Spring学习笔记-Spring整合Mybatis

2024-01-02 19:21:28

创建项目&搭建环境

导入依赖（jar包）

  • junit
  • mybatis
  • mysql数据库
  • spring相关
  • aop织入
  • mybatis-spring【叮！获得新知识点】
    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.22</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.7</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.3.9</version>
        </dependency>
        <!--Spring操作数据库-->
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.3.9</version>
        </dependency>
        <!--AOP织入-->
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjrt</artifactId>
            <version>1.8.14</version>
        </dependency>
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.8.14</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>
    </dependencies>

编写实体类（数据库数据略）

package cn.iris.pojo;

/**
 * @author Iris 2021/8/13
 */
public class User {
    private int id;
    private String name;
    private String 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;
    }

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

编写interface UserMapper（略）&UserMapper.xml

<?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="cn.iris.mapper.UserMapper">

    <select id="selectUser" resultType="User">
        SELECT * FROM user;
    </select>
</mapper>

编写配置文件【mybatis-config】

<?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>

    <properties resource="db.properties"/>

    <typeAliases>
        <package name="cn.iris.pojo"/>
    </typeAliases>

    <environments default="mybatis">
        <environment id="mybatis">
            <transactionManager type="JDBC"/><!-- 单独使用时配置成MANAGED没有事务 -->
            <dataSource type="POOLED">
                <property name="driver" value="${driver}"/>
                <property name="url" value="${url}"/>
                <property name="username" value="${username}"/>
                <property name="password" value="${password}"/>
            </dataSource>
        </environment>
    </environments>

    <mappers>
        <mapper class="cn.iris.mapper.UserMapper"/>
    </mappers>

</configuration>

【tip】解决资源扫描问题

在pom.xml文件中加入以下语句

    <build>
        <resources>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>false</filtering>
            </resource>
            <!-- 由于修改了默认的resource目录，导致src/main/resources的所有文件都不能被扫描，因此还要配多一个 -->
            <resource>
                <directory>src/main/resources</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>false</filtering>
            </resource>
        </resources>
    </build>

整合Spring方式一

由Spring接管Myabtis业务

  • 【spring-mapper.xml】：负责Mybatis的mapper注册，数据库连接以及sqlSession的创建（使用Spring的SqlSessionTemplate）
<?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">

    <bean class="cn.iris.pojo.User"/>

    <!--Datasource 使用Spring的数据源替换Mybatis的配置-->
    <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?useSSL=false&amp;allowPublicKeyRetrieval=true&amp;serverTimezone=Asia/Shanghai"/>
        <property name="username" value="root"/>
        <property name="password" value="123456"/>
    </bean>

    <!--SqlSessionFactory-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="datasource"/>
        <!--绑定mybatis-config+mapper-->
        <property name="configLocation" value="classpath:mybatis-config.xml"/>
        <property name="mapperLocations" value="cn/iris/mapper/UserMapper.xml"/>
    </bean>

    <!--SqlSessionTemplate 等同于SqlSessionFactory-->
    <bean id="sqlSessionTemplate" class="org.mybatis.spring.SqlSessionTemplate">
        <!--只能使用构造器注入sqlSessionFactory（没有Setter）-->
        <constructor-arg index="0" ref="sqlSessionFactory"/>
    </bean>

    <!---->
    <bean id="userMapper" class="cn.iris.mapper.UserMapperImpl">
        <property name="sqlSession" ref="sqlSessionTemplate"/>
    </bean>

</beans>
  • 【applicationConfig.xml】：Spring全局配置
<?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">

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

</beans>
  • 【mybatis-config.xml】：由Spring接管后，只需保留别名设置以及部分核心设置（日志、驼峰命名...）内容
<?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>

    <typeAliases>
        <package name="cn.iris.pojo"/>
    </typeAliases>

<!--    <settings>-->
<!--        <setting name="" value=""/>-->
<!--    </settings>-->

</configuration>
  • 【Class UsermapperImpl】：继承InterFace UserMapper，完成SQlSessionTemplate执行sql操作
package cn.iris.mapper;

import cn.iris.pojo.User;
import org.mybatis.spring.SqlSessionTemplate;

import java.util.List;

/**
 * @author Iris 2021/8/13
 */
public class UserMapperImpl implements UserMapper{

    // 之前：所有操作都用SQLSession执行
    // 现在：都由SqlSessionTemplate执行

    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();
    }
}

【测试】

    @Test
    public void selectUser() throws IOException {

        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("spring-mapper.xml");
        UserMapper userMapper = context.getBean("userMapper", UserMapper.class);
        List<User> users = userMapper.selectUser();

        for ( User user : users) {
            System.out.println(user);
        }
    }
}

Spring学习笔记-Spring整合Mybatis

整合Spring方式二

【SqlSessionDaoSupport(Spring5.2及以上版本支持)】

  • Class UserMapperImp2
package cn.iris.mapper;

import cn.iris.pojo.User;
import org.mybatis.spring.support.SqlSessionDaoSupport;

import java.util.List;

/**
 * @author Iris 2021/8/13
 */
public class UserMapperImpl2 extends SqlSessionDaoSupport implements UserMapper{

    @Override
    public List<User> selectUser() {
        return getSqlSession().getMapper(UserMapper.class).selectUser();
    }
}
  • 在applicationConfig.xml中注册Bean
<bean id="userMapper2" class="cn.iris.mapper.UserMapperImpl2">
    <property name="sqlSessionFactory" ref="sqlSessionFactory"/>
</bean>
  • 测试
    @Test
    public void selectUser() throws IOException {

        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("applicationConfig.xml");
        UserMapper userMapper = context.getBean("userMapper2", UserMapper.class);
        List<User> users = userMapper.selectUser();

        for ( User user : users) {
            System.out.println(user);
        }
    }
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