How rebuild only one module in project Android Studio

 String sTitle = "My new title";
 setTitle(sTitle);

public class HoriziontalScrollActivity extends Activity {
	TextView txtV;
	Context cntx;
	
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        txtV = (TextView)findViewById(R.id.idLabel);
        cntx = this;
        StringBuilder strBuild = new StringBuilder();

        // enter your date of birth
        Calendar dateOfYourBirth = new GregorianCalendar(1998, Calendar.SEPTEMBER, 17);
        Calendar today = Calendar.getInstance();
        int yourAge = today.get(Calendar.YEAR) - dateOfYourBirth.get(Calendar.YEAR);
        dateOfYourBirth.add(Calendar.YEAR, yourAge);
        if (today.before(dateOfYourBirth)) {
            yourAge--;
        }  
        strBuild.append("You are " + yourAge + " old!");
         txtV.setText(strBuild);
    }
}

Context context = thisClass.this;
Drawable image = ImageOperations(context,
"//www.okhelp.cz/images/android/ad_4.png"
,"image.jpg");
ImageView imgView;
imgView = (ImageView)findViewById(R.id.idImageView);
imgView.setImageDrawable(image);

	private Drawable ImageOperations(Context ctx, String url, String saveFilename) {
		try {
			InputStream is = (InputStream) this.fetch(url);
			Drawable d = Drawable.createFromStream(is, "src");
			return d;
		} catch (MalformedURLException e) {
			e.printStackTrace();
			return null;
		} catch (IOException e) {
			e.printStackTrace();
			return null;
		}
	}

	public Object fetch(String address) throws MalformedURLException,IOException {
		URL url = new URL(address);
		Object content = url.getContent();
		return content;
	}

public class MyClass extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
       }
	 String sMyText = "some text";
	 int nMyInt = 10;

 @Override
 protected void onSaveInstanceState(Bundle outState) {
     // Save away the original text, so we still have it if the activity
     // needs to be killed while paused.
     outState.putString("my_text", sMyText);
     outState.putInt("my_int", nMyInt);
     Toast.makeText(this, "onSaveInstanceState()", Toast.LENGTH_LONG).show();
Log.i("onSaveInstanceState", "onSaveInstanceState()");
}
 String sNewMyText = "";
 int nNewMyInt = 0;
 
 @Override
 protected void onRestoreInstanceState(Bundle savedInstanceState) {
     super.onRestoreInstanceState(savedInstanceState);
     // restore saved values
     sNewMyText = savedInstanceState.getString("my_text");
     nNewMyInt = savedInstanceState.getInt("my_int");
     Toast.makeText(this, "onRestoreInstanceState()", Toast.LENGTH_LONG).show();
     Log.i("onRestoreInstanceState", "onRestoreInstanceState()");
     
 }
}