private byte[] sourceData() {
        if (jRadioButtonMenuItem1.isSelected()) {
            try {
                return jTextArea1.getText().getBytes("UTF-8");
            } catch (UnsupportedEncodingException ex) {
                Logger.getLogger(MainFrame.class.getName()).log(Level.SEVERE, null, ex);
            }
        }
        if (jRadioButtonMenuItem2.isSelected()) {
            JFileChooser fileChooser = new JFileChooser();
            fileChooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
            fileChooser.setMultiSelectionEnabled(false);
            int showOpenDialog = fileChooser.showOpenDialog(this);
            if (showOpenDialog == JFileChooser.CANCEL_OPTION) {
                return new byte[0];
            }
            try {
                return org.apache.commons.io.FileUtils.readFileToByteArray(fileChooser.getSelectedFile());
            } catch (IOException ex) {
                Logger.getLogger(MainFrame.class.getName()).log(Level.SEVERE, null, ex);
            }
        }

        return new byte[0];
    }