List MyBatis incoming query data collection as a condition

SSM framework is used, the database is MySQL, make inquiries when incoming List collection, use SQL statements to query data in the way 
there are two main problems: My List collection is the use of another statement out of the query, passing parameters is of type int, the return value is of type int List collection:

public List<Integer> select(Integer id);

<select id="select" resultType="java.util.List" parameterType="java.lang.Integer">
    select id from section where status='A' and unitId=#{id,jdbcType=INTEGER}
</select>

This is the first time when I return to use value types (java.util.List), in which case I will perform error : java.lang.UnsupportedOperationException
In fact, we are here if you want to return a collection of the specified type directly write java.lang.Integer (int type) java.lang.String (string), etc. can, of course, you can also customize a resultMap

<select id="select" resultType="java.lang.Integer" parameterType="java.lang.Integer">
    select id from section where status='A' and unitId=#{id,jdbcType=INTEGER}
</select>

The above is by id check out a List collection, the following is found in the List collection into the query criteria:

public List<JUMember> selectById(List<Integer> id);

<select id="selectById" parameterType="java.util.List" resultMap="BaseResultMap">
    select * from jumember where status = 'A' and id in
    <foreach collection="list" index="index" item="item" open="("separator="," close=")">
        #{item}
    </foreach>
</select>

Data collection using foreach loop statement, item is recycled to the data, if you are a sophisticated type of data do, then you can use bulk insert item. Way to obtain the corresponding value of the property name