spring + atomikos解决多数据源事务管理

     一般的企业管理系统免不了要访问多个数据库，如框架数据库、仓库数据库等，但spring的jdbc事务只支持一个数据源的事务配置，为了在tomcat中支持多数据源事务，可以采用开源框架atomikos来进行配置。

采用的开发环境:Spring4 + hibernate4 + atomikos3.9.3 + mssql2008

1.下载atomikos-jdbc:3.9.1

所需要的包如下：

2.下载sqljdbc4.jar

有关mssql的XA支持，请参考下面：

https://technet.microsoft.com/zh-cn/library/aa342335.aspx

 3.Spring atomikos事务配置

配置两个xa数据源xaDataSource，两个SessionFactory

<?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:context="http://www.springframework.org/schema/context"
	xmlns:tx="http://www.springframework.org/schema/tx"
	xmlns:aop="http://www.springframework.org/schema/aop"
	
	xsi:schemaLocation="http://www.springframework.org/schema/beans 
	http://www.springframework.org/schema/beans/spring-beans-3.1.xsd 
	http://www.springframework.org/schema/tx 
	http://www.springframework.org/schema/tx/spring-tx.xsd
	http://www.springframework.org/schema/context 
    http://www.springframework.org/schema/context/spring-context-3.1.xsd
    http://www.springframework.org/schema/aop
    http://www.springframework.org/schema/aop/spring-aop-3.1.xsd" 
	>
    <context:component-scan base-package="com.framework.dao"/>
    <context:component-scan base-package="com.framework.dao.mssql"/>
    <context:component-scan base-package="com.framework.service"/>
    <context:component-scan base-package="com.framework.action"/>

    <context:component-scan base-package="com.stk.dao.mssql"/>
    <context:component-scan base-package="com.stk.service"/>
    <context:component-scan base-package="com.stk.action"/>
    
    
    <bean id="propertyConfigurer"
          class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="location" value="classpath:framework.properties"/>
    </bean>

    <bean class="com.atomikos.jdbc.AtomikosDataSourceBean" init-method="init" destroy-method="close"
          id="datasourceFW">
        <property name="uniqueResourceName"><value>framework</value></property>
        <property name="xaDataSourceClassName" value="com.microsoft.sqlserver.jdbc.SQLServerXADataSource" />
        <property name="xaProperties">
            <props>
                <prop key="user">${jdbc.username}</prop>
                <prop key="password">${jdbc.password}</prop>
                <prop key="URL">${jdbc.url}</prop>
            </props>
        </property>

    </bean>


    <bean id="sessionFactoryFW"
          class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
        <property name="dataSource" ref="datasourceFW"/>
        <!--  -->
        <property name="packagesToScan" value="com.framework.domain"/>
        
        <property name="hibernateProperties">
            <props>
                <prop key="hibernate.dialect">com.util.SQLServerDialect</prop>
                <prop key="hibernate.show_sql">true</prop>
                <prop key="hibernate.current_session_context_class">jta</prop>
                <prop key="hibernate.transaction.factory_class">org.hibernate.engine.transaction.internal.jta.JtaTransactionFactory</prop>
            </props>
        </property>
    </bean>
    <bean id="hibernateTemplateFW"
          class="org.springframework.orm.hibernate4.HibernateTemplate"
          p:sessionFactory-ref="sessionFactoryFW" />
    <bean class="com.atomikos.jdbc.AtomikosDataSourceBean" init-method="init" destroy-method="close"
          id="datasourceStk">
        <property name="uniqueResourceName"><value>stk</value></property>
        <property name="xaDataSourceClassName" value="com.microsoft.sqlserver.jdbc.SQLServerXADataSource" />
        <property name="xaProperties">
            <props>
                <prop key="user">${jdbcstk.username}</prop>
                <prop key="password">${jdbcstk.password}</prop>
                <prop key="URL">${jdbcstk.url}</prop>
            </props>
        </property>

    </bean>


    <bean id="sessionFactoryStk"
          class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
        <property name="dataSource" ref="datasourceStk"/>
        <!--  -->
        <property name="packagesToScan" value="com.stk.domain"/>

        <property name="hibernateProperties">
            <props>
                <prop key="hibernate.dialect">com.util.SQLServerDialect</prop>
                <prop key="hibernate.show_sql">true</prop>
                <prop key="hibernate.current_session_context_class">jta</prop>
                <prop key="hibernate.transaction.factory_class">org.hibernate.engine.transaction.internal.jta.JtaTransactionFactory</prop>
                <!--  4.0
                <prop key="hibernate.cache.region.factory_class">org.hibernate.cache.ehcache.EhCacheRegionFactory</prop>
                <prop key="hibernate.cache.use_second_level_cache">true</prop>-->

            </props>
        </property>
    </bean>
    <bean id="hibernateTemplateStk"
          class="org.springframework.orm.hibernate4.HibernateTemplate"
          p:sessionFactory-ref="sessionFactoryStk" />

    <!-- atomikos事务管理器 -->
    <bean id="atomikosTransactionManager" class="com.atomikos.icatch.jta.UserTransactionManager"
          init-method="init" destroy-method="close">
        <description>UserTransactionManager</description>
        <property name="forceShutdown">
            <value>true</value>
        </property>
    </bean>

    <bean id="atomikosUserTransaction" class="com.atomikos.icatch.jta.UserTransactionImp">
        <property name="transactionTimeout" value="300" />
    </bean>

    <!-- spring 事务管理器 -->
    <bean id="transactionManager"
          class="org.springframework.transaction.jta.JtaTransactionManager">
        <property name="transactionManager" ref="atomikosTransactionManager"/>
        <property name="userTransaction" ref="atomikosUserTransaction" />
        <property name="allowCustomIsolationLevels" value="true"/>
    </bean>

      <tx:advice id="txAdvice" transaction-manager="transactionManager">
        <tx:attributes>
            <tx:method name="select*" read-only="true" propagation="REQUIRED"/>
            <tx:method name="get*" read-only="true" propagation="REQUIRED"/>
            <tx:method name="load*" read-only="true" propagation="REQUIRED"/>
            <tx:method name="find*" read-only="true" propagation="REQUIRED"/>
            <tx:method name="query*" read-only="true" propagation="REQUIRED"/>
            <tx:method name="read*" read-only="true" propagation="REQUIRED"/>
            <tx:method name="sync*"/>
            <tx:method name="*" propagation="REQUIRED" rollback-for="Exception"/>
        </tx:attributes>
    </tx:advice>
    <aop:config>
        <aop:pointcut id="pointcut" expression="execution(* com.framework.service.*.*(..))"/>
        <aop:advisor advice-ref="txAdvice" pointcut-ref="pointcut"/>
    </aop:config>
   </beans>

 4.Spring DAO设计

采用SessionFactory注入的方式（不能采用HibernateTemplate)

 BaseDao设计,session的管理，采用 ThreadLocal进行保存和获取，保证同一线程获取一次，

注意，数据操作之后要调用session.flush()进行保存。

/**
 * DAO基类，其它DAO可以直接继承这个DAO，不但可以复用共用的方法，还可以获得泛型的好处。
 */
public abstract class BaseDao<T> {
    ThreadLocal<Session> localSession = new ThreadLocal<Session>();

    private Class<T> entityClass;

    public abstract SessionFactory getSessionFactory();

    /**
     * 通过反射获取子类确定的泛型类
     */
    public BaseDao() {
        Type genType = getClass().getGenericSuperclass();
        Type[] params = ((ParameterizedType) genType).getActualTypeArguments();
        entityClass = (Class) params[0];
    }

    /**
     * 根据ID加载PO实例
     *
     * @param id
     * @return 返回相应的持久化PO实例
     */
    public T load(Serializable id) {
        return (T) getSession().load(entityClass, id);
    }

    /**
     * 根据ID获取PO实例
     *
     * @param id
     * @return 返回相应的持久化PO实例
     */
    public T get(Serializable id) {
        return (T) getSession().get(entityClass, id);
    }


    /**
     * 保存PO
     *
     * @param entity
     */
    public void save(T entity) {
        Session session = getSession();
        session.save(entity);
        session.flush();
    }

    public void saveOrUpdate(T entity) {
        Session session = getSession();
        session.saveOrUpdate(entity);
        session.flush();
    }

    /**
     * 删除PO
     *
     * @param entity
     */
    public void remove(T entity) {
        Session session = getSession();
        session.delete(entity);
        session.flush();
    }

    /**
     * 更改PO
     *
     * @param entity
     */
    public void update(T entity) {
        Session session = getSession();
        session.update(entity);
        session.flush();
    }

   
    public Query createSqlQuery(String sql, Object... values) {
        Assert.hasText(sql);
        Query query = getSession().createSQLQuery(sql);
        for (int i = 0; i < values.length; i++) {
            query.setParameter(i, values[i]);
        }
        return query;
    }

    public Session getSession() {

        //Session session =getSessionFactory().getCurrentSession();
        //if (session == null)
        Session session = localSession.get();
        if(session == null) {
            session = getSessionFactory().openSession();
            localSession.set(session);
        }
        return session;
    }


}