Spring整合Mybatis【Spring基础】

Spring整合Mybatis【Spring基础】

首先导入需要用的maven依赖

    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.2.9.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.6</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.2.9.RELEASE</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.11</version>
        </dependency>

        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>2.0.6</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.18</version>
            <scope>provided</scope>
        </dependency>

    </dependencies>
<!-- 设置项目编码-->
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

编写数据库对应实体类实体类

@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {
    private int id;
    private String name;
    private String pwd;

}

编写查询接口UserMapper

public interface UserMapper {
    public List<User> selectUser();
}

查询xml文件UserMapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.wang.mapper.UserMapper">
    <select id="selectUser" resultType="User">
        select * from mybatis.user;
    </select>
</mapper>

配置mybatis, mybatis-config.xml

<?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>

        <typeAliases>
            <package name = "com.wang.pojo"/>
        </typeAliases>


</configuration>

使用Spring 配置Mybatis, spring-dao.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

    <!--DataSource:使用Spring 的数据源替换mybatis的配置-->
    <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?&amp;useSSL=false&amp;useUnicode=true&amp;characterEncoding=UTF-8&amp;serverTimezone=GMT%2B8"/>
        <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/wang/mapper/*.xml"/>
    </bean>
    <!--SqlSessionTemplate就是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>

编写接口实现类【方式一】

UserMapperImpl

public class UserMapperImpl implements UserMapper {
    //我们的所有操作，都使用sqlSession来执行，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();
    }

}

注册bean，applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
<!--避免过多的配置导致程序混乱，我们把mybatis 配置文件单提出来-->
    <import resource="spring-dao.xml"/>

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

</beans>

测试

public class MyTest {
    @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);
        }

    }
}

方式二

编写接口实现类，UserMapperImpl2

public class UserMapperImpl2 extends SqlSessionDaoSupport implements UserMapper {
    public List<User> selectUser() {

       return getSqlSession().getMapper(UserMapper.class).selectUser();

    }
}

注册bean

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

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

    <bean id="userMapper" class="com.wang.mapper.UserMapperImpl">
        <property name="sqlSession" ref="sqlSession"/>
    </bean>
    
	<!--方式二-->
    <bean id="userMapper2" class="com.wang.mapper.UserMapperImpl2">
        <property name="sqlSessionFactory" ref="sqlSessionFactory"/>
    </bean>
</beans>

测试

public class MyTest {
    @Test
    public void test() throws IOException {

        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
        UserMapper userMapper = context.getBean("userMapper2 ", UserMapper.class);
        for (User user : userMapper.selectUser()) {
            System.out.println(user);
        }

    }
}