个人备忘
事务(官方解释):是由一组sql语句组成的“逻辑处理单元”。
事务具有如下四个属性,通常称为事务的ACID属性 :
1. 原子性(Atomicity): 事务是一个原子操作单元,要么都执行,要么都不执行。
2. 一致性(Consistent):在事务开始和完成时,数据都必须保持一致。
3. 隔离性(Isoation): 数据库系统提供一定的隔离机制,保证事务在不受外部并发操作影响的“独立”环境执行。
4. 持久性(Durabe): 事务完成之后,它对数据的修改是永久性的。
分布式事务 : 分布式事务就是指事务的参与者,支持事务的服务器,资源服务器,以及事务管理器分别位于不同的分布式系统的不同节点之上。
本质上来说,分布式事务就是为了保证“不同数据库的数据一致性” 。
分布式事务产生场景 :
分布式事务管理器 :
XA 协议 是可以在数据库conmit 之后进行回滚的。
常见分布式事务解决方案 :
通过日志来记录操作 ,从上到下任何一步有问题,就会rollback , 如下图 :
XA优缺点:
常见数据库都对XA 协议有支持,成本低。
XA相关框架:
Atomikos 代码实现:
基于ssm
//pom.xml
<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">
<modelVersion>4.0.0modelVersion>
<groupId>com.xygroupId>
<artifactId>springmvc-mybatisartifactId>
<version>1.0-SNAPSHOTversion>
<packaging>warpackaging>
<properties>
<spring.version>4.1.1.RELEASEspring.version>
properties>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.pluginsgroupId>
<artifactId>maven-surefire-pluginartifactId>
<version>2.15version>
<configuration>
<skip>trueskip>
configuration>
plugin>
<plugin>
<groupId>org.apache.maven.pluginsgroupId>
<artifactId>maven-compiler-pluginartifactId>
<version>3.1version>
<configuration>
<source>1.7source>
<target>1.7target>
<debug>truedebug>
configuration>
plugin>
<plugin>
<groupId>org.apache.maven.pluginsgroupId>
<artifactId>maven-war-pluginartifactId>
plugin>
<plugin>
<groupId>org.mortbay.jettygroupId>
<artifactId>maven-jetty-pluginartifactId>
<version>6.1.26version>
<configuration>
<scanIntervalSeconds>10scanIntervalSeconds>
<webAppConfig>
<contextPath>/maven-appcontextPath>
webAppConfig>
configuration>
plugin>
plugins>
build>
<dependencies>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-jdbcartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-context-supportartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-contextartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>com.fasterxml.jackson.coregroupId>
<artifactId>jackson-coreartifactId>
<version>2.3.0version>
dependency>
<dependency>
<groupId>com.fasterxml.jackson.coregroupId>
<artifactId>jackson-databindartifactId>
<version>2.3.0version>
dependency>
<dependency>
<groupId>ch.qos.logbackgroupId>
<artifactId>logback-classicartifactId>
<version>1.0.11version>
dependency>
<dependency>
<groupId>ch.qos.logbackgroupId>
<artifactId>logback-coreartifactId>
<version>1.0.11version>
dependency>
<dependency>
<groupId>org.slf4jgroupId>
<artifactId>slf4j-apiartifactId>
<version>1.7.6version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-webmvcartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>javax.servletgroupId>
<artifactId>servlet-apiartifactId>
<version>2.5version>
<scope>providedscope>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-ormartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-txartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>commons-dbcpgroupId>
<artifactId>commons-dbcpartifactId>
<version>1.4version>
dependency>
<dependency>
<groupId>commons-fileuploadgroupId>
<artifactId>commons-fileuploadartifactId>
<version>1.3.1version>
dependency>
<dependency>
<groupId>com.mchangegroupId>
<artifactId>c3p0artifactId>
<version>0.9.2.1version>
dependency>
<dependency>
<groupId>javax.servletgroupId>
<artifactId>javax.servlet-apiartifactId>
<version>3.1.0version>
dependency>
<dependency>
<groupId>org.mybatisgroupId>
<artifactId>mybatisartifactId>
<version>3.2.7version>
dependency>
<dependency>
<groupId>mysqlgroupId>
<artifactId>mysql-connector-javaartifactId>
<version>5.0.8version>
dependency>
<dependency>
<groupId>org.mybatisgroupId>
<artifactId>mybatis-springartifactId>
<version>1.2.2version>
dependency>
<dependency>
<groupId>com.atomikosgroupId>
<artifactId>atomikos-utilartifactId>
<version>3.7.0version>
dependency>
<dependency>
<groupId>com.atomikosgroupId>
<artifactId>transactions-jtaartifactId>
<version>3.7.0version>
dependency>
<dependency>
<groupId>com.atomikosgroupId>
<artifactId>transactionsartifactId>
<version>3.7.0version>
dependency>
<dependency>
<groupId>com.atomikosgroupId>
<artifactId>transactions-apiartifactId>
<version>3.7.0version>
dependency>
<dependency>
<groupId>com.atomikosgroupId>
<artifactId>transactions-jdbcartifactId>
<version>3.7.0version>
dependency>
<dependency>
<groupId>org.codehaus.btmgroupId>
<artifactId>btmartifactId>
<version>2.1.4version>
dependency>
dependencies>
project>
spring-mybatis.xml
<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:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx" xmlns:jdbc="http://www.springframework.org/schema/jdbc"
xmlns:rabbit="http://www.springframework.org/schema/rabbit"
xmlns:cache="http://www.springframework.org/schema/cache" xmlns:task="http://www.springframework.org/schema/task"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc.xsd http://www.springframework.org/schema/rabbit http://www.springframework.org/schema/rabbit/spring-rabbit.xsd
http://www.springframework.org/schema/cache http://www.springframework.org/schema/cache/spring-cache.xsd http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task.xsd">
<context:component-scan base-package="com.xy">
<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
context:component-scan>
<context:property-placeholder location="classpath:context/database.properties"/>
<tx:annotation-driven/>
<bean id="abstractXADataSource" class="com.atomikos.jdbc.AtomikosDataSourceBean" init-method="init"
destroy-method="close" abstract="true">
<property name="xaDataSourceClassName" value="com.mysql.jdbc.jdbc2.optional.MysqlXADataSource"/>
<property name="poolSize" value="10" />
<property name="minPoolSize" value="10"/>
<property name="maxPoolSize" value="30"/>
<property name="borrowConnectionTimeout" value="60"/>
<property name="reapTimeout" value="20"/>
<property name="maxIdleTime" value="60"/>
<property name="maintenanceInterval" value="60"/>
<property name="loginTimeout" value="60"/>
<property name="testQuery">
<value>select 1value>
property>
bean>
<bean id="qadataSource" parent="abstractXADataSource">
<property name="uniqueResourceName" value="mysql/sitestone1" />
<property name="xaDataSourceClassName"
value="com.mysql.jdbc.jdbc2.optional.MysqlXADataSource" />
<property name="xaProperties">
<props>
<prop key="URL">${qa.db.url}prop>
<prop key="user">${qa.db.user}prop>
<prop key="password">${qa.db.password}prop>
<prop key="pinGlobalTxToPhysicalConnection">trueprop>
props>
property>
bean>
<bean id="devdataSource" parent="abstractXADataSource">
<property name="uniqueResourceName" value="mysql/sitestone" />
<property name="xaDataSourceClassName"
value="com.mysql.jdbc.jdbc2.optional.MysqlXADataSource" />
<property name="xaProperties">
<props>
<prop key="URL">${dev.db.url}prop>
<prop key="user">${dev.db.user}prop>
<prop key="password">${dev.db.password}prop>
<prop key="pinGlobalTxToPhysicalConnection">trueprop>
props>
property>
bean>
<bean id="qasqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="qadataSource" />
<property name="mapperLocations" value="classpath*:com/xy/dao/*.xml" />
bean>
<bean id="devsqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="devdataSource" />
<property name="mapperLocations" value="classpath*:com/xy/daodev/*.xml" />
bean>
<bean id="atomikosTransactionManager" class="com.atomikos.icatch.jta.UserTransactionManager"
init-method="init" destroy-method="close">
<property name="forceShutdown">
<value>truevalue>
property>
bean>
<bean id="atomikosUserTransaction" class="com.atomikos.icatch.jta.UserTransactionImp">
<property name="transactionTimeout" value="300" />
bean>
<bean id="transactionManager"
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>
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="com.xy.dao"/>
<property name="sqlSessionFactoryBeanName" value="qasqlSessionFactory" />
bean>
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="com.xy.daodev"/>
<property name="sqlSessionFactoryBeanName" value="devsqlSessionFactory" />
bean>
beans>
database.properties
qa.db.url=jdbc:mysql://localhost:3306/qa?useUnicode=true&characterEncoding=UTF-8
qa.db.user=root
qa.db.password=123456
dev.db.url=jdbc:mysql://localhost:3306/dev?useUnicode=true&characterEncoding=UTF-8
dev.db.user=root
dev.db.password=123456
jta.properties
com.atomikos.icatch.service=com.atomikos.icatch.standalone.UserTransactionServiceFactory
com.atomikos.icatch.console_file_name = tm.out
com.atomikos.icatch.log_base_name = tmlog
com.atomikos.icatch.tm_unique_name = com.atomikos.spring.jdbc.tm
com.atomikos.icatch.console_log_level = INFO
com.atomikos.icatch.output_dir=/hello/atomikos
com.atomikos.icatch.log_base_dir=/hello/atomikos
com.atomikos.icatch.serial_jta_transactions=false
java代码 :
service
package com.xy.service;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import com.xy.dao.NameQaMapper;
import com.xy.daodev.NameDevMapper;
import com.xy.model.NameDev;
import com.xy.model.NameQa;
@Service
public class NameService {
@Autowired
NameQaMapper qaMapper;
@Autowired
NameDevMapper devMapper;
@Transactional(rollbackFor=Exception.class)
public void addQaAndDev(boolean hasException) throws Exception{
NameQa nameQa = new NameQa();
nameQa.setNameQa("hello qa");
qaMapper.insert(nameQa);
NameDev dev = new NameDev();
dev.setNameDev("hello dev");
devMapper.insert(dev);
if (hasException) {
throw new Exception();
}
}
}
controller 代码
package com.xy.controller;
import com.xy.service.NameService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
/**
* Created by helloworld on 2014/11/22.
*/
@Controller
public class mybatisController {
@Autowired
NameService nameService;
@RequestMapping(value = "/addName", method = RequestMethod.GET)
ModelMap addName(@RequestParam("hasException") boolean hasException) {
try {
nameService.addQaAndDev(hasException);
} catch (Exception e) {
e.printStackTrace();
return new ModelMap("false");
}
return new ModelMap("true");
}
}
model 和 mapper 没什么可说的,这里就不粘贴了。