import com.alibaba.druid.pool.DruidDataSource;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.transaction.annotation.EnableTransactionManagement;
​
import javax.sql.DataSource;
​
​
@Configuration  //配置类
@PropertySource("classpath:db2.properties") //加载属性文件peoperties
@ComponentScan(basePackages = "com.czxy.demo17_accountSW")  //扫描所需要的包
@EnableTransactionManagement  //开启事务
public class SpringConfiguration {
    @Value("${jdbc.driver}")
    private String driver;
    @Value("${jdbc.url}")
    private String url ;
    @Value("${jdbc.username}")
    private String username;
    @Value("${jdbc.password}")
    private String password;
​
    @Bean
    public DataSource dataSource(){
        DruidDataSource druidDataSource = new DruidDataSource();
        druidDataSource.setDriverClassName(driver);
        druidDataSource.setUrl(url);
        druidDataSource.setUsername(username);
        druidDataSource.setPassword(password);
​
        return druidDataSource;
    }
    //事务管理器【管理事务，事务出现异常会进行回滚事务】
    @Bean
    public DataSourceTransactionManager dataSourceTransactionManager(DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }
}

import com.github.pagehelper.PageHelper;
import org.apache.ibatis.plugin.Interceptor;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
​
import tk.mybatis.spring.mapper.MapperScannerConfigurer;
​
import javax.sql.DataSource;
import java.util.Properties;
​
@Configuration   //配置类
public class MyBatisConfiguration {
​
    @Bean
    public SqlSessionFactory sqlSessionFactory(DataSource dataSource) throws Exception {
        //1 创建工厂
        // 1.通过工厂bean创建对象，最后需要调用 getObject()获得具体的对象
        SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
​
        //2 设置数据-- SqlMapConfig.xml 配置信息
​
        // 1.1 设置数据源
        factoryBean.setDataSource(dataSource);
        // 1.2 设置别名包扫描
        factoryBean.setTypeAliasesPackage("要加载的daomain包的全路径");
        // 1.3 全局配置：驼峰映射
        org.apache.ibatis.session.Configuration config = new org.apache.ibatis.session.Configuration();
        config.setMapUnderscoreToCamelCase(true);
        factoryBean.setConfiguration(config);
​
        // 2 插件配置
        // 2.1 分页插件
        PageHelper pageHelper = new PageHelper();
        Properties pageProps = new Properties();
        pageProps.setProperty("dialect", "mysql");
        pageProps.setProperty("rowBoundsWithCount", "true");
        pageHelper.setProperties(pageProps);
        factoryBean.setPlugins(new Interceptor[] { pageHelper });
​
​
        // 返回SqlSessionFactory
        return factoryBean.getObject();
    }
​
    /**
     * 扫描Dao的包，查找各种XxxMapper接口，创建好UserMapper等对象存入到IOC的容器中
     * @return
     */
    @Bean
    public MapperScannerConfigurer mapperScanner() {
        MapperScannerConfigurer configurer = new MapperScannerConfigurer();
​
​
        configurer.setBasePackage("要加载的mapper包的全路径");
        return configurer;
    }
}

jdbc.driver=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/连接数据库，要访问的数据库的库名
jdbc.username=数据库用户名【一般都是root】
jdbc.password=数据库密码【一般都是1234】

public interface UserService {
    //查询所有
    List<User> selectAll();
}
​

@Service(value = "userService1") 
public class UserServiceImpl implements UserService {    
//依赖注入mapper    
@Resource    
private UserMapper userMapper;​   
//查询所有    
@Override    
public List<User> selectAll() {       
 return userMapper.selectAll();   
} 
}

import javax.persistence.Id;
import javax.persistence.Table;
​
@Table(name = "user")
public class User {
    @Id
​
    private Integer id ;
    private String name ;
    private Integer age ;
    private Double num ;
    //省略构造和set/get方法
}

@RunWith(SpringRunner.class)
@ContextConfiguration(classes = {SpringConfiguration.class, MyBatisConfiguration.class})
public class TestSM {
​
    @Resource(name = "userService1")
    private UserService userServiceImpl;
​
    @Test
    public void testDemo16(){
        List<User> list= userServiceImpl.selectAll();
        list.forEach(System.out::println);
    }
}