经典分布式事务,是相对互联网中的柔性分布式事务而言,其特性为ACID原则,包括原子性(Atomictiy)、一致性(Consistency)、隔离性(Isolation)、持久性(Durabilit):
- 原子性:事务是一个包含一系列操作的原子操作。事务的原子性确保这些操作全部完成或者全部失败。
- 一致性:一旦事务的所有操作结束,事务就被提交。然后你的数据和资源将处于遵循业务规则的一直状态。
- 隔离性:因为同时在相同数据集上可能有许多事务处理,每个事务应该与其他事务隔离,避免数据破坏。
- 持久性:一旦事务完成,他的结果应该能够承受任何系统错误(想象一下在事务提交过程中机器的电源被切断的情况)。通常,事务的结果被写入持续性存储。
XA是啥?
XA是由X/Open组织提出的分布式事务的架构(或者叫协议)。XA架构主要定义了(全局)事务管理器(Transaction Manager)和(局部)资源管理器(Resource Manager)之间的接口。XA接口是双向的系统接口,在事务管理器(Transaction Manager)以及一个或多个资源管理器(Resource Manager)之间形成通信桥梁。也就是说,在基于XA的一个事务中,我们可以针对多个资源进行事务管理,例如一个系统访问多个数据库,或即访问数据库、又访问像消息中间件这样的资源。这样我们就能够实现在多个数据库和消息中间件直接实现全部提交、或全部取消的事务。XA规范不是java的规范,而是一种通用的规范,
目前各种数据库、以及很多消息中间件都支持XA规范。
JTA是满足XA规范的、用于Java开发的规范。所以,当我们说,使用JTA实现分布式事务的时候,其实就是说,使用JTA规范,实现系统内多个数据库、消息中间件等资源的事务。
JTA(Java Transaction API),是J2EE的编程接口规范,它是XA协议的JAVA实现。它主要定义了:
- 一个事务管理器的接口javax.transaction.TransactionManager,定义了有关事务的开始、提交、撤回等>操作。
- 一个满足XA规范的资源定义接口javax.transaction.xa.XAResource,一种资源如果要支持JTA事务,就需要让它的资源实现该XAResource接口,并实现该接口定义的两阶段提交相关的接口。如果我们有一个应用,它使用JTA接口实现事务,应用在运行的时候,就需要一个实现JTA的容器,一般情况下,这是一个J2EE容器,像JBoss,Websphere等应用服务器。但是,也有一些独立的框架实现了JTA,例如 Atomikos, bitronix 都提供了jar包方式的JTA实现框架。这样我们就能够在Tomcat或者Jetty之类的服务器上运行使用JTA实现事务的应用系统。在上面的本地事务和外部事务的区别中说到,JTA事务是外部事务,可以用来实现对多个资源的事务性。它正是通过每个资源实现的XAResource来进行两阶段提交的控制。感兴趣的同学可以看看这个接口的方法,除了commit, rollback等方法以外,还有end(), forget(), isSameRM(), prepare()等等。光从这些接口就能够想象JTA在实现两阶段事务的复杂性。
本篇以Spring MVC+Maven+Atomikos+Druid+MyBatis演示分布式事务的实现。
Mave 的pom.xml
<properties>
<jdk.version>1.8</jdk.version>
<!-- 注mysql的版本和druid的版本一定要搭配,否则会有问题,目前这两个版本是搭配好的 -->
<mysql.version>8.0.11</mysql.version>
<druid.version>1.1.17</druid.version>
<spring.version>5.1.8.RELEASE</spring.version>
<cglib.version>3.2.12</cglib.version>
<atomikos.version>5.0.0</atomikos.version>
<aspectjweaver.version>1.9.4</aspectjweaver.version>
<aspectjrt.version>1.5.4</aspectjrt.version>
<jta.version>1.1</jta.version>
<mybatise.version>3.2.0</mybatise.version>
<mybatis.spring>1.2.0</mybatis.spring>
<log4j.version>1.2.17</log4j.version>
<junit.version>4.12</junit.version>
<cglib.version>3.2.4</cglib.version>
</properties>
<dependencies>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>${mybatise.version}</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>${mybatis.spring}</version>
</dependency>
<dependency>
<groupId>com.atomikos</groupId>
<artifactId>atomikos-util</artifactId>
<version>${atomikos.version}</version>
</dependency>
<dependency>
<groupId>com.atomikos</groupId>
<artifactId>transactions</artifactId>
<version>${atomikos.version}</version>
</dependency>
<dependency>
<groupId>com.atomikos</groupId>
<artifactId>transactions-jta</artifactId>
<version>${atomikos.version}</version>
</dependency>
<dependency>
<groupId>com.atomikos</groupId>
<artifactId>transactions-jdbc</artifactId>
<version>${atomikos.version}</version>
</dependency>
<dependency>
<groupId>com.atomikos</groupId>
<artifactId>transactions-api</artifactId>
<version>${atomikos.version}</version>
</dependency>
<dependency>
<groupId>javax.transaction</groupId>
<artifactId>jta</artifactId>
<version>${jta.version}</version>
</dependency>
<dependency>
<groupId>cglib</groupId>
<artifactId>cglib-nodep</artifactId>
<version>${cglib.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-orm</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context-support</artifactId>
<version>${spring.version}</version>
</dependency>
<!-- Spring Aop依赖jar -->
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>${aspectjweaver.version}</version>
</dependency>
<dependency>
<groupId>aspectj</groupId>
<artifactId>aspectjrt</artifactId>
<version>${aspectjrt.version}</version>
</dependency>
<!-- CGLIB -->
<dependency>
<groupId>cglib</groupId>
<artifactId>cglib</artifactId>
<version>${cglib.version}</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>${mysql.version}</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>${druid.version}</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>${junit.version}</version>
<scopte>test</scope>
</dependency>
</dependencies>
spring-application-context.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:p="http://www.springframework.org/schema/p"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:task="http://www.springframework.org/schema/task"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-3.1.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.1.xsd
http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.1.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.1.xsd">
<!-- 1. 数据源配置 -->
<context:property-placeholder location="classpath*:*.properties" file-encoding="utf8" />
<bean id="utf8" class="java.lang.String">
<constructor-arg value="utf-8"></constructor-arg>
</bean>
<!-- 开启异步任务(同时开启定时器注解扫描) -->
<task:annotation-driven />
<!-- 使用@AspectJ风格的切面声明 -->
<!-- <aop:aspectj-autoproxy/> -->
<!-- 使用Annotation自动注册Bean -->
<!-- 在主容器中不扫描@Controller注解,在SpringMvc中只扫描@Controller注解 -->
<context:component-scan base-package="net.xiake6"><!-- base-package 如果多个,用“,”分隔 -->
<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller" />
</context:component-scan>
<!-- 引入Mybatis配置 -->
<!-- <import resource="spring-mybatis-atomikos-druid.xml"/> -->
<import resource="spring-mybatis-atomikos-druid.xml"/>
</beans>
spring-mybatis-atomikos-druid.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:jee="http://www.springframework.org/schema/jee"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
http://www.springframework.org/schema/jee
http://www.springframework.org/schema/jee/spring-jee-3.0.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd"
default-lazy-init="true">
<context:annotation-config />
<!-- 使用Druid使为XA数据源 -->
<bean id="abstractXADataSource" class="com.atomikos.jdbc.AtomikosDataSourceBean" init-method="init" destroy-method="close" abstract="true">
<property name="xaDataSourceClassName" value="com.alibaba.druid.pool.xa.DruidXADataSource"/>
<property name="xaProperties">
<props>
<prop key="driverClassName">${jdbc.driverClassName}</prop>
<!-- 配置初始化大小、最小、最大 -->
<prop key="initialSize">10</prop>
<prop key="minIdle">3</prop>
<prop key="maxActive">100</prop>
<!-- 配置获取连接等待超时的时间 -->
<prop key="maxWait">60000</prop>
<!-- 配置间隔多久才进行一次检测,检测需要关闭的空闲连接,单位是毫秒 -->
<prop key="timeBetweenEvictionRunsMillis">60000</prop>
<!-- 配置一个连接在池中最小生存的时间,单位是毫秒 -->
<prop key="minEvictableIdleTimeMillis">300000</prop>
<prop key="validationQuery">SELECT 'x'</prop>
<prop key="testWhileIdle">true</prop>
<prop key="testOnBorrow">false</prop>
<prop key="testOnReturn">false</prop>
<!-- 配置监控统计拦截的filters -->
<prop key="filters">stat</prop>
</props>
</property>
</bean>
<!-- 配置数据源一 -->
<bean id="dataSourceOne" parent="abstractXADataSource">
<property name="uniqueResourceName">
<value>dataSourceOne</value>
</property>
<property name="xaProperties">
<props>
<prop key="url">${jdbc.url}</prop>
<prop key="username">${jdbc.username}</prop>
<prop key="password">${jdbc.password}</prop>
</props>
</property>
</bean>
<!--配置数据源二-->
<bean id="dataSourceTwo" parent="abstractXADataSource">
<property name="uniqueResourceName">
<value>dataSourceTwo</value>
</property>
<property name="xaProperties">
<props>
<prop key="url">${jdbc.two.url}</prop>
<prop key="username">${jdbc.two.username}</prop>
<prop key="password">${jdbc.two.password}</prop>
</props>
</property>
</bean>
<!--mybatis的相关配置-->
<bean id="sqlSessionFactoryOne" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSourceOne"/>
<property name="mapperLocations" value="classpath*:mapping/ds1/*.xml"/>
</bean>
<bean id="sqlSessionFactoryTwo" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSourceTwo"/>
<property name="mapperLocations" value="classpath*:mapping/ds2/*.xml"/>
</bean>
<!--配置mybatis映射文件自动扫描-->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="net.xiake6.dao.ds1"/>
<property name="sqlSessionFactoryBeanName" value="sqlSessionFactoryOne"/>
</bean>
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="net.xiake6.dao.ds2"/>
<property name="sqlSessionFactoryBeanName" value="sqlSessionFactoryTwo"/>
</bean>
<!--配置分布式事务-->
<bean id="atomikosTransactionManager" class="com.atomikos.icatch.jta.UserTransactionManager" init-method="init" destroy-method="close">
<property name="forceShutdown" value="false"/>
</bean>
<bean id="atomikosUserTransaction" class="com.atomikos.icatch.jta.UserTransactionImp">
<property name="transactionTimeout" value="3000"/>
</bean>
<!--JTA事务管理器-->
<bean id="jtaTransactionManager" class="org.springframework.transaction.jta.JtaTransactionManager">
<property name="transactionManager">
<ref bean="atomikosTransactionManager"/>
</property>
<property name="userTransaction">
<ref bean="atomikosUserTransaction"/>
</property>
<property name="allowCustomIsolationLevels" value="true"/>
</bean>
<aop:config proxy-target-class="true">
<aop:advisor pointcut="execution(* *net.xiake6.service..*(..))" advice-ref="txAdvice" />
</aop:config>
<tx:advice id="txAdvice" transaction-manager="jtaTransactionManager">
<tx:attributes>
<tx:method name="insert*" propagation="REQUIRED" read-only="false" rollback-for="*Exception"/>
<tx:method name="add*" propagation="REQUIRED" read-only="false" rollback-for="*Exception" />
<tx:method name="save*" propagation="REQUIRED" read-only="false" rollback-for="*Exception" />
<tx:method name="delete*" propagation="REQUIRED" read-only="false" rollback-for="*Exception" />
<tx:method name="del*" propagation="REQUIRED" read-only="false" rollback-for="*Exception" />
<tx:method name="update*" propagation="REQUIRED" read-only="false" rollback-for="*Exception" />
<tx:method name="select*" propagation="REQUIRED" read-only="true" />
<tx:method name="query" propagation="REQUIRED" read-only="true" />
</tx:attributes>
</tx:advice>
<!-- 配置事务管理 -->
<tx:annotation-driven transaction-manager="jtaTransactionManager" />
</beans>
jdbc.properties
#mysql 6.*以上
jdbc.driverClassName = com.mysql.cj.jdbc.Driver
jdbc.url = jdbc:mysql://127.0.0.1:3306/test?serverTimezone=UTC&useUnicode=true&characterEncoding=UTF-8&pinGlobalTxToPhysicalConnection=true&useSSL=false
jdbc.username =root
jdbc.password =root
jdbc.two.url = jdbc:mysql://127.0.0.1:3306/test?serverTimezone=UTC&useUnicode=true&characterEncoding=UTF-8&pinGlobalTxToPhysicalConnection=true&useSSL=false
jdbc.two.username =root
jdbc.two.password =root
jta.properties
com.atomikos.icatch.service=com.atomikos.icatch.standalone.UserTransactionServiceFactory
com.atomikos.icatch.console_file_name=tm.release.out
com.atomikos.icatch.log_base_name=tm.releaselog
com.atomikos.icatch.tm_unique_name=com.atomikos.spring.jdbc.tm.release
com.atomikos.icatch.console_log_level=INFO
TestInsert.java
@ContextConfiguration(value = {"classpath:spring-application-context.xml"})
@RunWith(SpringJUnit4ClassRunner.class)
public class TestInsert {
private Logger logger = LoggerFactory.getLogger(TestInsert.class);
@Autowired
private BatchInsertService batchInsertService;
@Test
public void insert(){
long startTime = System.currentTimeMillis();
User user = new User();
user.setName("User_"+(int)(Math.random()*100));
user.setAge((int)(Math.random()*100));
CustInfo info = new CustInfo();
info.setPhone("123456789"+(int)(Math.random()*100));
batchInsertService.insert(user,info);
long endTime = System.currentTimeMillis();
logger.info("共耗时:{}毫秒",endTime -startTime);
}
}
BatchInsertService.java
@Service
public class BatchInsertService {
private Logger logger = LoggerFactory.getLogger(BatchInsertService.class);
@Autowired
private UserService userService;
@Autowired
private CustInfoService custInfoService;
@Transactional(rollbackFor= {Exception.class,RuntimeException.class})
public void insert(User user,CustInfo custInfo) {
int insertUser = userService.insert(user);
logger.info("insertUser={}",insertUser);
int insertCustInfo = custInfoService.insert(custInfo);
logger.info("insertCustInfo={}",insertCustInfo);
}
}
UserService.java
@Service
public class UserService {
@Autowired
private UserMapper userMapper;
public int insert(User record) {
int result = userMapper.insert(record);
return result;
}
}
CustInfoService.java
@Service
public class CustInfoService {
@Autowired
private CustInfoMapper custInfoMapper;
public int insert(CustInfo record) {
int result = custInfoMapper.insert(record);
long now = System.currentTimeMillis();
// 模拟一个异常
if (now % 2 == 0) {
throw new RuntimeException("CustInfoMapper throws test insert exception");
}
return result;
}
}
Mapper和Bean等就不列出来了,完成的示例工程在github: https://github.com/fenglibin/DruidWithAtomikos
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持w3xue。