1导包

<dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
        <!--下面是spring的jar-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.8.10</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aspects</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <!--mybatis-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.4.5</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>1.3.1</version>
        </dependency>

        <!--数据源-->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.4</version>
        </dependency>

        <!--mysql-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.30</version>
        </dependency>
    </dependencies>

2spring-mybatis.xml

<!--开启组建扫描-->
    <context:component-scan base-package="service所在的包"/>

    <!--加载properties配置文件-->
    <context:property-placeholder location="数据库配置文件"/>

    <bean class="com.alibaba.druid.pool.DruidDataSource" id="dataSource">
        <property name="driverClassName" value="${jdbc.driverClassName}"/>
        <property name="url" value="${jdbc.url}"/>
        <property name="username" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
    </bean>

    <!--配置SqlSessionFactory-->
    <bean class="org.mybatis.spring.SqlSessionFactoryBean" id="sessionFactory">
        <!--数据源-->
        <property name="dataSource" ref="dataSource"/>
        <!--扫描mapper文件-->
        <property name="mapperLocations" value="mapper xml文件所在目录"/>
        <!--配置别名，可有可无-->
        <property name="typeAliasesPackage" value="实体类所在目录"/>
        <!--加载配置文件，可有可无-->
        <!--<property name="configLocation" value="mybatis配置文件"/>-->
    </bean>

    <!--配置MapperScannerConfigurer：用来扫描mapper接口，并且创建接口的实现类 -->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer" id="mapperScannerConfigurer">
        <!--注入sqlSessionFactory-->
        <property name="sqlSessionFactoryBeanName" value="sessionFactory"/>
        <!--扫描某个包下的接口-->
        <property name="basePackage" value="实体类包名"/>
    </bean>

3dao层

public interface UserDao {
   public User selectUserById(Integer uid);
}

service层

@Service //创建对象
public class UserServiceImpl implements IUserService {
   @Autowired //注入userdao的实现类
   private UserDao userDao;

   public User selectUserById(Integer uid) {
       return userDao.selectUserById(uid);
   }
}

5、测试类

   public void testSelectUserById(){
       ClassPathXmlApplicationContext context=new ClassPathXmlApplicationContext("spring-mybatis.xml");
       IUserService service = context.getBean(UserServiceImpl.class);
       User user = service.selectUserById(3);
       System.out.println(user);
   }