Question

First I will explain the current situation.
I’ve 2 different threads in 2 services(read from usb port service and make web requests service). I’m starting them in onCreate of my activity like:

serialServiceIntent = new Intent(NDKSerialActivity.this, SerialService.class);
startService(serialServiceIntent);
webServiceIntent = new Intent(NDKSerialActivity.this, RecordWebService.class);
startService(webServiceIntent);

There is nothing wrong with serial service but in RecordWebService when I make a request my gui stops until response comes.

The code is like that:

public class RecordWebService extends Service
{
public static final String SERVER_ADDRESS = "http://192.168.1.100:8080/MobilHM/rest";
private static final String TAG = RecordWebService.class.getSimpleName();
private RecordWebThread recordWebThread;

@Override
public void onStart(Intent intent, int startId)
{
    super.onStart(intent, startId);
    recordWebThread = new RecordWebThread(true);
    recordWebThread.start();
}

@Override
public void onDestroy()
{
    super.onDestroy();
    Log.i(TAG, "RecordWebService Destroyed");
}

@Override
public IBinder onBind(Intent intent)
{
    return null;
}
}

and

public class RecordWebThread extends Thread
{
private static final String TAG = RecordWebThread.class.getSimpleName();
public boolean always;


public RecordWebThread(boolean always)
{
    this.always = always;
}

@Override
public void run()
{
    PatientRecord patientRecord = new PatientRecord();
    while (always)
    {
        RestClient restClient = new RestClient(RecordWebService.SERVER_ADDRESS + "/hello");
        try
        {
            restClient.execute(RequestMethod.GET);
        }
        catch (Exception e1)
        {
            Log.e(TAG, "", e1);
        }
        Log.i(TAG, "Server Response Code:->" + restClient.getResponseCode());
        Log.i(TAG, "Server Response:->" + restClient.getResponse());
        try
        {
            sleep(4 * 1000);
        }
        catch (InterruptedException e)
        {
            Log.e(TAG, "Web service interrupted", e);
        }
    }
}
}

Also I’ve tried to remove sleep part and make the thread to run with timer and timer task like:

public void sendRecord()
{
    scanTask = new TimerTask()
    {
        public void run()
        {
            handler.post(new Runnable()
            {
                public void run()
                {
                    RestClient restClient = new RestClient(RecordWebService.SERVER_ADDRESS + "/hello");
                    try
                    {
                        restClient.execute(RequestMethod.GET);
                    }
                    catch (Exception e1)
                    {
                        Log.e(TAG, "", e1);
                    }
                    Log.i(TAG, "Server Response Code:->" + restClient.getResponseCode());
                    Log.i(TAG, "Server Response:->" + restClient.getResponse());
                }
            });
        }
    };
    t.schedule(scanTask, 1000, 4000);
}

but no luck, my gui hangs when it comes to restClient.execute .

You can find RestClient.java @ http://www.giantflyingsaucer.com/blog/?p=1462

How can I make my requests not block my gui thread?

Edit:

public void sendRecord()
{
    scanTask = new TimerTask()
    {
        public void run()
        {
            RestClient restClient = new RestClient(RecordWebService.SERVER_ADDRESS + "/hello");
            try
            {
                restClient.execute(RequestMethod.GET);
            }
            catch (Exception e1)
            {
                Log.e(TAG, "", e1);
            }
            Log.i(TAG, "Server Response Code:->" + restClient.getResponseCode());
            Log.i(TAG, "Server Response:->" + restClient.getResponse());
        }
    };
    t.schedule(scanTask, 1000, 4000);
}

Without handler, I call this in onCreate of my activity but still ui hanging.

Answer 1

Or you can use an IntentService which will handle the thread issues for you.

This is an example class:

public class MyService extends IntentService {

    public MyService() {
        super("MyService");
    }

    public MyService(String name) {
        super(name);        
    }

    @Override
    protected void onHandleIntent(Intent arg0) {

                //Do what you want
        }
}

Then you just call:

Intent intent = new Intent(getApplicationContext(),MyService.class);
startService(intent);

Edit:

To repeat the same thing every 4 seconds you should do something like this:

 PendingIntent serviceIntent= PendingIntent.getService(context,
                0, new Intent(context, MyService.class), 0);

   long firstTime = SystemClock.elapsedRealtime();
   AlarmManager am = (AlarmManager)context.getSystemService(Context.ALARM_SERVICE);

   long intervalInSec = 4;

   am.setRepeating(AlarmManager.ELAPSED_REALTIME, firstTime, intervalInSec*1000, serviceIntent)

;