适用范围åQšé€‚合SSH架构讉K—®å¤šä¸ªæ•°æ®åº“，数据库的¾cÕdž‹å’Œè¡¨¾l“构不必相同åQŒä¸”没有跨库事务的情况（跨库事务最好用分布式事务处理）ã€?/p>

<!-- Hibernate SessionFactorys -->
<bean id="aSessionFactory"
   class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
   <property name="dataSource">
    <ref local="aDataSource" />
   </property>
   <property name="mappingResources">
    <list>
     <value>
      .hbm.xmlæ–‡äšg
     </value>
    </list>
   </property>
   <property name="hibernateProperties">
    <props>
     <prop key="hibernate.dialect">
      ${ahibernate.dialect}
     </prop>
     <prop key="hibernate.show_sql">true</prop>
     <prop key="format_sql">true</prop>
    </props>
   </property>
</bean>

<bean id="bSessionFactory"
   class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
   <property name="dataSource">
    <ref local="bDataSource" />
   </property>
   <property name="mappingResources">
    <list>
     <value>
      .hbm.xmlæ–‡äšg
     </value>
    </list>
   </property>
   <property name="hibernateProperties">
    <props>
     <prop key="hibernate.dialect">
      ${bhibernate.dialect}
     </prop>
     <prop key="hibernate.show_sql">true</prop>
     <prop key="format_sql">true</prop>
    </props>
   </property>
</bean>

<bean id="cSessionFactory"
   class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
   <property name="dataSource">
    <ref local="cDataSource" />
   </property>
   <property name="mappingResources">
    <list>
     <value>
       .hbm.xmlæ–‡äšg
     </value>
    </list>
   </property>
   <property name="hibernateProperties">
    <props>
     <prop key="hibernate.dialect">
      ${chibernate.dialect}
     </prop>
     <prop key="hibernate.show_sql">true</prop>
     <prop key="format_sql">true</prop>
    </props>
   </property>
</bean>

<bean id="sessionFactory" class="com.cintel.dcp.datasource.MultiSessionFactory">
   <property name="sessionFactory"><ref local="aSessionFactory"/></property>
</bean>
注意åQ?font color="#ff0000">最后一ä¸?font color="#0000ff">com.cintel.dcp.datasource.MultiSessionFactory要自己实玎ͼŒå®ƒå®žçŽîCº†SessionFactory接口和ApplicationContext接口åQŒå¦‚下：
package com.cintel.dcp.datasource;

import java.io.Serializable;
import java.sql.Connection;
import java.util.Map;
import java.util.Set;

import javax.naming.NamingException;
import javax.naming.Reference;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.hibernate.HibernateException;
import org.hibernate.Interceptor;
import org.hibernate.SessionFactory;
import org.hibernate.StatelessSession;
import org.hibernate.classic.Session;
import org.hibernate.engine.FilterDefinition;
import org.hibernate.metadata.ClassMetadata;
import org.hibernate.metadata.CollectionMetadata;
import org.hibernate.stat.Statistics;
import org.springframework.beans.factory.NoSuchBeanDefinitionException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;

public class MultiSessionFactory implements SessionFactory, ApplicationContextAware {
private static final long serialVersionUID = 2064557324203496378L;
private static final Log log = LogFactory.getLog(MultiSessionFactory.class);
private ApplicationContext applicationContext = null;
private SessionFactory sessionFactory = null;

public ApplicationContext getApplicationContext() {
   return applicationContext;
}

public void setApplicationContext(ApplicationContext applicationContext) {
   this.applicationContext = applicationContext;
}

public SessionFactory getSessionFactory(String sessionFactoryName) {
   log.debug("sessionFactoryName:"+sessionFactoryName);
   try{
    if(sessionFactoryName==null||sessionFactoryName.equals("")){
     return sessionFactory;
    }
    return (SessionFactory)this.getApplicationContext().getBean(sessionFactoryName);
   }catch(NoSuchBeanDefinitionException ex){
    throw new RuntimeException("There is not the sessionFactory <name:"+sessionFactoryName+"> in the applicationContext!");
   }
}

public SessionFactory getSessionFactory() {
   String sessionFactoryName = CustomerContextHolder.getCustomerType();
   return getSessionFactory(sessionFactoryName);
}

public void setSessionFactory(SessionFactory sessionFactory) {
   this.sessionFactory = sessionFactory;
}


/* (non-Javadoc)
* @see org.hibernate.SessionFactory#close()
*/
public void close() throws HibernateException {
   getSessionFactory().close();
}
/* (non-Javadoc)
* @see org.hibernate.SessionFactory#evict(java.lang.Class)
*/
public void evict(Class persistentClass) throws HibernateException {
   getSessionFactory().evict(persistentClass);
}
/* (non-Javadoc)
* @see org.hibernate.SessionFactory#evict(java.lang.Class, java.io.Serializable)
*/
public void evict(Class persistentClass, Serializable id) throws HibernateException {
   getSessionFactory().evict(persistentClass, id);
}
/* (non-Javadoc)
* @see org.hibernate.SessionFactory#evictCollection(java.lang.String)
*/
public void evictCollection(String roleName) throws HibernateException {
   getSessionFactory().evictCollection(roleName);
}
/* (non-Javadoc)
* @see org.hibernate.SessionFactory#evictCollection(java.lang.String, java.io.Serializable)
*/
public void evictCollection(String roleName, Serializable id) throws HibernateException {
   getSessionFactory().evictCollection(roleName, id);
}
/* (non-Javadoc)
* @see org.hibernate.SessionFactory#evictEntity(java.lang.String)
*/
public void evictEntity(String entityName) throws HibernateException {
   getSessionFactory().evictEntity(entityName);
}
/* (non-Javadoc)
* @see org.hibernate.SessionFactory#evictEntity(java.lang.String, java.io.Serializable)
*/
public void evictEntity(String entityName, Serializable id) throws HibernateException {
   getSessionFactory().evictEntity(entityName, id);
}
/* (non-Javadoc)
* @see org.hibernate.SessionFactory#evictQueries()
*/
public void evictQueries() throws HibernateException {
   getSessionFactory().evictQueries();
}
/* (non-Javadoc)
* @see org.hibernate.SessionFactory#evictQueries(java.lang.String)
*/
public void evictQueries(String cacheRegion) throws HibernateException {
   getSessionFactory().evictQueries(cacheRegion);
}
/* (non-Javadoc)
* @see org.hibernate.SessionFactory#getAllClassMetadata()
*/
public Map getAllClassMetadata() throws HibernateException {
   return getSessionFactory().getAllClassMetadata();
}
/* (non-Javadoc)
* @see org.hibernate.SessionFactory#getAllCollectionMetadata()
*/
public Map getAllCollectionMetadata() throws HibernateException {
   return getSessionFactory().getAllCollectionMetadata();
}
/* (non-Javadoc)
* @see org.hibernate.SessionFactory#getClassMetadata(java.lang.Class)
*/
public ClassMetadata getClassMetadata(Class persistentClass) throws HibernateException {
   return getSessionFactory().getClassMetadata(persistentClass);
}
/* (non-Javadoc)
* @see org.hibernate.SessionFactory#getClassMetadata(java.lang.String)
*/
public ClassMetadata getClassMetadata(String entityName) throws HibernateException {
   return getSessionFactory().getClassMetadata(entityName);
}
/* (non-Javadoc)
* @see org.hibernate.SessionFactory#getCollectionMetadata(java.lang.String)
*/
public CollectionMetadata getCollectionMetadata(String roleName) throws HibernateException {
   return getSessionFactory().getCollectionMetadata(roleName);
}
/* (non-Javadoc)
* @see org.hibernate.SessionFactory#getCurrentSession()
*/
public Session getCurrentSession() throws HibernateException {
   return getSessionFactory().getCurrentSession();
}
/* (non-Javadoc)
* @see org.hibernate.SessionFactory#getDefinedFilterNames()
*/
public Set getDefinedFilterNames() {
   return getSessionFactory().getDefinedFilterNames();
}
/* (non-Javadoc)
* @see org.hibernate.SessionFactory#getFilterDefinition(java.lang.String)
*/
public FilterDefinition getFilterDefinition(String filterName) throws HibernateException {
   return getSessionFactory().getFilterDefinition(filterName);
}
/* (non-Javadoc)
* @see org.hibernate.SessionFactory#getStatistics()
*/
public Statistics getStatistics() {
   return getSessionFactory().getStatistics();
}
/* (non-Javadoc)
* @see org.hibernate.SessionFactory#isClosed()
*/
public boolean isClosed() {
   return getSessionFactory().isClosed();
}
/* (non-Javadoc)
* @see org.hibernate.SessionFactory#openSession()
*/
public Session openSession() throws HibernateException {
   return getSessionFactory().openSession();
}
/* (non-Javadoc)
* @see org.hibernate.SessionFactory#openSession(java.sql.Connection)
*/
public Session openSession(Connection connection) {
   return getSessionFactory().openSession(connection);
}
/* (non-Javadoc)
* @see org.hibernate.SessionFactory#openSession(org.hibernate.Interceptor)
*/
public Session openSession(Interceptor interceptor) throws HibernateException {
   return getSessionFactory().openSession(interceptor);
}
/* (non-Javadoc)
* @see org.hibernate.SessionFactory#openSession(java.sql.Connection, org.hibernate.Interceptor)
*/
public Session openSession(Connection connection, Interceptor interceptor) {
   return getSessionFactory().openSession(connection, interceptor);
}
/* (non-Javadoc)
* @see org.hibernate.SessionFactory#openStatelessSession()
*/
public StatelessSession openStatelessSession() {
   return getSessionFactory().openStatelessSession();
}
/* (non-Javadoc)
* @see org.hibernate.SessionFactory#openStatelessSession(java.sql.Connection)
*/
public StatelessSession openStatelessSession(Connection connection) {
   return getSessionFactory().openStatelessSession(connection);
}
/* (non-Javadoc)
* @see javax.naming.Referenceable#getReference()
*/
public Reference getReference() throws NamingException {
   return getSessionFactory().getReference();
}
}

然后我用一个常量类来标识sessionFactory
public class DynamicDataSourceType {
public static final String A= "aSessionFactory";
public static final String B= "bSessionFactory";
public static final String C= "cSessionFactory";
}

最后一个关键类åQšç”¨æ¥å­˜æ”‘Ö½“前正在ä‹É用的sessionFactory
public class CustomerContextHolder {

private static final ThreadLocal contextHolder = new ThreadLocal();

public static void setCustomerType(String customerType) {
   Assert.notNull(customerType, "customerType cannot be null");
   contextHolder.set(customerType);
}

public static String getCustomerType() {
   return (String) contextHolder.get();
}

public static void clearCustomerType() {
   contextHolder.remove();
}
}

可以在action、service、dao中进行数据库切换åQŒåˆ‡æ¢æ–¹å¼ï¼š
CustomerContextHolder.setCustomerType(DynamicDataSourceType.A);

以上思èµ\来自javaEye论坛的一个高手，在此标识感谢

文章来源åQ?/strong>

http://www.th7.cn/Program/java/2011/10/23/44664.shtml

èµ·å› åQšåœ¨å½“前我手上的一个项目中需要多个数据源,òq¶ä¸”来自于不同类型的数据åº?.. å› äؓ很多历史原因.˜q™ä¸ª™å¹ç›®çš„住数据源是MySQL,整个¾pȝ»Ÿçš„CURD都是操作的这个数据库.

但是˜q˜æœ‰å¦å¤–两个用于数据采集的数据库: MSSQL,ACCESS.˜q˜å¥½åªæ˜¯ç”¨äºŽæ•°æ®é‡‡é›†åQŒåœ¨äº‹åŠ¡ä¸Šå¯ä»¥ä¸è¦è·¨æ•°æ®åº“了åQŒè¿™ä¸€ç‚¹èŠ‚省了好多的工作量.环境åQšæˆ‘搭徏的测试环境是 spring2.5.6+hibernate3.2
思èµ\åQšåŠ¨æ€åˆ‡æ¢æ•°æ®æº¼‹®åˆ‡çš„来说是在同一¾cÕdž‹æ•°æ®åº“的情况下的。意思就是说 , 在系¾lŸä¸­çš„ä‹É用的数据库分布在多台数据库服务器或者在同台服务器上的多个数据库. 在运行时期间æ ÒŽ®æŸç§æ ‡è¯†½W¦æ¥åŠ¨æ€çš„选择当前操作的数据库.     1.数据源是相同¾cÕdž‹çš„数据库: 一个SessionFactory+动态数据源+一个事务管理器     2.数据源是不同¾cÕdž‹çš„数据库: æ ÒŽ®¾cÕdž‹ 配置多套SessionFactory模拟åQšä¸¤ä¸ªmysql数据æº?一个Access数据æº?/span>
实现åQ?/span>
1.切换数据源需要标识符,标识½W¦æ˜¯Object¾cÕdž‹

package lhp.example.context;
public enum DBType {
      dataSource1, dataSource2;
}

2.然后创徏一个用于切换数据源(讄¡½®æˆ–者获得上下文)çš„å·¥å…ïL±»

package lhp.example.context;

public class ContextHolder {
    private static final ThreadLocal<Object> holder = new ThreadLocal<Object>();

    public static void setDbType(DBType dbType) {
        holder.set(dbType);
    }

    public static DBType getDbType() {
        return (DBType) holder.get();
    }

    public static void clearDbType() {
        holder.remove();
    }
}

3.创徏动态数据源¾c?¾l§æ‰¿org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource˜q™ä¸ª¾c?

package lhp.example.context;

import java.util.logging.Logger;

import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;

public class DynamicDataSource extends AbstractRoutingDataSource {
    public static final Logger logger = Logger.getLogger(DynamicDataSource.class.toString());

    @Override
    protected Object determineCurrentLookupKey() {
        DBType key = ContextHolder.getDbType();//获得当前数据源标识符
        //logger.info("当前数据�:" + key);
        return key;
    }

}

4.然后配置多个数据�/span>

<!-- 数据æº? åQ?mysql -->
    <bean id="dataSource1" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="com.mysql.jdbc.Driver" />
        <property name="jdbcUrl" value="jdbc:mysql://127.0.0.1:3306/dec" />
        <property name="user" value="root" />
        <property name="password" value="" />
    </bean>
    <!-- 数据æº? åQ?mysql  -->
    <bean id="dataSource2" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="com.mysql.jdbc.Driver" />
        <property name="jdbcUrl" value="jdbc:mysql://127.0.0.1:3306/lms" />
        <property name="user" value="root" />
        <property name="password" value="" />
    </bean>

    <!-- 数据æº? åQ? access -->
    <bean id="dataSource3" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="sun.jdbc.odbc.JdbcOdbcDriver" />
        <property name="jdbcUrl" value="jdbc:odbc:accessTest" />
        <property name="user" value="administrator" />
        <property name="password" value="XLZX0309" />
    </bean>

    <!-- mysql 动态数据源讄¡½®-->
    <bean id="mysqlDynamicDataSource" class="lhp.example.context.DynamicDataSource">
        <property name="targetDataSources">
            <!-- 标识½W¦ç±»åž?-->
            <map key-type="lhp.example.context.DBType">
                <entry key="dataSource1" value-ref="dataSource1" />
                <entry key="dataSource2" value-ref="dataSource2" />
            </map>
        </property>
        <property name="defaultTargetDataSource" ref="dataSource1" />
    </bean>
    

5.配置sessionFactory

<!-- mysql sessionFactory -->
    <bean id="mysqlSessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
        <property name="dataSource" ref="mysqlDynamicDataSource" />
        <property name="hibernateProperties">
            <props>
                <prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
                <prop key="hibernate.show_sql">true</prop>
                <prop key="hibernate.hbm2ddl.auto">update</prop><!--create validate -->
                <prop key="hibernate.query.substitutions">true 1, false 0</prop>
            </props>
        </property>
    </bean>
    
    <!-- access sessionFactory -->
    <bean id="aceessSessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
        <property name="dataSource" ref="dataSource3" />
        <property name="hibernateProperties">
            <props>
                <!-- access 语法和MSSQLç›æ€¼¼ 所以用的MSSQL方言åQŒæˆ–者可以ä‹É用第三方方言 -->
                <prop key="hibernate.dialect">org.hibernate.dialect.SQLServerDialect</prop>
                <prop key="hibernate.jdbc.batch_size">30</prop>
                <prop key="hibernate.jdbc.fetch_size">50</prop>
                <prop key="hibernate.show_sql">true</prop>
                <prop key="hibernate.format_sql">false</prop>
                <prop key="hibernate.hbm2ddl.auto">update</prop><!--create validate -->
                <prop key="hibernate.query.substitutions">true 1, false 0</prop>
                <prop key="hibernate.cglib.use_reflection_optimizer">true</prop>
                <!-- <prop key="hibernate.cache.use_second_level_cache">true</prop> -->
                <!-- <prop key="hibernate.cache.provider_class">org.hibernate.cache.EhCacheProvider</prop> -->
                <!-- <prop key="hibernate.cache.use_query_cache">true</prop> -->
                <!-- <prop key="hibernate.generate_statistics">true</prop> -->
                <!-- <prop key="hibernate.cache.provider_configuration_file_resource_path">classpath:ehcache.xml</prop> -->
            </props>
        </property>
    </bean>

6.‹¹‹è¯•ç”¨ä¾‹

package lhp.example.junit;

import static org.junit.Assert.*;
import java.sql.DatabaseMetaData;
import lhp.example.context.ContextHolder;
import lhp.example.context.DBType;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.junit.Before;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class ServiceTest {
    private ApplicationContext context;
    //三个数据源的URL
    private String dataSource1_URL = "jdbc:mysql://127.0.0.1:3306/dec";
    private String dataSource2_URL = "jdbc:mysql://127.0.0.1:3306/lms";
    private String dataSource3_URL = "jdbc:odbc:accessTest";
    private SessionFactory mysqlSessionFactory;
    private SessionFactory aceessSessionFactory;

    @Before
    public void setUp() throws Exception {
        // 选择数据源初始化spring
        ContextHolder.setDbType(DBType.dataSource1);
        //
        String[] xmlFiles = new String[] { 
                "applicationContext-dataSource.xml",
                "applicationContext-hibernate.xml",
                "applicationContext-spring.xml" };
        //
        context = new ClassPathXmlApplicationContext(xmlFiles);
        //
        mysqlSessionFactory = (SessionFactory) context.getBean("mysqlSessionFactory");
        aceessSessionFactory = (SessionFactory) context.getBean("aceessSessionFactory");
    }

    @SuppressWarnings("deprecation")
    @Test
    public void mysqlDataSourceTest() {
        try {

            Session mysqlSession = mysqlSessionFactory.openSession();
            // 获得数据库元数据
            DatabaseMetaData meatData = mysqlSession.connection().getMetaData();

            // 默认启动数据�dataSource1
            //断言当前数据源URL是否是dataSource1的URL
            assertEquals(dataSource1_URL, meatData.getURL());

            // 切换到数据源 dataSource2
            ContextHolder.setDbType(DBType.dataSource2);
            mysqlSession = mysqlSessionFactory.openSession();
            meatData = mysqlSession.connection().getMetaData();
            //断言当前数据源URL是否是dataSource2的URL
            assertEquals(dataSource2_URL, meatData.getURL());

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    
    @SuppressWarnings("deprecation")
    @Test
    public void accessDataSourceTest() {
        try {
            Session accessSession = aceessSessionFactory.openSession();
            // 获得数据库元数据
            DatabaseMetaData meatData = accessSession.connection().getMetaData();
            //断言当前数据源URL是否是dataSource3的URL
            assertEquals(dataSource3_URL, meatData.getURL());


        } catch (Exception e) {
            e.printStackTrace();
        }
    }

}

GavinMiao 2011-11-14 15:37 发表评论

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