spring+mybatis,如何在http请求中共享数据库连接

Question

我创建了一个mvc控制器来处理用户的登录请求。

在控制器中，我需要完成一些与数据库相关的任务，每个任务将访问一个由spring自动连线的mybatis映射器的服务对象，这将创建一个mybatis sqlsession并使用它和关闭它。

我的问题是，我们能让所有这些任务共享同一个mybatis sqlsession吗？

here is the logging message in the real example of my application:
19:26:29.959 [http-8080-3] DEBUG org.mybatis.spring.SqlSessionUtils - Creating a new SqlSession
19:26:29.959 [http-8080-3] DEBUG org.mybatis.spring.SqlSessionUtils - SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@c1c7c4] was not registered for synchronization because synchronization is not active
19:26:30.001 [http-8080-3] DEBUG org.mybatis.spring.transaction.SpringManagedTransaction - JDBC Connection [jdbc:h2:tcp://127.0.0.1:6001/cmp, UserName=SA, H2 JDBC Driver] will not be managed by Spring
19:26:30.002 [http-8080-3] DEBUG org.codingfarm.cwe.sys.mappers.UrlRoleMapper.countByExample - ==>  Preparing: select count(*) from CMP.PUBLIC.SYS_URL_ROLES WHERE ( URL = ? ) 
19:26:30.002 [http-8080-3] DEBUG org.codingfarm.cwe.sys.mappers.UrlRoleMapper.countByExample - ==> Parameters: index.jsp(String)
19:26:30.008 [http-8080-3] DEBUG org.codingfarm.cwe.sys.mappers.UrlRoleMapper.countByExample - <==      Total: 1
19:26:30.008 [http-8080-3] DEBUG org.mybatis.spring.SqlSessionUtils - Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@c1c7c4]
19:26:30.008 [http-8080-3] DEBUG org.mybatis.spring.SqlSessionUtils - Creating a new SqlSession
19:26:30.009 [http-8080-3] DEBUG org.mybatis.spring.SqlSessionUtils - SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@37c7ee] was not registered for synchronization because synchronization is not active
19:26:30.010 [http-8080-3] DEBUG org.mybatis.spring.transaction.SpringManagedTransaction - JDBC Connection [jdbc:h2:tcp://127.0.0.1:6001/cmp, UserName=SA, H2 JDBC Driver] will not be managed by Spring
19:26:30.010 [http-8080-3] DEBUG org.codingfarm.cwe.sys.mappers.UrlRoleMapper.countByExample - ==>  Preparing: select count(*) from CMP.PUBLIC.SYS_URL_ROLES WHERE ( URL = ? and ROLE_ID in ( ? , ? ) ) 
19:26:30.011 [http-8080-3] DEBUG org.codingfarm.cwe.sys.mappers.UrlRoleMapper.countByExample - ==> Parameters: index.jsp(String), system(String), basic(String)
19:26:30.012 [http-8080-3] DEBUG org.codingfarm.cwe.sys.mappers.UrlRoleMapper.countByExample - <==      Total: 1
19:26:30.012 [http-8080-3] DEBUG org.mybatis.spring.SqlSessionUtils - Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@37c7ee]

那么如何让多个映射器共享一个SqlSessionTemplate呢？

Answer 1

最简单的方法是使用SQLSessionFactoryBean。

如果您有这样定义

<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
    <property name="dataSource" ref="dataSource"/>
    <property name="configLocation" value="classpath:myBatisConfig.xml" />
</bean>

然后可以逐个定义映射器bean

<bean id="userMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">
  <property name="mapperInterface" value="com.yourcompany.youapp.mapper.SomeMapper" />
  <property name="sqlSessionFactory" ref="sqlSessionFactory" />
</bean>

或者使用MapperScannerConfigureer通过扫描映射器类来实例化所有映射器

<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
    <property name="basePackage" value="com.yourcompany.youapp.mapper" />
    <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
</bean>