最新Spring整合MyBatis詳解教程

首先新建一個(gè)空的maven項(xiàng)目

1、導(dǎo)入相關(guān)jar包

1. junit

????junit
????junit
????4.13
????test

2. mybatis

????org.mybatis
????mybatis
????3.5.5

3. mysql

????mysql
????mysql-connector-java
????8.0.21

4. spring相關(guān)

????org.springframework
????spring-webmvc
????5.2.8.RELEASE



????org.springframework
????spring-jdbc
????5.1.3.RELEASE

5. aop織入

????org.aspectj
????aspectjweaver
????1.9.4

6. mybatis-spring

????org.mybatis
????mybatis-spring
????2.0.5

7. lombok（選用）

????org.projectlombok
????lombok
????1.18.12

最后為了防止maven配置文件無法被導(dǎo)出或生效，加入以下代碼

????
????????
????????????src/main/resources
????????????
????????????????**/*.properties
????????????????**/*.xml
????????????
????????????true
????????
????????
????????????src/main/java
????????????
????????????????**/*.properties
????????????????**/*.xml
????????????
????????????true
????????
????

2、回顧：建立一個(gè)Mybatis程序

1. IDEA連接數(shù)據(jù)庫(kù)

大家連接自己的數(shù)據(jù)庫(kù)即可，這里的實(shí)驗(yàn)表格為

2. 編寫MyBatis核心配置文件

"1.0"?encoding="UTF-8"??>
????????PUBLIC?"-//mybatis.org//DTD?Config?3.0//EN"
????????"http://mybatis.org/dtd/mybatis-3-config.dtd">

????default="development">
????????"development">
????????????"JDBC"/>
????????????"POOLED">
????????????????"driver"?value="com.mysql.jdbc.Driver"/>
????????????????"url"?value="jdbc:mysql://localhost:3306/mybatis?useSSH=true&useUnicode=true&characterEncoding=UTF-8"/>
????????????????"username"?value="root"/>
????????????????"password"?value="200024"/>
????????????
????????
????

3. 創(chuàng)建數(shù)據(jù)庫(kù)表對(duì)應(yīng)實(shí)體類

package?pojo;

import?lombok.Data;

@Data
public?class?User?{
????private?int?id;
????private?String?name;
????private?String?pwd;
}

4. 編寫Mapper接口

package?mapper;

import?pojo.User;

import?java.util.List;

public?interface?UserMapper?{
????public?List?getUser();
}

5. 編寫Mapper.xml配置文件

"1.0"?encoding="UTF-8"??>
????????PUBLIC?"-//mybatis.org//DTD?Config?3.0//EN"
????????"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
"mapper.UserMapper">
????"getUser"?resultType="pojo.User">
????????select?*?from?mybatis.user
????

6. 編寫測(cè)試類

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?users?=?mapper.getUser();
????????for?(User?user?:?users)?{
????????????System.out.println(user);
????????}
????}
}

7. 給Mapper.xml添加注冊(cè)

在核心配置文件mybatis-config.xml中加入以下代碼

????class="mapper.UserMapper"/>

8. 測(cè)試運(yùn)行

3、spring整合：方式一

通過SqlSessionTemplate創(chuàng)建SqlSession

接下來將在上述實(shí)驗(yàn)環(huán)境下進(jìn)行修改

1. 引入spring配置文件

在resource目錄下新建spring-dao.xml

"1.0"?encoding="UTF-8"?>
"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">

2. 使用Spring的數(shù)據(jù)源替換MyBatis的數(shù)據(jù)源配置

在spring配置文件中加入以下代碼，配置數(shù)據(jù)源信息

"dataSource"?class="org.springframework.jdbc.datasource.DriverManagerDataSource">
????"driverClassName"?value="com.mysql.cj.jdbc.Driver"/>
????"url"
??????????????value="jdbc:mysql://localhost:3306/mybatis?useSSH=true&useUnicode=true&characterEncoding=UTF-8"/>
????"username"?value="root"/>
????"password"?value="200024"/>

此時(shí)，就可以刪除mybatis核心配置文件mybatis-config.xml中的數(shù)據(jù)源配置

3. 通過spring創(chuàng)建sqlSessionFactory

• 在 MyBatis 中，是通過 SqlSessionFactoryBuilder 來創(chuàng)建 SqlSessionFactory

• 而在 MyBatis-Spring 中，則使用 SqlSessionFactoryBean 來創(chuàng)建

在spring配置文件中加入以下代碼，創(chuàng)建sqlSessionFactory

"sqlSessionFactory"?class="org.mybatis.spring.SqlSessionFactoryBean">
????"dataSource"?ref="dataSource"/>

唯一的必要屬性：用于 JDBC 的 DataSource，注入上述創(chuàng)建好的數(shù)據(jù)源

還可以配置其他屬性，完全取代mybatis-config.xml中的配置

• configLocation：指定mybatis的xml配置文件路徑

• mapperLocations：注冊(cè)Mapper.xm映射器

"sqlSessionFactory"?class="org.mybatis.spring.SqlSessionFactoryBean">
????"dataSource"?ref="dataSource"/>
????
????"configLocation"?value="classpath:mybatis-config.xml"/>
????
????"mapperLocations"?value="classpath:mapper/*.xml"/>

這里，我們?cè)?code style="font-size: inherit;line-height: inherit;padding: 2px 4px;border-radius: 4px;margin-right: 2px;margin-left: 2px;color: rgb(233, 105, 0);background: rgb(248, 248, 248);">spring配置文件中注冊(cè)了Mapper.xml，就可以刪除mybatis-config.xml中的Mapper.xml的注冊(cè)

4. 創(chuàng)建sqlSession對(duì)象

• 在mybatis中，SqlSession 提供了在數(shù)據(jù)庫(kù)執(zhí)行 SQL 命令所需的所有方法

• 而在spring-mybatis，沒有SqlSession了，而是SqlSessionTemplate，這兩個(gè)是同一個(gè)東西

在spring配置文件中加入以下代碼，創(chuàng)建sqlSession

• 這里使用上述創(chuàng)建好的sqlSessionFactory 作為構(gòu)造方法的參數(shù)來創(chuàng)建 SqlSessionTemplate 對(duì)象。

"sqlSession"?class="org.mybatis.spring.SqlSessionTemplate">
????
????"0"?ref="sqlSessionFactory"/>

5. 新建接口實(shí)現(xiàn)類

上一步我們創(chuàng)建了sqlSession對(duì)象，此時(shí)需要?jiǎng)?chuàng)建一個(gè)類來使用sqlSession

public?class?UserMapperImpl?implements?UserMapper?{
????//原來所有操作都通過SqlSession來執(zhí)行，現(xiàn)在都是SqlSessionTemplate
????private?SqlSessionTemplate?sqlSession;

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

????public?List?getUser()?{
????????UserMapper?mapper?=?sqlSession.getMapper(UserMapper.class);
????????return?mapper.getUser();
????}
}

6. 創(chuàng)建實(shí)現(xiàn)類對(duì)象

利用spring創(chuàng)建上述接口實(shí)現(xiàn)類對(duì)象，取名為userMapper，并注入上述創(chuàng)建好的sqlSession對(duì)象

"userMapper"?class="mapper.UserMapperImpl">
????"sqlSession"?ref="sqlSession"/>

7. 修改測(cè)試類

此時(shí)，無需像先前一樣創(chuàng)建sqlSessionFactory和sqlSession，我們只需獲得創(chuàng)建好的``實(shí)體類對(duì)象```UserMapper，然后調(diào)用該對(duì)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?users?=?userMapper.getUser();
????????for?(User?user?:?users)?{
????????????System.out.println(user);
????????}
????}
}

8. 運(yùn)行測(cè)試

4、spring整合：方式二

通過SqlSessionDaoSupport獲得Sqlsession

接下來將在上述實(shí)驗(yàn)環(huán)境下進(jìn)行修改

1. 新建接口實(shí)現(xiàn)類

新建一個(gè)接口實(shí)現(xiàn)類，繼承SqlSessionDaoSupport類，直接可以獲得SqlSession對(duì)象

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

2. 創(chuàng)建接口實(shí)現(xiàn)類對(duì)象

通過Spring來創(chuàng)建

在spring配置文件中創(chuàng)建上述實(shí)體類對(duì)象userMapper2，并設(shè)置sqlSessionFactory屬性為上述創(chuàng)建好的sqlSessionFactory

"userMapper2"?class="mapper.UserMapperImpl2">
????"sqlSessionFactory"?ref="sqlSessionFactory"/>

3. 修改測(cè)試類

同樣，無需像先前一樣創(chuàng)建sqlSessionFactory和sqlSession，我們只需獲得創(chuàng)建好的實(shí)體類對(duì)象UserMapper2，然后調(diào)用該對(duì)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?users?=?userMapper.getUser();
????????for?(User?user?:?users)?{
????????????System.out.println(user);
????????}
????}
}

4. 測(cè)試運(yùn)行

成功運(yùn)行！！