title: speed up append to jTextArea in java swing when loading a lot of text
body: <p>I'm using <strong>JavaSwing</strong> for UI. I'm having to put a lot of text inside of a <code>jTextArea</code>; loading anywhere from 500KB to 5MB of text file into the <code>jTextArea</code></p>
  
  <pre class="lang-sh prettyprint-override"><code>BufferedReader br = new BufferedReader (new FileReader("filename.txt"));
  txtarea.read(br,null);
  br.close;
  txtarea.requestFocus();
  </code></pre>
  
  <p>but when read <code>filename.txt</code> then append to text area is very slow.
  I tried append <code>txtarea.append(String text)</code> or <code>txtarea.setText(String text)</code> but it unimproved and very slowly. </p>
  
  <p>Thanks for any attention in advance!</p>