mybatis實現數據懶加載

要實現mybatis的數據懶加載，需要進行相關配置，首先要在mybatis的configuration中添加如下設置

<settings>
    <setting name="lazyLoadingEnabled" value="true"/>
    <setting name="aggressiveLazyLoading" value="false"/>
</settings>

 

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.sealong.dao.IUserDao">
    <resultMap id="UserAccount" type="com.sealong.domain.User">
        <id property="id" column="id"></id>
        <result column="username" property="username"></result>
        <result column="birthday" property="birthday"></result>
        <result column="sex" property="sex"></result>
        <result column="address" property="address"></result>
        <!--select中的值，需要進行數據懶加載的方法
            column爲方法中所要傳入的參數
            accounts爲對象User中的一個屬性名
            ofType爲accounts屬性名所對應的對象類
        -->
        <collection property="accounts" select="com.sealong.dao.IAccountDao.findAccountByUId" column="id" ofType="Account"></collection>
    </resultMap>

    <select id="findAll" resultMap="UserAccount">
        select *  from user
    </select>
</mapper>