利用Spring的AbstractRoutingDataSource解决多数据源的问题

 

多数据源问题很常见，例如读写分离数据库配置。

 

原来的项目出现了新需求，局方要求新增某服务器用以提供某代码，涉及到多数据源的问题。

 

研究成果如下：

 

1、首先配置多个datasource

 

 

 

<beanid="dataSource"class="org.apache.commons.dbcp.BasicDataSource">
 <propertyname="driverClassName"value="net.sourceforge.jtds.jdbc.Driver">
 </property>
 <propertyname="url"value="jdbc:jtds:sqlserver://10.82.81.51:1433;databaseName=standards">
 </property>
 <propertyname="username"value="youguess"></property>
 <propertyname="password"value="youguess"></property>
 </bean>
 <beanid="dataSource2"class="org.apache.commons.dbcp.BasicDataSource">
 <propertyname="driverClassName"value="net.sourceforge.jtds.jdbc.Driver">
 </property>
 <propertyname="url"value="jdbc:jtds:sqlserver://10.82.81.52:1433;databaseName=standards">
 </property>
 <propertyname="username"value="youguess"></property>
 <propertyname="password"value="youguess"></property>
</bean>

 

<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
	    <property name="driverClassName" value="net.sourceforge.jtds.jdbc.Driver">
		</property>
		<property name="url" value="jdbc:jtds:sqlserver://10.82.81.51:1433;databaseName=standards">
		</property>
		<property name="username" value="youguess"></property>
		<property name="password" value="youguess"></property>
	</bean>
	<bean id="dataSource2" class="org.apache.commons.dbcp.BasicDataSource">
	    <property name="driverClassName" value="net.sourceforge.jtds.jdbc.Driver">
		</property>
		<property name="url" value="jdbc:jtds:sqlserver://10.82.81.52:1433;databaseName=standards">
		</property>
		<property name="username" value="youguess"></property>
		<property name="password" value="youguess"></property>
</bean>

 

 

 

 

 

2、写一个DynamicDataSource类继承AbstractRoutingDataSource，并实现determineCurrentLookupKey方法

 

 

 

package com.standard.core.util;
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
publicclass DynamicDataSource extends AbstractRoutingDataSource {
 @Override
 protected Object determineCurrentLookupKey() {
 return CustomerContextHolder.getCustomerType();
 }
}

 

package com.standard.core.util;
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
public class DynamicDataSource extends AbstractRoutingDataSource {
	@Override
	protected Object determineCurrentLookupKey() {
		return CustomerContextHolder.getCustomerType();
	}
}

 

 

 

 

 

 

 

3、利用ThreadLocal解决线程安全问题

 

 

 

package com.standard.core.util;
publicclass CustomerContextHolder {
 publicstaticfinal String DATA_SOURCE_A = "dataSource";
 publicstaticfinal String DATA_SOURCE_B = "dataSource2";
 privatestaticfinal ThreadLocal<String> contextHolder = new ThreadLocal<String>();
 publicstaticvoid setCustomerType(String customerType) {
 contextHolder.set(customerType);
 }
 publicstatic String getCustomerType() {
 return contextHolder.get();
 }
 publicstaticvoid clearCustomerType() {
 contextHolder.remove();
 }
}

 

package com.standard.core.util;
public class CustomerContextHolder {
	public static final String DATA_SOURCE_A = "dataSource";
	public static final String DATA_SOURCE_B = "dataSource2";
	private static final ThreadLocal<String> contextHolder = new ThreadLocal<String>();
	public static void setCustomerType(String customerType) {
		contextHolder.set(customerType);
	}
	public static String getCustomerType() {
		return contextHolder.get();
	}
	public static void clearCustomerType() {
		contextHolder.remove();
	}
}

 

4、数据源配置

 

 

 

 

 

<beanid="dynamicDataSource"class="com.standard.core.util.DynamicDataSource">
 <propertyname="targetDataSources">
 <mapkey-type="java.lang.String">
 <entryvalue-ref="dataSource"key="dataSource"></entry>
 <entryvalue-ref="dataSource2"key="dataSource2"></entry>
 </map>
 </property>
 <propertyname="defaultTargetDataSource"ref="dataSource">
 </property>
 </bean>

 

<bean id="dynamicDataSource" class="com.standard.core.util.DynamicDataSource" >
		<property name="targetDataSources">
			<map key-type="java.lang.String">
				<entry value-ref="dataSource" key="dataSource"></entry>
				<entry value-ref="dataSource2" key="dataSource2"></entry>
			</map>
		</property>
		<property name="defaultTargetDataSource" ref="dataSource" >
		</property>
	</bean> 

 

5、在DAOImpl中切换数据源

 

 

 

 

 

CustomerContextHolder.setCustomerType(CustomerContextHolder.DATA_SOURCE_B);

 

CustomerContextHolder.setCustomerType(CustomerContextHolder.DATA_SOURCE_B); 

 

搞定！

 

 

原文：http://blog.csdn.net/alaahong/article/details/8707915