mybatis判断list为空

在传入的map或者对象里面存在一个list,此时想要判断list是否为空,可以

<if test="spids.size()>0 " >
        and  SPid not in
        <foreach collection="spids" item="id" index="index"
                 open="(" close=")" separator=",">
          #{id}
        </foreach>
</if>