
             if (isCancelled()) break;
         }
         return totalSize;
     }

     protected void onProgressUpdate(Integer... progress) {
         setProgressPercent(progress[0]);
     }

     protected void onPostExecute(Long result) {
         showDialog("Downloaded " + result + " bytes");
     }
 }

Once created, a task is executed very simply:

 new DownloadFilesTask().execute(url1, url2, url3);

Android: how to run a thread

1 Answers1