mybaties 的and or 條件 xml 判斷

<if test="goodsCode !=null and goodsCode !='' and supplier  !=null and supplier  !='' ">
    goods_code =#{goodsCode}  and   supplier  =#{supplier}
</if>
<if test="goodsCode !=null and goodsCode !='' and (supplier  ==null or supplier  !='')">
    goods_code =#{goodsCode}  and   supplier   is  null
</if>