[Java知识库]【Spring四】Spring整合Mybatis声明式事物

12.整合Mybatis

步骤

1.导入jar包

• Junit
• mybatis
• mysql
• spring
• aop
• mybatis-spring

<dependencies>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.13.2</version>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.47</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jdbc</artifactId>
        <version>5.3.16</version>
    </dependency>
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.5.2</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>5.3.16</version>
    </dependency>
    <dependency>
        <groupId>org.aspectj</groupId>
        <artifactId>aspectjweaver</artifactId>
        <version>1.9.4</version>
    </dependency>
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis-spring</artifactId>
        <version>2.0.2</version>
    </dependency>
            <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.10</version>
    </dependency>
</dependencies>
    <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>

12.1.Mybatis回忆

mybatis

• 编写实体类
• 核心配置文件
• 编写接口
• 编写Mapper.xml
• 测试

12.2.Mybatis-spring

• 1.实体类
• 2.mapper接口
• 3.mapper.xml
• 4.mybatis配置文件
  • 加设置
  • 加别名
• 5.spring整合mybatis配置文件:spring-dao.xml
  • 编写数据配置源
  • sqlSessionFactory
  • SqlSessionTemplate
• 6.mapper实现类
  • 注入SqlSessionTemplate
• 7.Spring配置文件:applicationContext.xml
  • 注册mapper
• 8.测试

12.2.1整合步骤

1.实体类

package com.ccc.pojo;
import lombok.Data;
@Data
public class User {
    private int id;
    private String name;
    private String pwd;
}

2.Mapper

package com.ccc.mapper;
import com.ccc.pojo.User;
import java.util.List;
public interface UserMapper {
    public List<User> query();
}

3.Mapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.ccc.mapper.UserMapper">
    <select id="query" resultType="user" >
        select * from mybatis.user
    </select>
</mapper>

4.Mybatis-config.xml

<?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="com.ccc.pojo"/>
    </typeAliases>
    <!--设置-->
</configuration>

5.spring整合mybatis–spring-dao.xml

<?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"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd ">
    <!--DataSource: 使用Spring的数据源替换Mybatis的配置 c3p0 dbcp druid
    我们这里使用Spring提供的JDBC
    -->
    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://192.168.0.201/mybatis?useSSL=false&amp;useUnicode=true&amp;characterEncoding=utf8"/>
        <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配置文件-->
        <property name="configLocation" value="classpath:mybatis-config.xml"/>
        <property name="mapperLocations" value="classpath:com/ccc/mapper/*.xml"/>
    </bean>
    <!--SqlSessionTemplate: 就是我们使用的sqlSession-->
    <bean id="sqlSessionTemplate" class="org.mybatis.spring.SqlSessionTemplate">
        <!--只能使用构造器注入sqlSessionFactory, 源码没有set方法-->
        <constructor-arg index="0" ref="sqlSessionFactory"/>
<!--        <constructor-arg name="sqlSessionFactory" ref="sqlSessionFactory"/>-->
    </bean>
</beans>

6.Mapper实现类

package com.ccc.mapper;
import com.ccc.pojo.User;
import org.mybatis.spring.SqlSessionTemplate;
import java.util.List;
public class UserMapperImpl implements UserMapper{
    //我们的所有操作, 原来都是用sqlSession来执行, 现在使用SqlSessionTemplate
    private SqlSessionTemplate sqlSessionTemplate;
    public void setSqlSessionTemplate(SqlSessionTemplate sqlSessionTemplate){
        this.sqlSessionTemplate = sqlSessionTemplate; //注入
    }
    @Override
    public List<User> query() {
        UserMapper mapper = sqlSessionTemplate.getMapper(UserMapper.class);
        return mapper.query();
    }
}

7.Spring配置文件:applicationContext.xml

<?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"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd ">
    <!--导入-->
    <import resource="spring-dao.xml"/>
    <bean id="userMapper" class="com.ccc.mapper.UserMapperImpl">
        <property name="sqlSessionTemplate" ref="sqlSessionTemplate"/>
    </bean>
</beans>

8.测试

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class Test {
    @org.junit.Test
    public void test1(){
        ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
        UserMapper userMapper = context.getBean("userMapper", UserMapperImpl.class);
        for (User user : userMapper.query()) {
            System.out.println(user);
        }
    }
}
//User(id=1, name=张三1, pwd=222)
//User(id=2, name=李四, pwd=344)
//User(id=3, name=张三3, pwd=123456)

12.2.2生成sqlSessionTemplate方式二

SqlSessionDaoSupport 是一个抽象的支持类，用来为你提供 SqlSession。调用 getSqlSession() 方法你会得到一个 SqlSessionTemplate，之后可以用于执行 SQL 方法

1,UserMapperImpl2

import org.apache.ibatis.session.SqlSession;
import org.mybatis.spring.support.SqlSessionDaoSupport;

import java.util.List;
//继承SqlSessionDaoSupport
public class UserMapperImpl2 extends SqlSessionDaoSupport implements UserMapper{
    @Override
    public List<User> query() {
        SqlSession sqlSession = getSqlSession();//继承后可以直接获得sqlSession
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        return mapper.query();
    }
}

2,xml中注册UserMapperImpl2

<?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"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd ">
    <!--导入-->
    <import resource="spring-dao.xml"/>
    <bean id="userMapper" class="com.ccc.mapper.UserMapperImpl">
        <property name="sqlSessionTemplate" ref="sqlSessionTemplate"/>
    </bean>
    <!--方式二: 继承SqlSessionDaoSupport 需要注入sqlSessionFactory-->
    <bean id="userMapper2" class="com.ccc.mapper.UserMapperImpl2">
        <property name="sqlSessionFactory" ref="sqlSessionFactory"/>
    </bean>
</beans>

3,测试

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class Test {
    @org.junit.Test
    public void test1(){
        ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
        UserMapper userMapper = context.getBean("userMapper2", UserMapperImpl2.class);
        for (User user : userMapper.query()) {
            System.out.println(user);
        }
    }
}
/*
User(id=1, name=张三1, pwd=222)
User(id=2, name=李四, pwd=344)
User(id=3, name=张三3, pwd=123456)
*/

13.声明式事物

13.1 回顾事物

• 把一组业务当成一个业务来做
• 要么都成功, 要么都失败
• 确保完整性和一致性

事物ACID原则

• 原子性 : 要么都成功, 要么都失败
• 一致性 : 事物前后的数据完整性要保持一致
• 隔离性 : 多个事务之间要相互隔离, 不能干扰其他事务的操作
• 持久性 : 事务一旦提交不可逆, 被持久化到数据库中

13.2 Spring中的事物管理

• 声明式事务: AOP
• 编程式事务: 需要在代码中进行事务的管理

开始步骤:

1. 开启 Spring 的事务处理功能
2. 结合AOP实现事务的接入
3. 配置事务切入

<!--1开启 Spring 的事务处理功能-->
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    <constructor-arg ref="dataSource" />
</bean>
<!--2结合AOP实现事务的接入-->
<!--配置事务通知-->
<tx:advice id="txAdvice" transaction-manager="transactionManager">
    <!--给哪些方法配置事务-->
    <!--事务传播新特性 propagation="REQUIRED"(默认) -->
    <tx:attributes>
        <tx:method name="add" propagation="REQUIRED"/>
        <tx:method name="update" propagation="REQUIRED"/>
        <tx:method name="delete" propagation="REQUIRED"/>
        <tx:method name="query" read-only="true"/>
        <tx:method name="*" propagation="REQUIRED"/>
    </tx:attributes>
</tx:advice>
<!--3配置事务切入-->
<aop:config >
    <!--配置切入点-->
    <aop:pointcut id="txPoint" expression="execution(* com.ccc.mapper.*.*(..))"/>
    <aop:pointcut id="txPoint2" expression="execution(* *(..))"/>
    <aop:advisor advice-ref="txAdvice" pointcut-ref="txPoint"/>
</aop:config>