mybatis 动态排序

public class Pagination {
    // 当前页
    private Integer page = 1;
    
    // 一页显示条数
    private Integer limit = 10;
    
    // 排序字段
    private String field;
    
    // 排序类型（desc（降序）、asc（升序）、null（空对象，默认排序））
    private String order;
    
}

Map<String, Object> map = new HashMap<String, Object>();
Integer page = pagination.getPage();
Integer limit = pagination.getLimit();
map.put("start", (page-1)*limit);
map.put("pageNo", limit);
map.put("field", pagination.getField());
map.put("order", pagination.getOrder());

<select id="queryMarkVoluntarilyList" parameterType="map" resultType="MarkVoluntarilyDto">
    select a.*, FROM_UNIXTIME(a.createTime,'%Y-%m-%d %H:%i:%s') AS createTimeStr from web_ei_voluntarily a
    <where>
        <if test="websiteName !=null and websiteName !=''">
            a.websiteName like concat(#{websiteName},'%')
        </if>
        <if test="websiteUrl !=null and websiteUrl !=''">
            and a.websiteUrl like concat(concat('%',#{websiteUrl}),'%')
        </if>
        <if test="companyName !=null and companyName !=''">
            and a.companyName like concat(concat('%',#{companyName}),'%')
        </if>
        <if test="deptCode !=null and deptCode !=''">
            <if test="containSub == '1'.toString()">
                and a.deptCode like concat(#{deptCode},'%')
            </if>
            <if test="containSub == '0'.toString()">
                and a.deptCode = #{deptCode}
            </if>
        </if>
        <if test="registrationCode !=null and registrationCode !=''">
            and a.registrationCode = #{registrationCode}
        </if>
        <if test="creditCode !=null and creditCode !=''">
            and a.creditCode like concat(#{creditCode},'%')
        </if>
    </where>
    <choose>
        <when test="field !=null and  field  !=''">
            ORDER BY ${field}  ${order}
        </when>
        <otherwise>
            ORDER BY a.createTime desc
        </otherwise>
    </choose>
    limit #{start}, #{pageNo}
</select>