Spring：整合MyBatis

Spring整合MyBatis

• 导入所需要的依赖（Maven）

  <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>5.2.9.RELEASE</version>
        </dependency>

        <!--spring-jdbc-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.2.9.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.9.4</version>
        </dependency>

        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>2.0.5</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.16.10</version>
        </dependency>


    </dependencies>

<!--开放对xml静态文件的权限-->
    <build>
        <resources>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.xml</include>
                </includes>
                <filtering>true</filtering>
            </resource>
        </resources>
    </build>

• 配置Mybatis的配置文件（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>

    <!--别名-->
    <typeAliases>
        <package name="com.ht.pojo"/>
    </typeAliases>

    <!--配置-->

</configuration>

• 导入数据库，书写mapper接口及配置文件

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

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.ht.mapper.UserMapper">

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

• spring-dao配置文件（获取数据源，SqlSessionFactoryBean，SqlSessionTemlate...）

<?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 jdbc、 c3p0.. -->
    <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"/>
        <property name="username" value="root"/>
        <property name="password" value="123456"/>
    </bean>

    <!--sqlSessionFactory 配置-->
    <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="com/ht/mapper/*.xml"/>
    </bean>

    <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
        <!--构造器注入-->
        <constructor-arg index="0" ref="sqlSessionFactory"/>
    </bean>

</beans>

• 【区别于MyBatis】书写mapper接口的实现类，并将SqlSessionTemplate作为类的私有属性，通过set注入

package com.ht.mapper;

import com.ht.pojo.User;
import org.mybatis.spring.SqlSessionTemplate;

import java.util.List;

public class UserMapperImpl implements UserMapper{
    // 所有操作都使用 sqlSessionTemplate
    private SqlSessionTemplate sqlSession;

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

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

• spring 配置文件 引入 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">

    <!--引入 mybatis 实现-->
    <import resource="spring-dao.xml"/>

    <!--注入 mapper 的实现类-->
    <bean id="userMapper" class="com.ht.mapper.UserMapperImpl">
        <property name="sqlSession" ref="sqlSession"/>
    </bean>

</beans>

• 测试：通过spring容器中的 mapper实现类对象 访问数据库内容

public static void main(String[] args){
        ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
        UserMapperImpl userMapper = context.getBean("userMapper", UserMapperImpl.class);
        List<User> users = userMapper.selectUser();
        for (User user:users) {
            System.out.println(user.toString());
        }
}