spring配置多数据源

项目中我们经常会遇到多数据源的问题，尤其是数据同步或定时任务等项目更是如此。多数据源让人最头痛的，不是配置多个数据源，而是如何能灵活动态的切换数据源。例如在一个spring和hibernate的框架的项目中，我们在spring配置中往往是配置一个dataSource来连接数据库，然后绑定给sessionFactory，在dao层代码中再指定sessionFactory来进行数据库操作。



正如上图所示，每一块都是指定绑死的，如果是多个数据源，也只能是下图中那种方式。



可看出在Dao层代码中写死了两个SessionFactory，这样日后如果再多一个数据源，还要改代码添加一个SessionFactory，显然这并不符合开闭原则。

那么正确的做法应该是



代码如下：

1. applicationContext.xml

<?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:util="http://www.springframework.org/schema/util"
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-3.0.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd">

<bean name="dataSource" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close">
<property name="url" value="${db.conn.url}" />
<property name="username" value="${db.conn.userName}" />
<property name="password" value="${db.conn.password}" />
<property name="initialSize" value="0" />
<property name="maxActive" value="${db.conn.maxActive}" />
<property name="maxIdle" value="${db.conn.maxIdle}" />
<property name="minIdle" value="0" />
<property name="maxWait" value="${db.conn.maxWait}" />
<!-- <property name="poolPreparedStatements" value="true" /> <property name="maxPoolPreparedStatementPerConnectionSize" value="33" /> -->
<property name="validationQuery" value="${validationQuery}" />
<property name="testOnBorrow" value="false" />
<property name="testOnReturn" value="false" />
<property name="testWhileIdle" value="true" />
<property name="timeBetweenEvictionRunsMillis" value="60000" />
<property name="minEvictableIdleTimeMillis" value="25200000" />
<property name="removeAbandoned" value="true" />
<property name="removeAbandonedTimeout" value="1800" />
<property name="logAbandoned" value="true" />
<!-- <property name="filters" value="stat" /> -->
<property name="filters" value="mergeStat" />
</bean>

<bean name="dataSourcePerson" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close">
<property name="url" value="${person.db.conn.url}" />
<property name="username" value="${person.db.conn.userName}" />
<property name="password" value="${person.db.conn.password}" />
<property name="initialSize" value="0" />
<property name="maxActive" value="${db.conn.maxActive}" />
<property name="maxIdle" value="${db.conn.maxIdle}" />
<property name="minIdle" value="0" />
<property name="maxWait" value="${db.conn.maxWait}" />
<!-- <property name="poolPreparedStatements" value="true" />

<property name="maxPoolPreparedStatementPerConnectionSize" value="33" /> -->
<property name="validationQuery" value="${validationQuery}" />
<property name="testOnBorrow" value="false" />
<property name="testOnReturn" value="false" />
<property name="testWhileIdle" value="true" />
<property name="timeBetweenEvictionRunsMillis" value="60000" />
<property name="minEvictableIdleTimeMillis" value="25200000" />
<property name="removeAbandoned" value="true" />
<property name="removeAbandonedTimeout" value="1800" />
<property name="logAbandoned" value="true" />
<!-- <property name="filters" value="stat" /> -->
<property name="filters" value="mergeStat" />
</bean>

<bean id="multipleDataSource" class="com.hnlat.common.util.MultipleDataSource">
<property name="defaultTargetDataSource" ref="dataSource"/>
<property name="targetDataSources">
<map>
<entry key="dataSource" value-ref="dataSource"/>
<entry key="dataSourcePerson" value-ref="dataSourcePerson"/>
</map>
</property>
</bean>

<bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
<property name="dataSource" ref="multipleDataSource" />
<property name="hibernateProperties">
<props>
<prop key="hibernate.hbm2ddl.auto">${hibernate.hbm2ddl.auto}</prop>
<prop key="hibernate.dialect">${hibernate.dialect}</prop>
<prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
<prop key="hibernate.format_sql">${hibernate.format_sql}</prop>
</props>
</property&g
4000
t;

<property name="packagesToScan">
<list>
<value>com.hnlat.***.domain</value>
</list>
</property>
</bean>

<bean id="transactionManager" class="org.springframework.orm.hibernate5.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory"/>
</bean>

<tx:annotation-driven transaction-manager="transactionManager" />

<tx:advice id="transactionAdvice" transaction-manager="transactionManager">
<tx:attributes>
<tx:method name="add*" />
<tx:method name="save*" />
<tx:method name="update*" />
<tx:method name="modify*" />
<tx:method name="edit*" />
<tx:method name="delete*" />
<tx:method name="remove*" />
<tx:method name="repair" />
<tx:method name="deleteAndRepair" />

<tx:method name="get*" propagation="SUPPORTS" />
<tx:method name="find*" propagation="SUPPORTS" />
<tx:method name="load*" propagation="SUPPORTS" />
<tx:method name="search*" propagation="SUPPORTS" />
<tx:method name="datagrid*" propagation="SUPPORTS" />

<tx:method name="*" propagation="SUPPORTS" />
</tx:attributes>
</tx:advice>

<aop:config>
<aop:pointcut id="transactionPointcut" expression="execution(* com.hnlat.*.service..*Impl.*(..))" />
<aop:advisor pointcut-ref="transactionPointcut" advice-ref="transactionAdvice" />
</aop:config>

</beans>

2.MultipleDataSource.java

这个数据源类 有方法设置数据源的KEY就能切换数据源了

/**
* 多数据源管理
* @author admin
*
*/
@Component
public class MultipleDataSource extends AbstractRoutingDataSource {
private static final ThreadLocal<String> dataSourceKey = new InheritableThreadLocal<String>();

public static void setDataSourceKey(String dataSource) {
dataSourceKey.set(dataSource);
}

@Override
protected Object determineCurrentLookupKey() {
return dataSourceKey.get();
}
}

3.MultipleDataSourceAspectAdvice.java

/**
* 自动切换数据源
*
* @author admin
*
*/
@Component
@Aspect
public class MultipleDataSourceAspectAdvice {

@Around("execution(* com.hnlat.*.service..*Impl.*(..))")
public Object doAround(ProceedingJoinPoint jp) throws Throwable {
// 如果是SSO的server就切换数据源
if (jp.getTarget() instanceof ScholarService) {
MultipleDataSource.setDataSourceKey("dataSourcePerson");
} else {
MultipleDataSource.setDataSourceKey("dataSource");
}
return jp.proceed();
}

}

首先切面把所有的service都抓进来

然后判断根据不同的service 调用不同的 数据源

至此 每次调用不同的service都能切换到相对应的数据库了

所有要去dataSourcePerson数据源查询的都去实现ScholarService这个接口就行了

注:<bean id="multipleDataSource" class="com.hnlat.common.util.MultipleDataSource">
<property name="defaultTargetDataSource" ref="dataSource"/>
<property name="targetDataSources">
<map>
<entry key="dataSource" value-ref="dataSource"/>
<entry key="dataSourcePerson" value-ref="dataSourcePerson"/>
</map>
</property>
</bean>这里在启动的时候是默认dataSource这个数据源，在hibernate使用注解实体与表关系的时候，会去默认的数据源查找表，也就是说如果你要使用hibernate注解dataSourcePerson这个数据源数据库里面的表时，启动是他却会去dataSource里面找表，这样就会启动报错。这很尴尬！我不知道要如何解决这个问题，所以我只好把dataSourcePerson的表在dataSource里面穿件一个空表！

以上是第一种方法，还有第二种方法：

  1. applicationContext.xml<?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:util="http://www.springframework.org/schema/util"
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-3.0.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd">

<bean name="dataSource" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close">
<property name="url" value="${db.conn.url}" />
<property name="username" value="${db.conn.userName}" />
<property name="password" value="${db.conn.password}" />
<property name="initialSize" value="0" />
<property name="maxActive" value="${db.conn.maxActive}" />
<property name="maxIdle" value="${db.conn.maxIdle}" />
<property name="minIdle" value="0" />
<property name="maxWait" value="${db.conn.maxWait}" />
<property name="validationQuery" value="${validationQuery}" />
<property name="testOnBorrow" value="false" />
<property name="testOnReturn" value="false" />
<property name="testWhileIdle" value="true" />
<property name="timeBetweenEvictionRunsMillis" value="60000" />
<property name="minEvictableIdleTimeMillis" value="25200000" />
<property name="removeAbandoned" value="true" />
<property name="removeAbandonedTimeout" value="1800" />
<property name="logAbandoned" value="true" />
<property name="filters" value="mergeStat" />
</bean>

<bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
<property name="dataSource" ref="multipleDataSource" />
<property name="hibernateProperties">
<props>
<prop key="hibernate.hbm2ddl.auto">${hibernate.hbm2ddl.auto}</prop>
<prop key="hibernate.dialect">${hibernate.dialect}</prop>
<prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
<prop key="hibernate.format_sql">${hibernate.format_sql}</prop>
</props>
</property>

<property name="packagesToScan">
<list>
<value>com.hnlat.***.domain</value>
</list>
</property>
</bean>

<bean id="transactionManager" class="org.springframework.orm.hibernate5.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory"/>
</bean>

<tx:annotation-driven transaction-manager="transactionManager" />

<tx:advice id="transactionAdvice" transaction-manager="transactionManager">
<tx:attributes>
<tx:method name="add*" />
<tx:method name="save*" />
<tx:method name="update*" />
<tx:method name="modify*" />
<tx:method name="edit*" />
<tx:method name="delete*" />
<tx:method name="remove*" />
<tx:method name="repair" />
<tx:method name="deleteAndRepair" />
<tx:method name="get*" propagation="SUPPORTS" />
<tx:method name="find*" propagation="SUPPORTS" />
<tx:method name="load*" propagation="SUPPORTS" />
<tx:method name="search*" propagation="SUPPORTS" />
<tx:method name="datagrid*" propagation="SUPPORTS" />
<tx:method name="*" propagation="SUPPORTS" />
</tx:attributes>
</tx:advice>

<bean name="dataSourcePerson" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close">
<property name="url" value="${person.db.conn.url}" />
<property name="username" value="${person.db.conn.userName}" />
<property name="password" value="${person.db.conn.password}" />

<property name="initialSize" value="0" />
<property name="maxActive" value="${db.conn.maxActive}" />
<property name="maxIdle" value="${db.conn.maxIdle}" />
<property name="maxWait" value="${db.conn.maxWait}" />
<property name="validationQuery" value="${validationQuery}" />
<property name="testOnBorrow" value="false" />
<property name="testOnReturn" value="false" />
<property name="testWhileIdle" value="true" />
<property name="timeBetweenEvictionRunsMillis" value="60000" />
<property name="minEvictableIdleTimeMillis" value="25200000" />
<property name="removeAbandoned" value="true" />
<property name="removeAbandonedTimeout" value="1800" />
<property name="logAbandoned" value="true" />
<property name="filters" value="mergeStat" />
</bean>

<bean id="personJdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate" abstract="false"
lazy-init="false" autowire="default" >
<property name="dataSource">
<ref bean="dataSourcePerson" />
</property>
</bean>

<aop:config>
<aop:pointcut id="transactionPointcut" expression="execution(* com.hnlat.*.service..*Impl.*(..))" />
<aop:advisor pointcut-ref="transactionPointcut" advice-ref="transactionAdvice" />
</aop:config>

</beans>

2.personCommJdbcDao.java

@Repository
public class PersonCommJdbcDao{

@Autowired
@Qualifier("personJdbcTemplate")
private JdbcTemplate template;

public List<Map<String, Object>> queryList(String sql,Object...args){
return template.queryForList(sql, args);
}
}

这个使用的是spring的JdbcTemplate方法，使用方法与jdbc类似，具体百度，我也是才了解！他没有集成hibernate！

其他方法还在了解