代码层次
整合
mybatis:dao层,操作数据库,需要单例的SqlSessionFactory工厂。
spring:容器,管理对象。
可以将SqlSessionFactory、事务、连接池以及mapper的动态代理交给spring来做。
applicationContext.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/spring-aop.xsd">
<!--加载外部资源文件-->
<context:property-placeholder location="classpath:db.properties"/>
<!--数据库连接池-->
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<property name="driverClass" value="${jdbc.driver}"></property>
<property name="jdbcUrl" value="${jdbc.url}"></property>
<property name="user" value="${jdbc.username}"></property>
<property name="password" value="${jdbc.password}"></property>
</bean>
<!--配置SqlSessionFactory,通过Spring来管理会话工厂-->
<bean id="SqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<!--配置数据源:因为要使用SqlSession操作数据库-->
<property name="dataSource" ref="dataSource"></property>
<!--加载mybatis的全局配置文件-->
<!--<property name="configLocation" value="classpath:mybatis.xml"></property>-->
<!--Spring起别名-->
<property name="typeAliasesPackage" value="com.me.pojo"></property>
</bean>
<!--mapper动态代理 通过扫描批量加载mapper接口来创建代理bean,这些bean的名字是接口名字(首字母小写)-->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<!--指定mapper接口的包路径-->
<property name="basePackage" value="com.me.mapper"/>
</bean>
<!--注解扫描-->
<context:component-scan base-package="com.me.service"></context:component-scan>
</beans>
UsersService.java
public interface UsersService {
public Users selectById(int id);
}
UsersServiceImpl
@Service("userService")
public class UsersServiceImpl implements UsersService {
@Autowired
private UsersMapper usersMapper;
@Override
public Users selectById(int id) {
return usersMapper.selectById(id);
}
}
测试类
public class AppTest {
@Test
public void selectById(){
ApplicationContext applicationContext=new ClassPathXmlApplicationContext("applicationContext.xml");
UsersService usersService= (UsersService) applicationContext.getBean("userService");
Users user=usersService.selectById(1);
System.err.println(user.getUsername());
}
}