1. findByIds(List<Integer> ids) 传入参数为单一list参数时的写法
<foreach item="id" index="index" collection="list" open="(" separator="," close=")">
#{id}
</foreach>
2. findByIds(Integer[] ids) 传入参数为单一数组时的写法
<foreach item="id" index="index" collection="array" open="(" separator="," close=")">
#{id}
</foreach>
3. search(Integer[] ids,String title) 传入参数为多个类型的查询条件时
Map<String, Object> params = new HashMap<String, Object>();
params.put("title", title);
params.put("ids", ids);
<foreach item="id" index="index" collection="ids" open="(" separator="," close=")">
#{id}
</foreach>
4.search(Person person) 传入参数为bean对象
<foreach item="id" index="index" collection="person.ids" open="(" separator="," close=")">
#{id}
</foreach>
四种方式应用不同的场景，主要是collection的参数不同
