Spring整合Mybatis

Spring整合Mybatis

导入依赖

<dependencies>
    
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.38</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
    <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>5.3.13</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>
    
	<!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.3.13</version>
        </dependency>

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13.2</version>
            <scope>test</scope>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.aspectj/aspectjweaver -->
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.9.7</version>
        </dependency>
</dependencies>

---

使用Spring创建SqlSessionTemplate对象(用途和SqlSession一样)

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

    <!-- 使用Spring的数据源替换Mybatis的配置 -->
    <bean id="datasource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="url"
                  value="jdbc:mysql://localhost:3306/mybatis?useSSL=false&amp;useUnicode=true&amp;characterEncoding=utf8"/>
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="username" value="root"/>
        <property name="password" value="123456"/>
    </bean>

    <!--SqlSessionFactory-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!--数据库配置-->
        <property name="dataSource" ref="datasource"/>
        <!--绑定Mybatis配置文件-->
        <property name="configLocation" value="mybatis-config.xml"/>
        <!--绑定映射-->
        <property name="mapperLocations" value="com/mybatis/mapper/*.xml"/>
    </bean>

    <!--SqlSessionTemplate：就是以前使用的sqlSession-->
    <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
        <!--因为源码没有set方法，所以使用有参构造-->
        <constructor-arg index="0" ref="sqlSessionFactory"/>
    </bean>

</beans>

整合到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"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="
            http://www.springframework.org/schema/beans
            http://www.springframework.org/schema/beans/spring-beans.xsd
            http://www.springframework.org/schema/aop
            http://www.springframework.org/schema/aop/spring-aop.xsd">

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

    <!--将SqlSessionTemplate注入实现类-->
    <bean id="UserMapperImpl" class="com.mybatis.mapper.impl.UserMapperImpl">
        <!--注入SqlSessionTemplate(需要创建)-->
        <property name="sqlSession" ref="sqlSession"/>
    </bean>

    <bean id="UserMapperImpl2" class="com.mybatis.mapper.impl.UserMapperImpl2">
        <!--注入SqlSessionFactory(不用创建SqlSessionTemplate)-->
        <property name="sqlSessionFactory" ref="sqlSessionFactory"/>
    </bean>

</beans>

此时可以留着mybatis-config.xml做一些简单配置

<?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>

    <!--起别名-->
    <typeAliases>
        <package name="com.mybatis.beans"/>
    </typeAliases>

</configuration>

---

实体类

public class User {
    private int id;
    private String name;
    private String pwd;

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", pwd='" + pwd + '\'' +
                '}';
    }

    public User() {
    }

    public User(int id, String name, String pwd) {
        this.id = id;
        this.name = name;
        this.pwd = pwd;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPwd() {
        return pwd;
    }

    public void setPwd(String pwd) {
        this.pwd = pwd;
    }
}

接口

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

接口的映射文件

<?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.mybatis.mapper.UserMapper">

    <select id="selectAllUsers" resultType="User">
        select *
        from `user`;
    </select>
</mapper>

方式一

接口实现类

public class UserMapperImpl implements UserMapper {

    private SqlSessionTemplate sqlSession;

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

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

        List<User> users = mapper.selectAllUsers();
        return users;
    }
}

方式二（继承 SqlSessionDaoSupport）

public class UserMapperImpl2 extends SqlSessionDaoSupport implements UserMapper {

    @Override
    public List<User> selectAllUsers() {
        UserMapper mapper = getSqlSessionTemplate().getMapper(UserMapper.class);

        List<User> users = mapper.selectAllUsers();
        return users;
    }
}

测试类

public class MyTest {
    @Test
    public void test01() {
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");

        UserMapper userMapper = context.getBean("UserMapperImpl", UserMapperImpl.class);

        List<User> users = userMapper.selectAllUsers();
        for (User user : users) {
            System.out.println(user);
        }
    }

    @Test
    public void test02() {
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");

        UserMapper userMapper = context.getBean("UserMapperImpl2", UserMapperImpl2.class);

        List<User> users = userMapper.selectAllUsers();
        for (User user : users) {
            System.out.println(user);
        }
    }
}