log4j.properties一般配置文件如下：

注意INFO是发布到网站站点时是INFO模式

log4j.rootLogger=INFO,Console,File

log4j.appender.Console=org.apache.log4j.ConsoleAppender

log4j.appender.Console.Target=System.out

log4j.appender.Console.layout=org.apache.log4j.PatternLayout

log4j.appender.Console.layout.ConversionPattern=[%c]%m%n

log4j.appender.File=org.apache.log4j.RollingFileAppender 

log4j.appender.File.File=mybatis.log

log4j.appender.File.MaxFileSize=10MB

log4j.appender.File.Threshold=ALL

log4j.appender.File.layout=org.apache.log4j.PatternLayout

log4j.appender.File.layout.ConversionPattern=[%p][%d{yyyy-MM-dd HH\:mm\:ss,SSS}][%c]%m%n

简化一下语法为：

SELECT

`user`.id,

`user`.`name`,

`user`.loginname,

`user`.pwd,

`user`.mobile,

group_user.id groupuser_id ,

group_user.userid user_id,

group_user.groupid group_id,

`group`.id groupid,

`group`.groupname group_name,

`group`.createtime group_createtime

FROM

`user`

JOIN group_user ON `user`.id = group_user.userid

JOIN `group` ON group_user.groupid = `group`.id

/mybatis/src/main/java/sy/mapping/UserMapper.xml

<resultMap type="sy.model.User" id="userResultMap3" extends="BaseResultMap">

<collection property="groupUsers" javaType="list" ofType="sy.model.GroupUser">

<id column="groupuser_id" property="id" />

<result column="user_id" property="userid" />

<result column="group_id" property="groupid" />

<association property="groups" javaType="sy.model.Group">

<id property="id" column="groupid"/>

<result property="groupname" column="group_name"/>

</association>

</collection>

</resultMap>

<select id="getAll3" resultMap="userResultMap3">

SELECT

`user`.id,

`user`.`name`,

`user`.loginname,

`user`.pwd,

`user`.mobile,

group_user.id groupuser_id ,

group_user.userid user_id,

group_user.groupid group_id,

`group`.id groupid,

`group`.groupname group_name

FROM

`user`

JOIN group_user ON `user`.id = group_user.userid

JOIN `group` ON group_user.groupid = `group`.id

</select>

最后注意：

得到一个新的maven 项目请做如下操作：

再次：