radio自带回显和默认选中

<input type="radio" name="state" <c:if test="${empty model.state || model.state == 'Y'}">checked="checked"</c:if> value="Y"/> 启用

<input type="radio" name="state" <c:if test="${model.state == 'N'}">checked="checked"</c:if> value="N"/> 停用