title: Android Studio Error: Method getText() must be called from the UI Thread
body: <p>I'm working on app which shows the lyrics of song. And I have got an error: Method getText() must be called from the UI Thread. I was searching for answer, but no answer has helped solve the problem. </p>
  
  <pre><code>public class HomeActivity extends AppCompatActivity {
  
  private EditText wykonawca;
  private EditText tytul;
  private Button pokazTekst;
  private TextView tekst;
  
  //String url = "http://www.tekstowo.pl/piosenka,";
  String title;
  
  
  
  @Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_home);
  
      FindViews();
  
  
  
      tekst.setMovementMethod(new ScrollingMovementMethod()); // mozliwosc scrolowania tekstu
  
      pokazTekst.setOnClickListener(new View.OnClickListener() {
          @Override
          public void onClick(View v) {
  
              new SongText().execute();
          }
      });
  
  }
  
  public class SongText extends AsyncTask&lt;Void, Void, Void&gt;{
  
      String url = "http://www.tekstowo.pl/piosenka,";
      String author;
      String song_name;
  
      @Override
      protected Void doInBackground(Void... params) {
  
          try {
              // here is error
              author = wykonawca.getText().toString();
              song_name = tytul.getText().toString();
  
              url = url + author + "," + song_name + ".html";
  
              Document doc = Jsoup.connect(url).get();
  
              title = doc.select("div[class=song-text").text();
          }
  
          catch (IOException e){
              e.printStackTrace();
          }
  
          return null;
      }
  
      @Override
      protected void onPostExecute(Void aVoid) {
          super.onPostExecute(aVoid);
  
          tekst.setText(title);
      }
  }
  
  private void FindViews(){
  
      // Edit text
      wykonawca = (EditText) findViewById(R.id.wykonawca);
      tytul = (EditText) findViewById(R.id.tytul);
  
      // Buttons
      pokazTekst = (Button) findViewById(R.id.pokazTekst);
  
      // TextViews
      tekst = (TextView) findViewById(R.id.tekst);
  
  }
  </code></pre>
  
  <p>}</p>