public class TestActivity implement GetTextCallback {
   public interface GetTextCallback {
       String getText()
   }

   @Override
   public String getText() {
       return editText.getText().toString();
   }
}

@Override
public void onAttach(Activity activity) {
    super.onAttach(activity);
    if (getTextCallback == null) {
        getTextCallback = (GetTextCallback) activity;
    }
}

public void whenYouWantToGetText() {
    if (getTextCallback != null) {
        getTextCallback.getTextYouWant();
    }
}