springmvc+mybatis多数据源分布式事务管理

目录

springmvc+mybatis多数据源分布式事务管理

    最近项目用到spring多数据源以进行数据整合，可是配置上事务时，发现数据源不能进行切换，
原因是因为事务是在connection层面管理的，启用事务后，一个事务内部的connection是复用的，
所以就算AOP切了数据源字符串，但是数据源并不会被真正修改，所以决定使用atomikos进行分布式事务的管理。

---

pom依赖

<dependency>
    <groupId>com.atomikos</groupId>
    <artifactId>transactions-jdbc</artifactId>
    <version>3.9.1</version>
</dependency>
<dependency>
    <groupId>javax.transaction</groupId>
    <artifactId>jta</artifactId>
    <version>1.1</version>
</dependency>
<dependency>
    <groupId>cglib</groupId>
    <artifactId>cglib-nodep</artifactId>
    <version>3.2.4</version>
</dependency>

jta.properties

把此配置文件放入classpath路径 项目启动会自动加载 不需进行配置

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  

配置数据源

    为了测试这里配置2个数据源，大家可按自己项目情况配置。

<property name="uniqueResourceName" value="ds1"/>

    注意当配置多个数据源时uniqueResourceName的value不能重复

<bean id="dataSource1" class="com.atomikos.jdbc.AtomikosDataSourceBean" init-               method="init" destroy-method="close">
    <property name="uniqueResourceName" value="ds1"/>
    <property name="xaDataSourceClassName" value="com.mysql.jdbc.jdbc2.optional.MysqlXADataSource"/>
    <property name="xaProperties">
        <props>
            <prop key="url">jdbc:mysql://localhost/test</prop>
            <prop key="user">root</prop>
            <prop key="password">123456</prop>
        </props>
    </property>
    <property name="minPoolSize" value="10" />
    <property name="maxPoolSize" value="100" />
    <property name="borrowConnectionTimeout" value="30" />
    <property name="testQuery" value="select 1" />
    <property name="maintenanceInterval" value="60" />
</bean>

<bean id="dataSource2" class="com.atomikos.jdbc.AtomikosDataSourceBean" init-method="init" destroy-method="close">
    <property name="uniqueResourceName" value="ds2"/>
    <property name="xaDataSourceClassName" value="com.mysql.jdbc.jdbc2.optional.MysqlXADataSource"/>
    <property name="xaProperties">
        <props>
            <prop key="url">jdbc:mysql://localhost/smart-sso</prop>
            <prop key="user">root</prop>
            <prop key="password">123456</prop>
        </props>
    </property>
    <property name="minPoolSize" value="10" />
    <property name="maxPoolSize" value="100" />
    <property name="borrowConnectionTimeout" value="30" />
    <property name="testQuery" value="select 1" />
    <property name="maintenanceInterval" value="60" />
</bean>

配置SQLSessionFactory

    指定mapper文件和实体所在路径

<bean id="sqlSessionFactory1" class="org.mybatis.spring.SqlSessionFactoryBean">
    <property name="dataSource" ref="dataSource1"/>
    <property name="mapperLocations" value="classpath:mapper/*.xml"/>
    <property name="typeAliasesPackage" value="com.fk.entity"/>
</bean>
<bean id="sqlSessionFactory2" class="org.mybatis.spring.SqlSessionFactoryBean">
    <property name="dataSource" ref="dataSource2"/>
    <property name="mapperLocations" value="classpath:mapper/*.xml"/>
    <property name="typeAliasesPackage" value="com.fk.entity"/>
</bean>

配置MapperScanner

    指定dao文件所在包 并指定所用SQlSessionFactory

<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
    <property name="basePackage" value="com.fk.mapperOne" />
    <property name="sqlSessionFactory" ref="sqlSessionFactory1"/>
</bean>
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
    <property name="basePackage" value="com.fk.mapperTwo" />
    <property name="sqlSessionFactory" ref="sqlSessionFactory2"/>
</bean>

配置Jta事务

<bean id="transactionManager" class="org.springframework.transaction.jta.JtaTransactionManager">
    <property name="transactionManager">
        <bean class="com.atomikos.icatch.jta.UserTransactionManager" init-method="init" destroy-method="close">
            <property name="forceShutdown" value="true"/>
        </bean>
    </property>
    <property name="userTransaction">
        <bean class="com.atomikos.icatch.jta.UserTransactionImp"/>
    </property>
</bean>

    最后加上声明式注解支持

    <tx:annotation-driven/>

    数据源和事务配置已经完成，接下来就是测试分布式事务是否可用了。

实体

为了测试方便 这里2个数据源使用的是一个实体

public class Student {
    private Integer id;
    private String name;
    private Integer age;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }
}

dao

    这里两个mapper分别在配置MapperScanner配置的包体里

package com.fk.mapperOne;

import com.fk.entity.Student;
import org.springframework.stereotype.Repository;

@Repository
public interface StudentOneMapper {
    void insert(Student student);
}

package com.fk.mapperTwo;

import com.fk.entity.Student;
import org.springframework.stereotype.Repository;

@Repository
public interface StudentTwoMapper {
    void insert(Student student);
}

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.fk.mapperOne.StudentOneMapper" >
    <insert id="insert" parameterType="com.fk.entity.Student">
        insert into student(id,name,age) values (#{id},#{name},#{age})
    </insert>
</mapper>

<?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.fk.mapperTwo.StudentTwoMapper" >
    <insert id="insert" parameterType="com.fk.entity.Student">
        insert into student(id,name,age) values (#{id},#{name},#{age})
    </insert>
</mapper>

service

package com.fk.service;

import com.fk.entity.Student;
import com.fk.mapperOne.StudentOneMapper;
import com.fk.mapperTwo.StudentTwoMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

@Service
public class StudentServiceImpl {

@Autowired
private StudentOneMapper studentOneMapper;

@Autowired
private StudentTwoMapper studentTwoMapper;

@Transactional
public void insert() throws Exception{
    Student student = new Student();
    student.setId(1);
    student.setName("Nancy");
    student.setAge(12);

    studentOneMapper.insert(student);

    student = new Student();
    student.setId(1);
    student.setName("Tom");
    student.setAge(2);
    studentTwoMapper.insert(student);
}

}

Junit测试

接下来使用junit进行测试

import com.fk.service.StudentServiceImpl;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = { "classpath:/spring/spring-mvc.xml",
        "classpath:/spring/spring-mybatis.xml"})
public class StudentJunit {

    @Autowired
    private StudentServiceImpl studentService;
    @Test
    public void TestInsert(){
        try {
            studentService.insert();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

先测试下是否能插入数据

可以看到2个数据库里都已经插入一条数据

接下来在测试下异常是否会回滚

@Transactional
    public void insert() throws Exception{
        Student student = new Student();
        student.setId(2);
        student.setName("Nancy");
        student.setAge(12);

        studentOneMapper.insert(student);

        student = new Student();
        student.setId(1);
        student.setName("Tom");
        student.setAge(2);
        studentTwoMapper.insert(student);
    }

    将第一个插入实体的ID加1，保持第二个实体不变，因为表里有设置主键，这样第二条插入时，
会出现主键重复异常，以此来测试第一条插入语句是否会回滚。

如我们所愿，主键重复，接下来看下数据是否有插入

yes！数据没有插入，则证明事务已回滚了。

完结

分布式事务的内容就是这些了，由于本人初次接触分布式事务，有不足之处还请谅解并指出，谢谢！
 [完整Demo](http://git.oschina.net/monsterjava/fk_demo/tree/feature_fk/)