spring整合mybatis中mapper扫描的三种方式

Spring扫描Mybatis的mapper接口的配置

1.注意

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.mybatis</groupId>
    <artifactId>mybatis-spring</artifactId>
    <version>new</version>
</dependency>

2. 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：

2.1在applicationContext.xml中使用<mybatis:scan />

<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">
  
   ...
  
    <!-- mybatis -->
   <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="com.zhang.mapper"/>
    
   ...
</beans>

2.2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">
    
   ...
    
    <!-- mybatis -->
   <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="com.zhang.mapper" />
   </bean>
    
   ...
    
</beans>

2.3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("com.zhang.mapper")
public class AppConfig {
  
    @Bean
    public DataSource dataSource() {
        return new PooledDataSource("com.mysql.jdbc.Driver",
                   "jdbc:mysql://localhost:3306/test", "root", "****");
    }
  
    @Bean
    public SqlSessionFactory sqlSessionFactory() throws Exception {
        SqlSessionFactoryBeansessionFactory = new SqlSessionFactoryBean();
        sessionFactory.setDataSource(dataSource());
        return sessionFactory.getObject();
    }
}
//若使用springboot则可以将@MapperScan()打在springboot主启动类上面

Spring配置扫描mybatis的mapper文件注意

一般会将业务的mapper文件放到不同的包中：

但如果在不同包中需要下面的配置

spring配置扫描就需要配置下面的方式（两个）：

<!-- mybatis文件配置，扫描所有mapper文件 -->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"
        p:dataSource-ref="dataSource" p:configLocation="classpath:conf/mybatis-config.xml"
        p:mapperLocations="classpath:mapper/**/*.xml" />