最新Spring整合MyBatis详解教程

淩亂°似流年 2022-11-26 09:54 193阅读 0赞

### 目录 ###

*  1、导入相关jar包
 *   *  1. junit
     *  2. mybatis
     *  3. mysql
     *  4. spring相关
     *  5. aop织入
     *  6. mybatis-spring
     *  7. lombok（选用）
 *  2、回顾：建立一个Mybatis程序
 *   *  1. IDEA连接数据库
     *  2. 编写MyBatis核心配置文件
     *  3. 创建数据库表对应实体类
     *  4. 编写Mapper接口
     *  5. 编写Mapper.xml配置文件
     *  6. 编写测试类
     *  7. 给Mapper.xml添加注册
     *  8. 测试运行
 *  3、spring整合：方式一
 *   *  1. 引入spring配置文件
     *  2. 使用Spring的数据源替换MyBatis的数据源配置
     *  3. 通过spring创建sqlSessionFactory
     *  4. 创建sqlSession对象
     *  5. 新建接口实现类
     *  6. 创建实现类对象
     *  7. 修改测试类
     *  8. 运行测试
 *  4、spring整合：方式二
 *   *  1. 新建接口实现类
     *  2. 创建接口实现类对象
     *  3. 修改测试类
     *  4. 测试运行

--------------------

![image-20200811201331833][]

`mybatis-spring官方文档`：http://mybatis.org/spring/zh/index.html

> 首先新建一个空的maven项目

# 1、导入相关jar包 #

--------------------

## 1. junit ##

<dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.13</version>
        <scope>test</scope>
    </dependency>

## 2. mybatis ##

<dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.5.5</version>
    </dependency>

## 3. mysql ##

<dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.21</version>
    </dependency>

## 4. spring相关 ##

<dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>5.2.8.RELEASE</version>
    </dependency>
    
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jdbc</artifactId>
        <version>5.1.3.RELEASE</version>
    </dependency>

## 5. aop织入 ##

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

## 6. mybatis-spring ##

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

## 7. lombok（选用） ##

<dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <version>1.18.12</version>
    </dependency>

--------------------

最后为了防止`maven配置文件无法被导出或生效`，加入以下代码

<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、回顾：建立一个Mybatis程序 #

**更详细过程可以看我之前的博客**：[第一个MyBatis程序][MyBatis]

--------------------

## 1. IDEA连接数据库 ##

**大家连接自己的数据库即可，这里的实验表格为**：  
![image-20200811181559385][]

## 2. 编写MyBatis核心配置文件 ##

![image-20200811181900880][]

<?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>
        <environments default="development">
            <environment id="development">
                <transactionManager type="JDBC"/>
                <dataSource type="POOLED">
                    <property name="driver" value="com.mysql.jdbc.Driver"/>
                    <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSH=true&useUnicode=true&characterEncoding=UTF-8"/>
                    <property name="username" value="root"/>
                    <property name="password" value="200024"/>
                </dataSource>
            </environment>
        </environments>
    </configuration>

## 3. 创建数据库表对应实体类 ##

![image-20200811181927962][]

package pojo;
    
    import lombok.Data;
    
    @Data
    public class User { 
        private int id;
        private String name;
        private String pwd;
    }

## 4. 编写Mapper接口 ##

![image-20200811182020272][]

package mapper;
    
    import pojo.User;
    
    import java.util.List;
    
    public interface UserMapper { 
        public List<User> getUser();
    }

## 5. 编写Mapper.xml配置文件 ##

![image-20200811182204453][]

<?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="mapper.UserMapper">
        <select id="getUser" resultType="pojo.User">
            select * from mybatis.user
        </select>
    </mapper>

## 6. 编写测试类 ##

![image-20200811182242082][]

public class Test { 
        @org.junit.Test
        public void test() throws IOException { 
            String resource = "mybatis-config.xml";
            InputStream in = Resources.getResourceAsStream(resource);
            SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(in);
            SqlSession sqlSession = sessionFactory.openSession(true);
            UserMapper mapper = sqlSession.getMapper(UserMapper.class);
            List<User> users = mapper.getUser();
            for (User user : users) { 
                System.out.println(user);
            }
        }
    }

## 7. 给Mapper.xml添加注册 ##

在核心配置文件`mybatis-config.xml`中加入以下代码

## 8. 测试运行 ##

![image-20200811194703348][]

到此，mybatis程序的创建已成功，接下来将进行修改，整合spring

# 3、spring整合：方式一 #

**通过SqlSessionTemplate创建SqlSession**

--------------------

> 接下来将在上述实验环境下进行修改

## 1. 引入spring配置文件 ##

在`resource`目录下新建`spring-dao.xml`  
![image-20200811183008850][]

<?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 https://www.springframework.org/schema/beans/spring-beans.xsd">
    
    </beans>

## 2. 使用Spring的数据源替换MyBatis的数据源配置 ##

> 在`spring配置文件`中加入以下代码，配置**数据源信息**

<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?useSSH=true&useUnicode=true&characterEncoding=UTF-8"/>
        <property name="username" value="root"/>
        <property name="password" value="200024"/>
    </bean>

此时，就可以删除mybatis核心配置文件`mybatis-config.xml`中的数据源配置  
![image-20200811184444369][]

## 3. 通过spring创建sqlSessionFactory ##

*  在 **MyBatis** 中，是通过 `SqlSessionFactoryBuilder` 来创建 `SqlSessionFactory`
 *  而在 **MyBatis-Spring** 中，则使用 `SqlSessionFactoryBean` 来创建

--------------------

> 在`spring配置文件`中加入以下代码，创建`sqlSessionFactory`

<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
    </bean>

**唯一的必要属性**：用于 JDBC 的 `DataSource`，注入上述创建好的`数据源`

**还可以配置其他属性**，完全取代`mybatis-config.xml`中的配置  
![image-20200811185806672][]  
**这里加入两个属性配置**：

*  `configLocation`：指定mybatis的xml配置文件路径
 *  `mapperLocations`：注册Mapper.xm映射器

<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        
        <property name="configLocation" value="classpath:mybatis-config.xml"/>
        
        <property name="mapperLocations" value="classpath:mapper/*.xml"/>
    </bean>

这里，我们在`spring配置文件`中注册了`Mapper.xml`，就可以删除`mybatis-config.xml`中的`Mapper.xml`的注册  
![image-20200811185526572][]

## 4. 创建sqlSession对象 ##

*  在mybatis中，`SqlSession` 提供了在数据库执行 SQL 命令所需的所有方法
 *  而在spring-mybatis，没有`SqlSession`了，而是`SqlSessionTemplate`，这两个是同一个东西

--------------------

> 在`spring配置文件`中加入以下代码，创建`sqlSession`

*  这里使用上述创建好的`sqlSessionFactory` 作为构造方法的参数来创建 `SqlSessionTemplate` 对象。

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

## 5. 新建接口实现类 ##

> 上一步我们创建了`sqlSession`对象，此时需要创建一个类来使用`sqlSession`

![image-20200811191543680][]

在该类中添加一个 `SqlSession` 属性，并添加 `set方法` 用于后续sqlSession的注入

public class UserMapperImpl implements UserMapper { 
        //原来所有操作都通过SqlSession来执行，现在都是SqlSessionTemplate
        private SqlSessionTemplate sqlSession;
    
        public void setSqlSession(SqlSessionTemplate sqlSession) { 
            this.sqlSession = sqlSession;
        }
    
        public List<User> getUser() { 
            UserMapper mapper = sqlSession.getMapper(UserMapper.class);
            return mapper.getUser();
        }
    }

## 6. 创建实现类对象 ##

> 利用spring创建上述接口实现类对象，取名为`userMapper`，并注入上述创建好的`sqlSession`对象

## 7. 修改测试类 ##

> 此时，无需像先前一样创建sqlSessionFactory和sqlSession，我们只需获得创建好的`实体类对象`UserMapper，然后调用该对象的方法即可

public class Test { 
        @org.junit.Test
        public void test() throws IOException { 
            ApplicationContext context = new ClassPathXmlApplicationContext("spring-dao.xml");
            UserMapperImpl userMapper = (UserMapperImpl) context.getBean("userMapper");
            List<User> users = userMapper.getUser();
            for (User user : users) { 
                System.out.println(user);
            }
        }
    }

## 8. 运行测试 ##

![image-20200811194703348][]

**运行成功！！！**

# 4、spring整合：方式二 #

**通过SqlSessionDaoSupport获得Sqlsession**

--------------------

> 接下来将在上述实验环境下进行修改

## 1. 新建接口实现类 ##

新建一个接口实现类，继承`SqlSessionDaoSupport`类，直接可以获得`SqlSession`对象  
![image-20200811205114097][]

public class UserMapperImpl2 extends SqlSessionDaoSupport implements UserMapper { 
        public List<User> getUser() { 
            SqlSession sqlSession = getSqlSession();
            UserMapper mapper = sqlSession.getMapper(UserMapper.class);
            return mapper.getUser();
        }
    }

## 2. 创建接口实现类对象 ##

> 通过Spring来创建

在`spring配置文件中`创建上述实体类对象`userMapper2`，并设置`sqlSessionFactory`属性为上述创建好的sqlSessionFactory

## 3. 修改测试类 ##

> 同样，无需像先前一样创建sqlSessionFactory和sqlSession，我们只需获得创建好的`实体类对象`UserMapper2，然后调用该对象的方法即可

public class Test { 
        @org.junit.Test
        public void test() throws IOException { 
            ApplicationContext context = new ClassPathXmlApplicationContext("spring-dao.xml");
            UserMapperImpl2 userMapper = (UserMapperImpl2) context.getBean("userMapper2");
            List<User> users = userMapper.getUser();
            for (User user : users) { 
                System.out.println(user);
            }
        }
    }

## 4. 测试运行 ##

![image-20200811210202877][]

**成功运行！！**

--------------------

THE END…

[image-20200811201331833]: https://gitee.com/zhong_siru/images/raw/master//img/image-20200811201331833.png
[MyBatis]: https://blog.csdn.net/qq_45173404/article/details/107525276
[image-20200811181559385]: https://gitee.com/zhong_siru/images/raw/master//img/image-20200811181559385.png
[image-20200811181900880]: https://gitee.com/zhong_siru/images/raw/master//img/image-20200811181900880.png
[image-20200811181927962]: https://gitee.com/zhong_siru/images/raw/master//img/image-20200811181927962.png
[image-20200811182020272]: https://gitee.com/zhong_siru/images/raw/master//img/image-20200811182020272.png
[image-20200811182204453]: https://gitee.com/zhong_siru/images/raw/master//img/image-20200811182204453.png
[image-20200811182242082]: https://gitee.com/zhong_siru/images/raw/master//img/image-20200811182242082.png
[image-20200811194703348]: https://gitee.com/zhong_siru/images/raw/master//img/image-20200811194703348.png
[image-20200811183008850]: https://gitee.com/zhong_siru/images/raw/master//img/image-20200811183008850.png
[image-20200811184444369]: /images/20221124/b1833ca6e6c441528d8f1141d9c93b02.png
[image-20200811185806672]: https://gitee.com/zhong_siru/images/raw/master//img/image-20200811185806672.png
[image-20200811185526572]: https://gitee.com/zhong_siru/images/raw/master//img/image-20200811185526572.png
[image-20200811191543680]: https://gitee.com/zhong_siru/images/raw/master//img/image-20200811191543680.png
[image-20200811205114097]: https://gitee.com/zhong_siru/images/raw/master//img/image-20200811205114097.png
[image-20200811210202877]: https://gitee.com/zhong_siru/images/raw/master//img/image-20200811210202877.png