Mybatis对复杂对象参数中的整数列表进行迭代

Question

我在Play Framework 2.3.6 Java项目中使用MyBatis 3.2.8.我已经挣扎了几天,迭代遍历复杂对象参数中的MyBatis映射器的整数列表.这是我的设置:

我在EventFilter.java中有一个名为EventFilter的类:

public class EventFilter {
private String beginDate;
private String endDate;
private List<Integer> closestCountry;
private List<Integer> territorialWaterStatus;
private List<Integer> vesselCountry;
private String closestCountryInClause;
private String territorialWaterStatusInClause;
private String vesselCountryInClause;

public EventFilter() { }

public EventFilter(JsonNode jsonNode){
    this.beginDate = jsonNode.get("beginDate").asText();
    this.endDate = jsonNode.get("endDate").asText();
    this.closestCountry = JsonHelper.arrayNodeToIntegerList((ArrayNode) jsonNode.get("closestCountry"));
    this.territorialWaterStatus = JsonHelper.arrayNodeToIntegerList((ArrayNode) jsonNode.get("territorialWaterStatus"));
    this.vesselCountry = JsonHelper.arrayNodeToIntegerList((ArrayNode) jsonNode.get("vesselCountry"));
}

public String getBeginDate() {
    return beginDate;
}

public void setBeginDate(String beginDate) {
    this.beginDate = beginDate;
}

public String getEndDate() {
    return endDate;
}

public void setEndDate(String endDate) {
    this.endDate = endDate;
}

public List<Integer> getTerritorialWaterStatus() {
    if(this.territorialWaterStatus.size() > 0) {
        return territorialWaterStatus;
    } else {
        return null;
    }
}

public void setTerritorialWaterStatus(List<Integer> territorialWaterStatus) {
    this.territorialWaterStatus = territorialWaterStatus;
}

public List<Integer> getClosestCountry() {
    if(this.closestCountry.size() > 0) {
        return closestCountry;
    } else {
        return null;
    }
}

public void setClosestCountry(List<Integer> closestCountry) {
    this.closestCountry = closestCountry;
}

public List<Integer> getVesselCountry() {
    if(this.vesselCountry.size() > 0) {
        return vesselCountry;
    } else {
        return null;
    }
}

public void setVesselCountry(List<Integer> vesselCountry) {
    this.vesselCountry = vesselCountry;
}

}

这在我的mybatis配置文件中被引用为类型别名:

<configuration>

<typeAliases>
    <typeAlias type="models.Event" alias="Event"/>
    <typeAlias type="models.EventFilter" alias="EventFilter"/>
    <typeAlias type="models.Country" alias="Country"/>
</typeAliases>

<environments default="development">
    <environment id="development">
        <transactionManager type="JDBC"/>
        <dataSource type="POOLED">
            <property name="driver" value="org.postgresql.Driver"/>
            <property name="url" value="jdbc:postgresql://localhost:5432/mpmap"/>
            <property name="username" value="postgres"/>
            <property name="password" value="dbpw"/>
        </dataSource>
    </environment>
</environments>

<mappers>
    <mapper resource="EventMapper.xml"/>
</mappers>
</configuration>

我有一个mapper,它以EventFilter对象作为参数.然后应检查是否设置了beginDate,endDate,nearestCountry,vesselCountry和territorialWaterStatus.如果是,它将它们用于WHERE子句:

<select id="getEventsWithFilter" resultType="Event" resultMap="EventResult">
    SELECT ev.id, to_char(ev.occurred_on, 'YYYY-MM-DD') AS occurred_on_date,
        to_char(ev.occurred_on, 'HH24:MI:SS') AS occurred_on_time,
        ST_X(ev.location) AS longitude, ST_Y(ev.location) AS latitude,
        COALESCE(co01.name, 'Unspecified') AS closest_country,
        COALESCE(co02.name, 'Unspecified') AS territorial_water_status,
        COALESCE(co03.name, 'Unspecified') AS vessel_flag_country
    FROM event AS ev
    LEFT JOIN country AS co01
        ON co01.cow_id = ev.location_closest_country_id
    LEFT JOIN country AS co02
        ON co02.cow_id = ev.location_water_status_country_id
    LEFT JOIN country AS co03
        ON co03.cow_id = ev.vessel_flag_country_id
    <where>
        <if test="#{eventFilter.beginDate} != null and #{eventFilter.endDate} != null">
            ev.occurred_on &gt;= #{eventFilter.beginDate}::timestamp AND ev.occurred_on &lt;= #{eventFilter.endDate}::timestamp
        </if>
        <if test="#{eventFilter.closestCountry} != null">
            AND ev.location_closest_country_id IN
            <foreach item="id" index="index" collection="#{eventFilter.closestCountry}" open="(" separator="," close=")">
                #{id}
            </foreach>
        </if>
        <if test="#{eventFilter.territorialWaterStatus} != null">
            AND ev.location_water_status_country_id IN
            <foreach item="id" index="index" collection="#{eventFilter.territorialWaterStatus}" open="(" separator="," close=")">
                #{id}
            </foreach>
        </if>
        <if test="#{eventFilter.vesselCountry} != null">
            AND ev.vessel_flag_country_id IN
            <foreach item="id" index="index" collection="#{eventFilter.vesselCountry}" open="(" separator="," close=")">
                #{id}
            </foreach>
        </if>
    </where>
    ORDER BY ev.occurred_on ASC;
</select>

我将映射器链接到一个接口,如下所示:

    public List<Event> getEventsWithFilter(@Param("eventFilter") EventFilter eventFilter);

我用MybatisMapper辅助类调用它来生成我的会话,如下所示:

public static List<Event> getEvents(EventFilter eventFilter) {
    MybatisMapper mapper = new MybatisMapper();
    SqlSession session = mapper.getSession();
    EventMapper eventMapper = session.getMapper(EventMapper.class);

    List<Event> events;

    List<Integer> li = eventFilter.getClosestCountry();

    try {
        events = eventMapper.getEventsWithFilter(eventFilter);
    } finally {
        session.close();
    }

    return events;
}

问题:

beginDate和endDate自己完全正常工作.但是我对整数列表有以下问题:

1. 检查列表是否为null的if语句似乎被忽略,或者当它应该为false时评估为true.
2. 整数列表似乎作为null传递给IN子句.
3. 如果我注释掉整数列表的IN子句,只是注释到beginDate和endDate,它就可以正常工作.但是,如果我保留整数列表IN子句,查询不会失败,但它返回一个空集,就像说"WHERE列IN()".

这是执行映射器/查询时由Play和Mybatis打印的控制台日志记录,以及EventFilter打印其内容.它们有点冗长所以我把它们放在pastebin中:

• 当我为三个整数列表中的每一个传递三个国家时:http://pastebin.com/aWcXyikh
• 当我只传递beginDate和endDate时:http://pastebin.com/CeCv256g

这比我想要的要长一点,但提前感谢任何帮助或建议.

Answer 1

我终于搞定了.我最不得不改变的是在我的XML映射器中寻址参数列表而没有周围的花括号.

所以代替:

 <if test="#{eventFilter.closestCountry} != null">
        AND ev.location_closest_country_id IN
        <foreach item="id" index="index" collection="#{eventFilter.closestCountry}" open="(" separator="," close=")">
            #{id}
        </foreach>
    </if>

它应该是:

<if test="eventFilter.closestCountry != null">
            AND ev.location_closest_country_id IN
            <foreach item="id" index="index" collection="eventFilter.closestCountry" open="(" separator="," close=")">
                #{id}
            </foreach>
        </if>

这很奇怪,因为传递对象中的寻址字符串可以使用任何一种方法 - 即#{eventFilter.beginDate}与eventFilter.beginDate相同.

一个非常微妙的区别,但我希望它可以帮助别人节省一些时间.