private void selectFile() {
    File f = rest_ui.getOpenFile(FileChooserType.OPEN_REQUEST_BODY);
    if (f == null) { // Pressed cancel?
      return;
    }
    if (!f.canRead()) {
      JOptionPane.showMessageDialog(
          rest_ui.getFrame(),
          "File not readable: " + f.getAbsolutePath(),
          "IO Error",
          JOptionPane.ERROR_MESSAGE);
      return;
    }

    // Content type charset correction:
    ContentTypeSelectorOnFile.select(jp_contentType, f, this);

    // Set name:
    if (StringUtil.isEmpty(jtf_fileName.getText())) {
      jtf_fileName.setText(f.getName());
    }

    // Set file:
    jtf_file.setText(f.getAbsolutePath());
  }
 @Override
 public void clear() {
   jp_contentType.clear();
   jtf_fileName.setText("");
   jtf_file.setText("");
 }