MyBatis Spring整合配置映射接口類與映射xml文件

Spring整合MyBatis使用到了mybatis-spring，在配置mybatis映射文件的時候，一般會使用MapperScannerConfigurer，MapperScannerConfigurer會自動掃描basePackage指定的包，找到映射接口類和映射XML文件，並進行注入。配置如下：

 

<!-- 數據源 -->
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
    <property name="driverClass" value="${${database.type}.jdbc.driverClassName}"/>
    <property name="jdbcUrl" value="${${database.type}.jdbc.url}"/>
    <property name="properties" ref="dataSourceProperties"/>
    <property name="autoCommitOnClose" value="true"/>
    <property name="checkoutTimeout" value="${cpool.checkoutTimeout}"/>
    <property name="initialPoolSize" value="${cpool.minPoolSize}"/>
    <property name="minPoolSize" value="${cpool.minPoolSize}"/>
    <property name="maxPoolSize" value="${cpool.maxPoolSize}"/>
    <property name="maxIdleTime" value="${cpool.maxIdleTime}"/>
    <property name="acquireIncrement" value="${cpool.acquireIncrement}"/>
    <property name="maxIdleTimeExcessConnections" value="${cpool.maxIdleTimeExcessConnections}"/>
</bean>

<!--基於注解的事務管理-->
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    <property name="dataSource" ref="dataSource"/>
</bean>

<tx:annotation-driven transaction-manager="transactionManager"/>


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

<!-- 掃描mybatis映射接口類 -->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
    <property name="basePackage" value="com.test.dsm"/>
    <property name="sqlSessionFactoryBeanName" value="lazySqlSessionFactory"/>
</bean>

這個配置的前提條件是：映射接口類文件(.java)和映射XML文件(.xml)需要放在相同的包下（com.test.dsm）

 

 

如果myBatis映射XML文件和映射接口文件不放在同一個包下怎么辦呢？

如果在不同的包下，那就需要手動配置XML文件的路徑了，只需要修改SqlSessionFactoryBean配置即可：

 

<bean id="lazySqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
    <property name="dataSource" ref="dataSource"/>
    <property name="configLocation" value="classpath:mybatis/mybatis-config.xml"/>
    <!-- 當mybatis的xml文件和mapper接口不在相同包下時，需要用mapperLocations屬性指定xml文件的路徑。
         *是個通配符，代表所有的文件，**代表所有目錄下 -->
    <property name="mapperLocations" value="classpath:com/test/mapper/mysql/**/*.xml" />
</bean>

添加一個mapperLocations屬性，指定加載xml文件的路徑。

 

classpath：表示在classes目錄中查找；

*：通配符表示所有文件；

**：表示所有目錄下；

 

MyBatis官網說明如下：http://mybatis.github.io/spring/factorybean.html

 

Properties

 

SqlSessionFactory has a single required property, the JDBC DataSource . This can be any DataSource and should be configured just like any other Spring database connection.

One common property is configLocation which is used to specify the location of the MyBatis XML configuration file. One case where this is needed is if the base MyBatis configuration needs to be changed. Usually this will be <settings> or <typeAliases> sections.

Note that this config file does not need to be a complete MyBatis config. Specifically, any environments, data sources and MyBatis transaction managers will beignored . SqlSessionFactoryBean creates its own, custom MyBatis Environment with these values set as required.

Another reason to require a config file is if the MyBatis mapper XML files are not in the same classpath location as the mapper classes. With this configuration, there are two options. This first is to manually specify the classpath of the XML files using a <mappers> section in the MyBatis config file. A second option is to use themapperLocations property of the factory bean.

The mapperLocations property takes a list of resource locations. This property can be used to specify the location of MyBatis XML mapper files. The value can contain Ant-style patterns to load all files in a directory or to recursively search all paths from a base location. For example:

<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
  <property name="dataSource" ref="dataSource" />
  <property name="mapperLocations" value="classpath*:sample/config/mappers/**/*.xml" />
</bean>

This will load all the MyBatis mapper XML files in the sample.config.mappers package and its sub-packages from the classpath.