Spring整合MyBatis

推荐先阅读：Spring全家桶

依赖：

<dependency>
    <!--Spring操作数据库需要该jar包-->
    <groupId>org.springframework</groupId>
    <artifactId>spring-jdbc</artifactId>
    <version>5.2.10.RELEASE</version>
</dependency>
<dependency>
    <!--
	Spring与Mybatis整合的jar包
	这个jar包mybatis在前面，是Mybatis提供的
	-->
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis-spring</artifactId>
    <version>1.3.0</version>
</dependency>

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/spring_db?useSSL=false
jdbc.username=root
jdbc.password=root

数据源配置类

public class JdbcConfig {
    @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 ds = new DruidDataSource();
        ds.setDriverClassName(driver);
        ds.setUrl(url);
        ds.setUsername(userName);
        ds.setPassword(password);
        return ds;
    }
}

Mybatis配置类

public class MybatisConfig {
    //定义bean，SqlSessionFactoryBean，用于产生SqlSessionFactory对象
    @Bean
    public SqlSessionFactoryBean sqlSessionFactory(DataSource dataSource){
        SqlSessionFactoryBean ssfb = new SqlSessionFactoryBean();
        //设置模型类的别名扫描
        ssfb.setTypeAliasesPackage("com.zx.domain");
        //设置数据源
        ssfb.setDataSource(dataSource);
        return ssfb;
    }
    //定义bean，返回MapperScannerConfigurer对象
    @Bean
    public MapperScannerConfigurer mapperScannerConfigurer(){
        MapperScannerConfigurer msc = new MapperScannerConfigurer();
        msc.setBasePackage("com.zx.dao");
        return msc;
    }
}

SpringConfig主配置类，并且import数据源配置类、Mybatis配置类

//配置类注解
@Configuration
//包扫描
@ComponentScan("com.zx")
// 读properties
@PropertySource("classpath:jdbc.properties")
@Import({JdbcConfig.class,MybatisConfig.class})
public class SpringConfig {
}

主程序

public class App {
    public static void main(String[] args) {
        ApplicationContext ctx = new AnnotationConfigApplicationContext(SpringConfig.class);

        AccountService accountService = ctx.getBean(AccountService.class);

        Account ac = accountService.findById(1);
        System.out.println(ac);
    }
}

拓展：配置演变

从xml文件 –> 注解+配置类

xml版本：

create database spring_db character set utf8;
use spring_db;
create table tbl_account(
    id int primary key auto_increment,
    name varchar(35),
    money double
);

<dependencies>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <version>5.2.10.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>druid</artifactId>
        <version>1.1.16</version>
    </dependency>
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.5.6</version>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.47</version>
    </dependency>
</dependencies>

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/spring_db?useSSL=false
jdbc.username=root
jdbc.password=root

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    // 初始化属性数据
    <!--读取外部properties配置文件-->
    <properties resource="jdbc.properties"></properties>
    // 初始化类型别名
    <!--别名扫描的包路径-->
    <typeAliases>
        <package name="com.zx.domain"/>
    </typeAliases>
    // 初始化dataSource
    <!--数据源-->
    <environments default="mysql">
        <environment id="mysql">
            <transactionManager type="JDBC"></transactionManager>
            <dataSource type="POOLED">
                <property name="driver" value="${jdbc.driver}"></property>
                <property name="url" value="${jdbc.url}"></property>
                <property name="username" value="${jdbc.username}"></property>
                <property name="password" value="${jdbc.password}"></property>
            </dataSource>
        </environment>
    </environments>
    // 初始化映射配置
    <!--映射文件扫描包路径-->
    <mappers>
        <package name="com.zx.dao"></package>
    </mappers>
</configuration>

public class App {
    public static void main(String[] args) throws IOException { 
    	// 1. 创建SqlSessionFactoryBuilder对象
        SqlSessionFactoryBuilder sqlSessionFactoryBuilder = new SqlSessionFactoryBuilder();
        // 2. 加载SqlMapConfig.xml配置文件
        InputStream inputStream = Resources.getResourceAsStream("SqlMapConfig.xml.bak");
        // 3. 创建SqlSessionFactory对象
        SqlSessionFactory sqlSessionFactory = sqlSessionFactoryBuilder.build(inputStream);

        // 获取连接，获取实现
        // 4. 获取SqlSession
        SqlSession sqlSession = sqlSessionFactory.openSession();
        // 5. 执行SqlSession对象执行查询，获取结果User
        AccountDao accountDao = sqlSession.getMapper(AccountDao.class);

        // 获取数据层接口
        Account ac = accountDao.findById(1);
        System.out.println(ac);

        // 关闭接口
        // 6. 释放资源
        sqlSession.close();
    }
}