Spring_整合Mybatis

12 整合Mybatis

步骤：

1.导入相关jar包

• junit

• mybatis

• mysql数据库

• spring

• aop织入

• mybatis-spring【new】

    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>3.8.2</version>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.22</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.5</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.3.2</version>
        </dependency>
        <!--Spring操作数据库的话，还需要一个spring-jdbc-->
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.3.2</version>
        </dependency>
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.9.6</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis-spring -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>2.0.6</version>
        </dependency>
    </dependencies>

2.编写配置文件

 

3.测试

 

12.1 回忆Mybatis

1.编写实体类

2.编写核心配置文件

3.编写接口

4.编写Mapper.xml

5.测试

 

12.2 Mybatis-Spring

1.编写数据源配置

2.SQLSessionFactory

3.SqlSessionTemplate

4.给接口加实现类

public class UserMapperImpl implements UserMapper {

    // 之前，我们所有的操作都是使用SqlSession来执行
    // 现在，都使用SqlSessionTemplate
    private SqlSessionTemplate sqlSession;

    public void setSqlSession(SqlSessionTemplate sqlSession) {
        this.sqlSession = sqlSession;
    }

    @Override
    public List<User> getAllUser() {
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        return mapper.getAllUser();
    }
}

SqlSessionDaoSupport 是一个抽象的支持类，用来为你提供 SqlSession。调用 getSqlSession() 方法你会得到一个 SqlSessionTemplate，之后可以用于执行 SQL 方法，就像下面这样:

public class UserMapperImpl2 extends SqlSessionDaoSupport implements UserMapper {
    @Override
    public List<User> getAllUser() {
        return getSqlSession().getMapper(UserMapper.class).getAllUser();
    }
}public class UserMapperImpl2 extends SqlSessionDaoSupport implements UserMapper {
    @Override
    public List<User> getAllUser() {
        return getSqlSession().getMapper(UserMapper.class).getAllUser();
    }
}

在这个类里面，通常更倾向于使用 MapperFactoryBean，因为它不需要额外的代码。但是，如果你需要在 DAO 中做其它非 MyBatis 的工作或需要一个非抽象的实现类，那么这个类就很有用了。

SqlSessionDaoSupport 需要通过属性设置一个 sqlSessionFactory 或 SqlSessionTemplate。如果两个属性都被设置了，那么 SqlSessionFactory 将被忽略。

假设类 UserMapperImpl 是 SqlSessionDaoSupport 的子类，可以编写如下的 Spring 配置来执行设置：

<bean id="userMapperImpl2" class="com.gazikel.mapper.UserMapperImpl2">
    <property name="sqlSessionFactory" ref="sqlSessionFactory"/>
</bean>

5.测试

@Test
public void test2() {
    ApplicationContext context = new ClassPathXmlApplicationContext("spring-dao.xml");

    UserMapper userMapper = context.getBean("userMapper", UserMapper.class);
    List<User> userList = userMapper.getAllUser();
    for (User user : userList) {
        System.out.println(user);
    }
}

<?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:aop="http://www.springframework.org/schema/aop"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        https://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/aop
        https://www.springframework.org/schema/aop/spring-aop.xsd">

    <!--DataSource:使用Spring的数据源替换Mybatis的配置  c3p0 dbcp druid
        我们这里使用Spring提供的JDBC-->
    <bean id="datasource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.cj.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://localhost:3306/mybatis?characterEncoding=utf8&amp;serverTimezone=UTC"/>
        <property name="username" value="root"/>
        <property name="password" value="123456"/>
    </bean>

    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="datasource"></property>
        <!--绑定Mybatis配置文件-->
        <property name="configLocation" value="classpath:mybatis-config.xml"></property>
        <property name="mapperLocations" value="classpath:com/gazikel/mapper/*.xml"/>
    </bean>

    <!--SqlSessionTemplate: 就是我们使用的SqlSession-->
    <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
        <!--只能使用构造器注入SqlSessionFactory，因为它没有set方法-->
        <constructor-arg index="0" ref="sqlSessionFactory"/>
    </bean>

    <bean id="userMapper" class="com.gazikel.mapper.UserMapperImpl">
        <property name="sqlSession" ref="sqlSession"/>
    </bean>
</beans>