spring整合mybatis

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1.导入依赖和配置

注意：每个依赖的版本要合适

pom.xml

<?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">
    <parent>
        <artifactId>spring</artifactId>
        <groupId>cn.edu.hbue.wmp</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>spring-10-mybatis</artifactId>


    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
        <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.18</version>
        </dependency>


        <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.3</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.2.7.RELEASE</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.2.7.RELEASE</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.aspectj/aspectjweaver -->
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.9.5</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis-spring -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>2.0.3</version>
        </dependency>

    </dependencies>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <!--在build中配置resources，来防止我们资源导出失败的问题-->
    <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>

</project>

2.创建实体类

3.写UserMapper接口

4.写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="com.wang.mapper.UserMapper">
    
    <select id="getUsers" resultType="User">
        select * from user
    </select>

</mapper>

5.写UserMapperImpl

public class UserMpperImpl implements UserMapper {

    private SqlSessionTemplate sqlSession;

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

    public List<User> getUsers() {
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        return mapper.getUsers();
    }
}

6.写mybatisConfig.xml文件

注意：spring中也可以完全配置，不过最好是在mybatisConfig.xml配置设置和别名

<?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">


<!--此处只配置 设置和别名-->
<configuration> 
    <typeAliases>
        <typeAlias type="com.wang.entity.User" alias="User"/>
    </typeAliases>
</configuration>

7.spring-dao.xml

spring-dao.xml中，我们要配置数据库连接池，和sqlSessionFactory对象，以及UserMapper对象。

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

    <!--  DataSource :使用spring数据源替换mybatis配置
     使用spring提供的JDBC :org.springframework.jdbc.datasource.DriverManagerDataSource -->
    <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?useUnicode=true&amp;characterEncoding=utf8&amp;serverTimezone=UTC"/>
        <property name="username" value="root"/>
        <property name="password" value="18170021"/>
    </bean>

    <!--SqlSessionFactory -->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <!--  绑定mybatis配置文件      -->
        <property name="configLocation" value="classpath:mybatisConfig.xml"/>
        <property name="mapperLocations" value="classpath:com/wang/mapper/UserMapper.xml"/>
    </bean>

    <bean name="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
        <!--    只能构造方法注入，没有set方法   -->
        <constructor-arg index="0" ref="sqlSessionFactory"/>
    </bean>


</beans>

8.applicationContext.xml

applicationContext.xml和spring-dao.xml分工明确

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


    <!--  不负责mybatis  -->
    <import resource="spring-dao.xml"/>

    <bean id="userMapper" class="com.wang.mapper.UserMpperImpl">
        <property name="sqlSession" ref="sqlSession"/>
    </bean>


</beans>

9.测试

	@Test
    public void getUsers(){

        ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
        UserMapper userMapper = context.getBean("userMapper", UserMapper.class);
        List<User> users = userMapper.getUsers();
        for (User user : users) {
            System.out.println(user);
        }

    }

10.结果

方式二：SqlSessionDaoSupport

把上面的 第 5步 UserMapperImpl 改为如下代码

public class UserMapperImpl extends SqlSessionDaoSupport implements UserMapper {

    public List<User> getUsers() {

        return getSqlSession().getMapper(UserMapper.class).getUsers();
    }
}

然后在applicationContext.xml注入userMapper

<bean id="userMapper" class="com.wang.mapper.UserMapperImpl2">
    <property name="sqlSessionFactory" ref="sqlSessionFactory"/>
</bean>