利用Spring的AbstractRoutingDataSource解决多数据源的问题(一)

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

<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;

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;

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

<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); 

 

 

For more details,please refer