两种数据源的配置

   本人是S2SH 开发，由于业务的需要，需要配置二种不同的数据源，并且二种数据源要进行不断的切换，一是mysql，另一是orcale。下面就简单的介绍下二种不同的数据源的配法。

    首先在spring 的context配置文件中配置二种不同的数据源：

   <?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:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd"> <bean id="dataSource" class="com.db.dbcp.SystemDataSource" destroy-method="close"> <property name="driverClassName"> <value>oracle.jdbc.driver.OracleDriver</value> </property> <property name="url"> <value>jdbc:oracle:thin:@dbhost:1521:service</value> </property> <property name="username"> <value>tiger</value> </property> <property name="password"> <value>scotter</value> </property> <!-- 初始化连接 --> <property name="initialSize"> <value>1</value> </property> <property name="maxActive"> <value>5</value> </property> <!-- 最大空闲连接 --> <property name="maxIdle"> <value>5</value> </property> <property name="minIdle"> <value>1</value> </property> <!-- 超时等待时间以毫秒为单位 --> <property name="maxWait"> <value>1000</value> </property> <!-- 是否自动回收超时连接 --> <property name="removeAbandoned"> <value>true</value> </property> <property name="removeAbandonedTimeout"> <value>2000</value> </property> </bean> <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate"> <property name="dataSource" ref="dataSource" /> </bean> <bean id="mysqlTemplate" class="org.springframework.jdbc.core.JdbcTemplate"> <property name="dataSource" ref="mysqlDataSource"/> </bean> <bean id="mysqlHibernateTemplate" class="org.springframework.orm.hibernate3.HibernateTemplate"> <property name="sessionFactory" ref="mysqlSessionFactory" /> </bean> <bean id="mysqlDataSource" class="com.db.dbcp.SystemDataSource" destroy-method="close"> <property name="driverClassName"> <value>org.gjt.mm.mysql.Driver</value> </property> <property name="url"> <value>jdbc:mysql://localhost:3306/test?autoReconnect=true&useUnicode=true&characterEncoding=UTF8&zeroDateTimeBehavior=convertToNull</value> </property> <property name="username"> <value>root</value> </property> <property name="password"> <value>123456</value> </property> <!-- 初始化连接 --> <property name="initialSize"> <value>1</value> </property> <property name="maxActive"> <value>5</value> </property> <!-- 最大空闲连接 --> <property name="maxIdle"> <value>5</value> </property> <property name="minIdle"> <value>1</value> </property> <!-- 超时等待时间以毫秒为单位 --> <property name="maxWait"> <value>1000</value> </property> <!-- 是否自动回收超时连接 --> <property name="removeAbandoned"> <value>true</value> </property> <property name="removeAbandonedTimeout"> <value>2000</value> </property> </bean> <bean id="mysqlSessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean"> <property name="dataSource"> <ref local="mysqlDataSource" /> </property> <property name="mappingManager"> <ref bean="mysqlMappingManager" /> </property> <property name="hibernateProperties"> <props> <prop key="hibernate.dialect"> org.hibernate.dialect.MySQLDialect </prop> <prop key="hibernate.show_sql">true</prop> <prop key="hibernate.max_fetch_depth">0</prop> <prop key="hibernate.default_batch_fetch_size">6</prop> <prop key="hibernate.default_entity_mode">pojo</prop> <prop key="hibernate.generate_statistics">false</prop> <prop key="hibernate.jdbc.batch_size">20</prop> <prop key="hibernate.jdbc.fetch_size">30</prop> <prop key="hibernate.cache.use_second_level_cache"> true </prop> </props> </property> <property name="mappingDirectoryLocations"> <list> <value>classpath:/com/test/ssh/mapping/mysql</value> </list> </property> </bean> <bean id="oracleSessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean"> <property name="dataSource"> <ref local="dataSource" /> </property> <property name="mappingManager"> <ref bean="mappingManager" /> </property> <property name="hibernateProperties"> <props> <prop key="hibernate.dialect"> org.hibernate.dialect.OracleDialect </prop> <prop key="hibernate.show_sql">true</prop> <prop key="hibernate.max_fetch_depth">0</prop> <prop key="hibernate.default_batch_fetch_size">6</prop> <prop key="hibernate.default_entity_mode">pojo</prop> <prop key="hibernate.generate_statistics">false</prop> <prop key="hibernate.jdbc.batch_size">20</prop> <prop key="hibernate.jdbc.fetch_size">30</prop> <prop key="hibernate.cache.use_second_level_cache"> true </prop> </props> </property> <property name="mappingDirectoryLocations"> <list> <value>classpath:/com/test/ssh/mapping/mysql</value> </list> </property> </bean> <bean id="sessionFactory" class="com.test.s2sh.common.MultiSessionFactory"> <property name="sessionFactory"> <ref bean="oracleSessionFactory"/> </property> </bean> </beans>

  二种数据源和sessionFactory 都已经配置完毕，接下来就是调用的问题了。

  要保证二个数据源中的二个sessionFactory 只能有一个是可用状态并且还可以相互切换。需要写个java类 MultiSessionFactory

 代码如下：

  public class MultiSessionFactory implements SessionFactory, ApplicationContextAware { private static final long serialVersionUID = 2064557324203496378L; 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) { try{ if(sessionFactoryName==null||sessionFactoryName.equals("")){ return sessionFactory; } return (SessionFactory)this.getApplicationContext().getBean(sessionFactoryName); }catch(NoSuchBeanDefinitionException ex){ System.out.println(sessionFactoryName+" =====>NoSuchBeanDefinition"); ex.printStackTrace(); return null; } } public SessionFactory getSessionFactory() { String sessionFactoryName = SessionUtiles.getCurrentSessionFactory(); 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(); } }

 再写个线程安全类，保证只有一个sessionFactory 是有用的。

 public class SessionUtiles { private static ThreadLocal local = new ThreadLocal(); public static void setCurrentSessionFactory(String session) { System.out.println("sessionFactory name:"+session); local.set(session); } public static String getCurrentSessionFactory() { return (String)local.get(); } }

 如此 基本上配置完成，只需要在dao实现方法里面进行切换操作就可以了。

 在dao开始和结束的时候调用 SessionUtiles.setCurrentSessionFactory("mysqlSessionFactory");或者SessionUtiles.setCurrentSessionFactory("oracleSessionFactory");

经过如上配置和操作，就可以随意切换不同的数据源了。