spring——整合Mybatis
阅读原文时间:2023年07月09日阅读:3

步骤:

  1. 导入相关jar包

    • junit
    • mybatis
    • mysql数据库
    • spring-webmvc
    • aop织入
    • mybatis-spring
    • spring-jdbc(spring的事务管理器,也可以用druid等的代替)
  2. 编写配置文件

  3. 测试

1.1 回忆mybatis
  1. 编写实体类
  2. 编写核心配置文件
  3. 编写接口
  4. 编写Mapper.xml
  5. 测试
1.2 整合方式一

注意版本限制:

  1. dataSource(这里配置使用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.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://localhost:3306/dailyClick-test?useSSL=false&amp;useUnicode=true&amp;characterEncoding=utf-8"/>
        <property name="username" value="1111"/>
        <property name="password" value="1111"/>
    </bean>

    注:Mybatis有默认的数据源(连接池),但是是可以替换的

  2. sqlSessionFactory配置

    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <!--        绑定配置文件地址和mapper地址-->
        <property name="configLocation" value="classpath:mybatis-config.xml"/>
        <property name="mapperLocations" value="classpath:com/guan/dao/*.xml"/>
    </bean>

    注意:

    • 需要配置数据源
    • 需要绑定配置文件地址和mapper地址,注意这里的路径使用classpath路径
    • 由于mapper等信息被转移到<bean>中,不能重复配置(如:<mapper>),否则会报错;mybatis-config.xml配置文件通常留<typeAlias><settings>
  3. 与在原来的mybatis不同,整合后需要有一个接口的实现类,且接口的方法需要通过sqlSessionTemplate实现(有利于bean的注册和管理,这个sqlSessioinTemplate是线程安全的)

    sqlSessionTemplate配置

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

    注:由于sqlSessionTemplate没有set方法,只有构造函数,所以通过<constructor>标签注入

  4. 实现类:与mybatis元素代码不同,接口类需要实现且接口的方法通过sqlSessionTemplate实现

    public class UserMapperImpl implements UserMapper {
        SqlSessionTemplate sqlSession;
    public void setSqlSession(SqlSessionTemplate sqlSession) {
        this.sqlSession = sqlSession;
    }
    
    public List&lt;UserBean&gt; getUserList() {
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        return mapper.getUserList();
    }
    } <bean id="userMapper" class="com.guan.dao.UserMapperImpl"> <property name="sqlSession" ref="sqlSession"/> </bean>
  5. 测试

    public class MyTest {
        public static void main(String[] args) throws IOException {
            ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
            UserMapperImpl userMapperImpl = context.getBean("userMapper", UserMapperImpl.class);
            List<UserBean> userList = userMapperImpl.getUserList();
            for (UserBean userBean : userList) {
                System.out.println(userBean);
            }
        }
    }

    注:

    (1).mybatis的配置文件(指的是和spring注册的那一部分),最好通过import引入ApplicationiContext中,这样spring配置文件的结构可以区分开

    (2).xxxTemplate是spring特有的模板类

1.3 整合方式二

注:SqlSessionDaoSupport:抽象类,可以通过SqlSessionFactory获得一个SqlSessionTemplate.所以该方法相对于第一种方法增加了一个抽象类,减少了一个配置SqlSessionTemplate的步骤

  1. 环境搭建:

    接口:

    public interface UserMapper1 {
        List<UserBean> getUserList();
    }

    xml实现

    <?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.guan.dao.UserMapper1">
        <select id="getUserList" resultType="userBean">
            SELECT  * FROM  user;
        </select>
    </mapper>

    实体类:

    public class UserMapper1Impl extends SqlSessionDaoSupport implements UserMapper1{
        public List<UserBean> getUserList() {
            return getSqlSession().getMapper(UserMapper1.class).getUserList();
        }
    }
  2. xml配置(在上文的前文的基础上配置)

    <bean id="userMapper1" class="com.guan.dao.UserMapper1Impl">
        <property name="sqlSessionFactory" ref="sqlSessionFactory"/>
    </bean>
  3. 测试:

        public static void main(String[] args) throws IOException {
            ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
            UserMapper1Impl userMapperImpl = context.getBean("userMapper1", UserMapper1Impl.class);
            List<UserBean> userList = userMapperImpl.getUserList();
            for (UserBean userBean : userList) {
                System.out.println(userBean);
            }
        }
  4. 编程式事务:将事务管理代码嵌到业务方法中控制事务的提交和回滚

    缺点:使业务逻辑中包含额外的事务管理代码

  5. 声明式事物:使用AOP

    (1).搭建环境:

    接口

    public interface UserMapper1 {
        List<UserBean> getUserList();
        void insert(UserBean user);
        void delete(String UId);
    }

    mapper:

    <insert id="insert" parameterType="userBean">
        INSERT  INTO user(UId,UName,USet,UAuth,UPassword,UState) VALUES(#{UId},#{UName},#{USet},#{UAuth},#{UPassword},#{UState});
    </insert>
    
    <delete id="delete" parameterType="string">
        DELETEs FROM user WHERE UId = #{UId};
    </delete>

    注:可以看到我这里的"DELETEs"是错误的写法

    编写实体类:

    public class UserMapper1Impl extends SqlSessionDaoSupport implements UserMapper1{
        public List<UserBean> getUserList() {
            insert(new UserBean("6666666666","淀真嗣",1,0,"123456",1));
            delete("3180421016");
            return getSqlSession().getMapper(UserMapper1.class).getUserList();
        }
    public void insert(UserBean user) {
        getSqlSession().getMapper(UserMapper1.class).insert(user);
    }
    
    public void delete(String UId) {
        getSqlSession().getMapper(UserMapper1.class).delete(UId);
    }
    }

    注:getUserList中添加了insert和delete方法,且delete方法是错误的.如果没有事务,则插入可以完成;如果有事务,则插入无法完成

    (2).导入事务相关的xml头文件约束,创建DataSourceTransaction对象以开启事务,配置事务通知,结合AOP实现事务的织入

    <?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:tx="http://www.springframework.org/schema/tx"
           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
            http://www.springframework.org/schema/tx
            https://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/aop https://www.springframework.org/schema/aop/spring-aop.xsd">
    &lt;bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"&gt;
        &lt;property name="driverClassName" value="com.mysql.jdbc.Driver"/&gt;
        &lt;property name="url" value="jdbc:mysql://47.100.90.132:3306/dailyClick-test?useSSL=false&amp;amp;useUnicode=true&amp;amp;characterEncoding=utf-8"/&gt;
        &lt;property name="username" value="root"/&gt;
        &lt;property name="password" value="aguan123"/&gt;
    &lt;/bean&gt;
    
    &lt;bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"&gt;
        &lt;property name="dataSource" ref="dataSource" /&gt;
    <!-- bind mybatis-config.xml and userMapper.xml--> <property name="configLocation" value="classpath:mybatis-config.xml"/> <property name="mapperLocations" value="classpath:com/guan/dao/*.xml"/> </bean>
    &lt;bean id="userMapper1" class="com.guan.dao.UserMapper1Impl"&gt;
        &lt;property name="sqlSessionFactory" ref="sqlSessionFactory"/&gt;
    &lt;/bean&gt;
    <!-- 配置声明式事务--> <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="dataSource"/> </bean> <!-- 配置事务通知--> <tx:advice id="txAdvice" transaction-manager="transactionManager"> <tx:attributes> <tx:method name="getUserList" propagation="REQUIRED"/> </tx:attributes> </tx:advice> <!-- 结合AOP织入事务--> <aop:config> <aop:pointcut id="point" expression="execution(* com.guan.dao.*.*(..))"/> <!-- <aop:advisor advice-ref="txAdvice" pointcut-ref="point"/>--> </aop:config> </beans>

    注:<tx:method name="getUserList" propagation="REQUIRED"/>的propagation属性表示对这些方法怎样使用事务,如:REQUIRED表示支持当前事务,如果当前没有事务,就新建一个事务 (Default)

    (3).测试

    public class MyTest {
    public static void main(String[] args) throws IOException {
        ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
        UserMapper1 userMapperImpl = context.getBean("userMapper1", UserMapper1.class);
        List&lt;UserBean&gt; userList = userMapperImpl.getUserList();
        for (UserBean userBean : userList) {
            System.out.println(userBean);
        }
    }
    }

    注意:由于使用了AOP,这里UserMapper1 userMapperImpl = context.getBean("userMapper1", UserMapper1.class)的返回类型必须为interface类型,而不是实体类型