[Struts2]多個默認值的下拉選單

官網的Example

<s:select label="Pets"
      name="petIds"
      list="petDao.pets"
      listKey="id"
      listValue="name"
      multiple="true"
      size="3"
      required="true"
      value="%{petDao.pets.{id}}"
/>

%{petDao.pets.{id}}的值有出現在listKey的id裡
就會被auto-selected