Spring5（4）-Spring集成MyBatis

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目录

1.Spring集成MyBatis步骤

Step1：修改目录

Step2：生成可视数据库​

Step3：修改pom文件，添加相关依赖

Step4：创建MyBatis核心配置文件

Step5：创建jdbc.properties文件

Step6：创建Spring核心配置文件

Step7

Step8：测试

2.Spring接管MyBatis的众多功能

3.容易报错的位置

---

将MyBatis与Spring进行整合，主要解决的问题就是将SqlSessionFactory对象交由Spring来管理，所以该整合只需将SqlSessionFactory的对象生成器SqlSessionFactoryBean注册在Spring容器中，再让其注入给mapper的实现类即可完成整合

实现Spring与MyBatis的整合，常用的方式是扫描Mapper动态代理。Spring像插线板一样，mybatis框架是插头，可以容易的组合到一起。插线板spring插上mybatis，两个框架就是整体。

1.Spring集成MyBatis步骤

Step1：修改目录

​编辑

Step2：生成可视数据库​编辑

 Step3：修改pom文件，添加相关依赖

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.example</groupId>
    <artifactId>pro1</artifactId>
    <version>1.0-SNAPSHOT</version>
    <dependencies>
<!--        单元测试-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13.2</version>
            <scope>test</scope>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.3.19</version>
        </dependency>

        <!--        spring-context  核心ioc-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.3.19</version>
        </dependency>
<!--        spring-aspects-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aspects</artifactId>
            <version>5.3.19</version>
        </dependency>
<!--        aop-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>5.3.19</version>
        </dependency>
<!--        spring事务用到的-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>5.3.19</version>
        </dependency>
<!--        mybatis依赖-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.7</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis-spring -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>1.3.1</version>
        </dependency>

        <!--        mysql驱动-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.27</version>
        </dependency>
<!--        阿里公司数据库连接池-->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.12</version>
        </dependency>
    </dependencies>

    <build>
        <resources>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.xml</include>
                    <include>**/*.properties</include>
                </includes>
            </resource>
            <resource>
                <directory>src/main/resources</directory>
                <includes>
                    <include>**/*.xml</include>
                    <include>**/*.properties</include>
                </includes>
            </resource>
        </resources>
    </build>
</project>

Step4：创建MyBatis核心配置文件

<?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>

</configuration>

Step5：创建jdbc.properties文件

jdbc.driverClassName=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/spring
jdbc.username=root
jdbc.password=niit

Step6：创建Spring核心配置文件

也可以将Spring核心配置文件拆分成

applicationContext_mapper和applicationContext_service

<?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:p="http://www.springframework.org/schema/p"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
                           http://www.springframework.org/schema/beans/spring-beans.xsd
                           http://www.springframework.org/schema/context
                           http://www.springframework.org/schema/context/spring-context-4.2.xsd">

<!--    读取属性文件jdbc.properties    接管properties标签-->
    <context:property-placeholder location="jdbc.properties"/>
<!--    创建数据源                     接管environments标签-->
    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
        <property name="driverClassName" value="${jdbc.driverClassName}"></property>
        <property name="url" value="${jdbc.url}"></property>
        <property name="username" value="${jdbc.username}"></property>
        <property name="password" value="${jdbc.password}"></property>
    </bean>
<!--    配置SqlSessionFactoryBean类   -->
    <bean class="org.mybatis.spring.SqlSessionFactoryBean">
<!--        配置数据源-->
        <property name="dataSource" ref="dataSource"></property>
<!--        配置MyBatis的核心配置文件-->
        <property name="configLocation" value="mybatis-config.xml"></property>
<!--        注册实体类别名-->
        <property name="typeAliasesPackage" value="pojo"></property>
<!--        <property name="mapperLocations" value="mapper/UsersMapper.xml"></property>-->
    </bean>

<!--    注册mapper.xml文件           接管掉mybatis-config中的mapper标签
        这个标签已经把mapper层中的对象创建好了，具体创建的什么对象？是在mybatis中的代理对象SqlSession
        将代理对象创建的mapper对象用具体的mapper接口来接收
-->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="mapper"></property>
    </bean>
</beans>

<?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"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/context
            http://www.springframework.org/schema/context/spring-context.xsd
            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">
    <!--导入applicationContext_mapper.xml-->
    <import resource="applicationContext_mapper.xml"></import>
    <!--基于注解开发   添加包扫描-->
    <context:component-scan base-package="service.impl"/>
<!--    事务处理-->
</beans>

Step7

添加pojo包中的实体类

​编辑

public class Users {
    private Integer userId;

    private String uName;

    private String uPass;

    public Users() {
    }

    public Users(Integer userId, String uName, String uPass) {
        this.userId = userId;
        this.uName = uName;
        this.uPass = uPass;
    }

    public Integer getUserId() {
        return userId;
    }

    public void setUserId(Integer userId) {
        this.userId = userId;
    }

    public String getuName() {
        return uName;
    }

    public void setuName(String uName) {
        this.uName = uName;
    }

    public String getuPass() {
        return uPass;
    }

    public void setuPass(String uPass) {
        this.uPass = uPass;
    }

    @Override
    public String toString() {
        return "Users{" +
                "userId=" + userId +
                ", uName='" + uName + ''' +
                ", uPass='" + uPass + ''' +
                '}';
    }
}

添加mapper包中的接口和配置文件

​编辑

public interface UsersMapper {
    int insert(Users users);
}

<?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="mapper.UsersMapper">
<!--    int insert(Users users);-->
<!--    注册了别名，凡是需要用到pojo.的地方 都可以省略pojo.-->
    <insert id="insert" parameterType="users">
        insert into users values (#{userId},#{uName},#{uPass})
    </insert>
</mapper>

添加service包下的接口

​编辑

public interface UsersService {
    //增加用户
    int insert(Users users);
}

添加impl包下的业务实现类

​编辑

@Service //交给Spring去创建对象
public class UsersServiceImpl implements UsersService {
    @Autowired //自动注入代理对象sqlSession获取的mapper接口对象
    UsersMapper usersMapper;
    @Override
    public int insert(Users users) {
        return usersMapper.insert(users);
    }
}

Step8：测试

public class Test {
    @org.junit.Test
    public void test(){
        ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext_service.xml");
        UsersService userService = (UsersService) ac.getBean("usersServiceImpl");
        int insert = userService.insert(new Users(1, "zz", "123"));
        System.out.println(insert);
    }
}

2.Spring接管MyBatis的众多功能

 Spring接管mybatis的一些功能，所以mybatis核心配置文件中的一些配置可以删去，但仍然要保留mybatis核心配置文件，因为mybatis中的一些功能是spring接管不了的，如分页插件，缓存处理等。在Spring集成MyBatis后，可以将mybatis中的许多配置信息写到Spring中，下面做一些替换。

（1）properties文件

在mybatis中

<properties resource="jdbc.properties"/>

在spring中

<context:property-placeholder location="jdbc.properties"/>

（2）数据源

在mybatis中

    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="${jdbc.driver}"/>
                <property name="url" value="${jdbc.url}"/>
                <property name="username" value="${jdbc.username}"/>
                <property name="password" value="${jdbc.password}"/>
            </dataSource>
        </environment>
    </environments>

在spring中

    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
        <property name="driverClassName" value="${jdbc.driverClassName}"></property>
        <property name="url" value="${jdbc.url}"></property>
        <property name="username" value="${jdbc.username}"></property>
        <property name="password" value="${jdbc.password}"></property>
    </bean>

（3）扫描mapper

在mybatis中

    <mappers>
        <package name="mapper"/>
    </mappers>

在spring中

    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="mapper"></property>
    </bean>

3.容易报错的位置

 第一次整合时出现了好多错误，注意这些点。

1.jdbc.properties中的数据库名称

2.pom.xml中的jar包配置

3.spring核心文件的头信息

<?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"
       xmlns:p="http://www.springframework.org/schema/p"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
                           http://www.springframework.org/schema/beans/spring-beans.xsd
                           http://www.springframework.org/schema/context
                           http://www.springframework.org/schema/context/spring-context-4.2.xsd
                           http://www.springframework.org/schema/aop
                           http://www.springframework.org/schema/aop/spring-aop.xsd">

</beans>

事务

88-101

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