Spring扫描Mybatis的mapper接口的三种配置方式

• mybatis支持与spring结合使用，使得mybatis中的mapper接口可以作为spring容器中的bean被应用代码中相关类，如Service类，通过@Autowired自动注入进来。在使用方面需要在项目中引入以下包：

  <dependency>
      <groupId>org.mybatisgroupId>
      <artifactId>mybatis-springartifactId>
      <version>1.3.1version>
  dependency>
  

• 在spring中可以通过三种方式来自动扫描获取应用代码的mybatis相关的mapper接口定义：

1. 在applicationContext.xml中使用

   <beans xmlns="http://www.springframework.org/schema/beans"
      xmlns:context="http://www.springframework.org/schema/context"
      xmlns:tx="http://www.springframework.org/schema/tx"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="
      http://www.springframework.org/schema/beans     
      http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
      http://www.springframework.org/schema/context 
      http://www.springframework.org/schema/context/spring-context-3.0.xsd
      http://www.springframework.org/schema/tx
      http://www.springframework.org/schema/tx/spring-tx-3.0.xsd">
      
      ...
      
       
      <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
      		<property name="dataSource" ref="dataSource" />
      		<property name="mapperLocations" value="classpath:mybatis/mapper/**/*.xml" />
      		<property name="configLocation" value="classpath:mybatis/mybitas-config.xml" />
      bean>
      
      <mybatis:scan base-package="org.xyz.jblog.dao"/>
      
      ...
      
   beans>
   

2. 在applicationContext.xml中使用bean标签注册MapperScannerConfigurer，即

   <beans xmlns="http://www.springframework.org/schema/beans"
      xmlns:context="http://www.springframework.org/schema/context"
      xmlns:tx="http://www.springframework.org/schema/tx"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="
      http://www.springframework.org/schema/beans     
      http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
      http://www.springframework.org/schema/context 
      http://www.springframework.org/schema/context/spring-context-3.0.xsd
      http://www.springframework.org/schema/tx
      http://www.springframework.org/schema/tx/spring-tx-3.0.xsd">
      
      ...
      
       
      <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
      		<property name="dataSource" ref="dataSource" />
      		<property name="mapperLocations" value="classpath:mybatis/mapper/**/*.xml" />
      		<property name="configLocation" value="classpath:mybatis/mybitas-config.xml" />
      bean>
      
      <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
      		<property name="basePackage" value="org.xyz.jblog.dao" />
      bean>
      
      ...
      
   beans>
   

3. 如果应用是使用Java配置方式而不是XML，则在@Configuration配置类使用@MapperScan或者@MapperScans注解：

   @Configuration
   @MapperScan("org.xyz.jblog.dao")
   public class AppConfig {
       @Bean
       public DataSource dataSource() {
           return new PooledDataSource("com.mysql.jdbc.Driver", "jdbc:mysql://localhost:3306/test", "root", "root");
       }
       @Bean
       public SqlSessionFactory sqlSessionFactory() throws Exception {
           SqlSessionFactoryBeansessionFactory = new SqlSessionFactoryBean();
           sessionFactory.setDataSource(dataSource());
           return sessionFactory.getObject();
       }
   }