Spring整合Mybatis

mybatis的xml配置文件被spring接管

有两种方式：

1.首先导入我们所需要的依赖

<dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.47</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.2</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-->
        <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>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>2.0.2</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.10</version>
        </dependency>
    </dependencies>
<!--确保我们的mapper.xml文件能导出-->
    <build>
        <resources>
            <resource>
                <directory>src/main/resources</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>true</filtering>
            </resource>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>true</filtering>
            </resource>
        </resources>
    </build>

2.创建一个spring-dao.xml文件

这个spring.xml文件可以完全代理我们之前的mybatis的配置文件

<?xml version="1.0" encoding="UTF8"?>
<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"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       https://www.springframework.org/schema/beans/spring-beans.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:org.springframework.jdbc.datasource
    -->
    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=true&amp;useUnicode=true&amp;characterEncoding=UTF8"/>
        <property name="username" value="root"/>
        <property name="password" value="123456"/>
    </bean>

    <!--sqlSessionFactory-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <!--绑定Mybatis配置文件-->
        <property name="configLocation" value="classpath:mybatis-config.xml"/>
        <property name="mapperLocations" value="classpath:com/kang/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,因为他没有set方法-->
        <constructor-arg index="0" ref="sqlSessionFactory"/>
    </bean>

</beans>

可以创建一个applicationContext.xml文件，导入我们所需要的资源配置，这个配置文件可以专门实现我们要执行的功能

    <import resource="spring-dao.xml"/>


    <bean id="UserMapper" class="com.kang.mapper.UserMapperImpl">
        <property name="sqlSession" ref="sqlSession"/>
    </bean>

        <bean id="UserMapper2" class="com.kang.mapper.UserMapperImpl2">
        <property name="sqlSessionFactory" ref="sqlSessionFactory"/>
    </bean>
</beans>

3.将接口的方法直接在一个类中实现，不用去new sqlSession对象了。

• 第一种方式

public class UserMapperImpl implements UserMapper {


    //我们的所有操作，都使用sqlSession来执行，在原来，现在都使用SqlSessionTemplate;
    private SqlSessionTemplate sqlSession;

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


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

• 第二种方式

还有一种更简单的方法：继承SqlSessionDaoSupport，这样我们可以直接获得sqlSession

public class UserMapperImpl2 extends SqlSessionDaoSupport implements UserMapper{
    public List<User> selectUser() {
        return getSqlSession().getMapper(UserMapper.class).selectUser();

    }

4.来测试下这个方法吧

@Test
    public void test() throws IOException {

        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
        UserMapper userMapper = context.getBean("UserMapper", UserMapper.class);
        for (User user : userMapper.selectUser()) {
            System.out.println(user);
        }

看看打印出的结果

User(id=1, name=张三, pwd=123456)
User(id=2, name=李四, pwd=123456)
User(id=3, name=王五, pwd=123456)
User(id=4, name=李五, pwd=123456)

Process finished with exit code 0