You can migrate it to widgets using ListBox:
<g:ListBox>
<g:item value='AND'>AND</g:item>
<g:item value='OR'>OR</g:item>
</g:ListBox>
Or keep it as elements using HTMLPanel:
<g:HTMLPanel>
<select>
<option value="AND">AND</option>
<option value="OR">OR</option>
</select>
</g:HTMLPanel>
textList = textList.stream().map(s -> "%" + s).collect(Collectors.toList());for your other question. BUT, it creates a new List object and uses a loop both behind the scenes, breaking your requirements