Spring4+Mybatis3+PostgreSql整合中遇到的问题
1、首先说一下SqlSessionDaoSupport的问题，在mybatis-spring1.1的时候我们直接这样写：
@Repository
public class PersonnelDaoImpl extends SqlSessionDaoSupport implements
PersonnelDao {
@Override
public Personnel getById(Integer id) {
return this.getSqlSession().selectOne(
"com.sanmina.tms.entity.Personnel.getById", id);
}
}
只需加上@Respositry 就可以了。但是在mybatis-spring1.2以后SqlSessionDaoSupport的源码有所改动（具体改动自己看源码），也就是说用上面的这种做法就会报错，如下：
Caused by: java.lang.IllegalArgumentException: Property 'sqlSessionFactory' or 'sqlSessionTemplate' are required at org.springframework.util.Assert.notNull(Assert.java:112) at org.mybatis.spring.support.SqlSessionDaoSupport.checkDaoConfig(SqlSessionDaoSupport.java:74) at org.springframework.dao.support.DaoSupport.afterPropertiesSet(DaoSupport.java:44) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1625) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1562) ... 12 more
所以我们就要在原来的代码上加上一点东西如下，自动加上sqlSessionFactory。
@Repository
public class PersonnelDaoImpl extends SqlSessionDaoSupport implements
PersonnelDao {
@Override
public Personnel getById(Integer id) {
return this.getSqlSession().selectOne(
"com.sanmina.tms.entity.Personnel.getById", id);
}
@Override
@Autowired
public void setSqlSessionFactory(SqlSessionFactory sqlSessionFactory) {
super.setSqlSessionFactory(sqlSessionFactory);
}
}
直接重写setSqlSessionFactory()方法，并加上@Autowired。Ok！
继续往下走，问题又来了：
2、mybatis 的mapping.xml中的resultMap和resultType的问题：
Caused by: org.apache.ibatis.executor.ExecutorException: A query was run and no Result Maps were found for the Mapped Statement 'com.sanmina.tms.entity.Personnel.getById'. It's likely that neither a Result Type nor a Result Map was specified. at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.validateResultMapsCount(DefaultResultSetHandler.java:234) at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.handleResultSets(DefaultResultSetHandler.java:157) at org.apache.ibatis.executor.statement.PreparedStatementHandler.query(PreparedStatementHandler.java:63) at org.apache.ibatis.executor.statement.RoutingStatementHandler.query(RoutingStatementHandler.java:78) at org.apache.ibatis.executor.BatchExecutor.doQuery(BatchExecutor.java:91) at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:303) at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:154) at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:102) at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:82)
原因是我的xml里没有写resultMap或者resultType：
<select id="getById" parameterType="Integer" >
select * from tb_personnel where id = #{id}
</select>
于是我加上：
<select id="getById" parameterType="Integer" resultMap="Personnel">
select * from tb_personnel where id = #{id}
</select>
问题又来了：
Caused by: java.lang.IllegalArgumentException: Result Maps collection does not contain value for com.sanmina.tms.entity.Personnel.personnel at org.apache.ibatis.session.Configuration$StrictMap.get(Configuration.java:818) at org.apache.ibatis.session.Configuration.getResultMap(Configuration.java:570) at org.apache.ibatis.builder.MapperBuilderAssistant.setStatementResultMap(MapperBuilderAssistant.java:356) ... 17 more
原因是resultMap需要自己配置，于是我又加上了如下的配置：
<resultMap type="Personnel" id="personnel">
</resultMap>
<select id="getById" parameterType="Integer" resultMap="personnel">
select * from tb_personnel where
id = #{id}
</select>
心想这个TM总能走了吧。于是结果如下：
Personnel [id=1, employeeID=null, companyID=null, cnName=null, department=CDC IT, section=SFDC team, positonName=null, superiorName=null, remarkDesc=null, emClassic=null]
长吁一口气，终于出来结果了。。。TM再仔细一数据，怎么有的是null，在查数据库明明不是null啊。真是日了狗...于是接着走。终于找到问题所在：因为我的实体类的有的字段和数据表的字段不是对应的，所以我们要将字段配置对应关系： 如下
<resultMap type="Personnel" id="personnel">
<id property="id" column="id"/>
<result property="employeeID" column="employee_id"/>
<result property="companyID" column="company_id"/>
<result property="cnName" column="cn_name"/>
<result property="positonName" column="position_name"/>
<result property="superiorName" column="superior_name"/>
<result property="remarkDesc" column="remark_desc"/>
<result property="emClassic" column="em_classic"/>
</resultMap>
<select id="getById" parameterType="Integer" resultMap="personnel">
select * from tb_personnel where
id = #{id}
</select>
在走！：
Personnel [id=1, employeeID=1016969, companyID=22222, cnName=Mercy, department=CDC IT, section=SFDC team, positonName=programer, superiorName=Tommy, remarkDesc=XXX, emClassic=IDE]
终于TM的Ok了，容我喝口水先......
源码的git地址：https://git.oschina.net/mercy_yang/SMP-Demo