gistfile1.java

/*
Here's my test view, actuclly I'm using a swipping view that's why I'm using Fragments…(nvm about that!)

Here, I'm making this class "implements URLThread_CallBack";
	 providing implementation for a URLCallBack(String resp) function
*/

public class view4sqr extends Fragment implements OnClickListener,URLThread_CallBack
{
  
  View v; //view to be updated later; better be a global variable
	URLThread connect=null;
  
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) 
    {
        v=inflater.inflate(R.layout.view4sqr, container, false);
        
        Button checkin= (Button)v.findViewById(R.id.checkin);
        checkin.setOnClickListener(this);
        return v;
    }
    // ....to be continued later
}

gistfile2.java

/*
	I know a dude used to keep pressing & releasing fingers on same button as if things will get faster!
	
	don't worry, here's a deal for such kind of people, 
	yes,initizaling the thread object with NULL & do nothing if it's already alive!
	& let dudes have fun with the buttons ;)
*/

public class view4sqr extends Fragment implements OnClickListener,URLThread_CallBack
{
// ...
  @Override
  public void onClick(View v)
	{
		switch (v.getId())
		{
			case R.id.checkin: //matching some button id
				if(connect==null)
				{
					connect=new URLThread("http://smth.smth", this, "my POST data");
					connect.start();
				}
		}
	}
//...
}

gistfile3.java

/*
	Here's the trick!
	DON'T EVER change UI all of sudden; App will clash!
	Instread, ask the UI to run this seperate Thread to deal with when free :)
*/

public class view4sqr extends Fragment implements OnClickListener,URLThread_CallBack
{
//...

  @Override
  public void URLCallBack(String resp)
	{
		final String res=resp;
		this.getActivity().runOnUiThread(
				new Runnable()
				{
			            public void run()
			            {
				            	TextView tv=(TextView) v.findViewById(R.id.textView1);
				        		tv.setText(res);
			            }
				}
		);
	}
    
}

URLThread_CallBack.java

/*
First, you need to force people (or just yourself) to create a Call-Back function;
something that will be called to handle URLConnection responses
*/

interface URLThread_CallBack
{
  public void URLCallBack(String response);
}