mybatis和spring整合

第一种方法

1.需要导入的包：

pom.xml:

   
<dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.11</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>5.1.9.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.3.14</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>2.0.6</version>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>RELEASE</version>
            <scope>compile</scope>
        </dependency>
    </dependencies>

    <build>
        <resources>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.xml</include>
                </includes>
                <filtering>false</filtering>
            </resource>
        </resources>
    </build>

2.回忆Mybatis

• 编写实体类
• 编写核心配置文件
• 编写接口
• 编写Mapper.xml
• 测试

3.Mybatis-Spring

UserMapper接口：

package com.kakafa.mapper;
import com.kakafa.pojo.User;
import java.util.List;

public interface UserMapper {

        public List<User> selectUser();

}

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.kakafa.mapper.UserMapper">

    <select id="selectUser" resultType="user">
        select * from mybatistest.user;
    </select>

</mapper>

UserMapperImpl:

package com.kakafa.mapper;
import com.kakafa.pojo.User;
import org.mybatis.spring.SqlSessionTemplate;
import java.util.List;

public class UserMapperImpl implements UserMapper{

    //我们所有操作都使用sqlSession来执行,现在都使用sqlSessionTemplate,因为习惯用sqlSession，所以这里命名为sqlSession
    private SqlSessionTemplate sqlSession;

    //需要有set方法才能够在spring的bean注册中注入sqlSession的值-通过set方法注入：<property name="sqlSession" ref="sqlSession"/>
    public void setSqlSession(SqlSessionTemplate sqlSession) {
        this.sqlSession = sqlSession;
    }

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

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>

    <!--下面这个别名其实也可以在Spring的配置文件里配-->
    <typeAliases>
        <package name="com.kakafa.pojo"/>
    </typeAliases>


</configuration>

spring-dao.xml:spring配置文件，把mybatis配置整合到spring配置中

<?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的数据源来替换mybatis的数据源配置-->
    <!--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/mybatistest?useSSL=false&amp;useUnicode=true&amp;CharacterEncoding=UTF8&amp;serverTimezone=GMT"/>
        <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/kakafa/mapper/UserMapper.xml"/>
    </bean>

    <!--sqlSessionTemplate就是我们使用的sqlSession-->
    <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
        <!--因为org.mybatis.spring.SqlSessionTemplate这个类里没有set方法，所以只能利用构造器注入-->
        <constructor-arg index="0" ref="sqlSessionFactory"/>
    </bean>

    <bean id="userMapperImpl" class="com.kakafa.mapper.UserMapperImpl">
        <!--这里是set方法注入-->
        <property name="sqlSession" ref="sqlSession"/>
    </bean>

</beans>

test:

import com.kakafa.mapper.UserMapper;
import com.kakafa.pojo.User;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import java.io.IOException;
import java.util.List;

public class MyTest {

    @Test
    public void test() throws IOException {

        ApplicationContext context = new ClassPathXmlApplicationContext("spring-dao.xml");
        UserMapper mapper = context.getBean("userMapperImpl",UserMapper.class);
        List<User> users = mapper.selectUser();

        for (User user : users) {
            System.out.println(user);
        }

    }
}

第二种方法：简化了第一种方法

UserMapperImpl2:

package com.kakafa.mapper;
import com.kakafa.pojo.User;
import org.apache.ibatis.session.SqlSession;
import org.mybatis.spring.support.SqlSessionDaoSupport;
import java.util.List;

public class UserMapperImpl2 extends SqlSessionDaoSupport implements UserMapper{

    @Override
    public List<User> selectUser() {

        SqlSession sqlSession = getSqlSession();
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        List<User> users = mapper.selectUser();
        return users;
    }
}

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的数据源来替换mybatis的数据源配置-->
    <!--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/mybatistest?useSSL=false&amp;useUnicode=true&amp;CharacterEncoding=UTF8&amp;serverTimezone=GMT"/>
        <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/kakafa/mapper/UserMapper.xml"/>
    </bean>


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

</beans>