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。

解决方法如下：

1、首先配置多个datasource

 1 <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">

 2      <property name="driverClassName" value="net.sourceforge.jtds.jdbc.Driver">

 3   </property>

 4   <property name="url" value="jdbc:jtds:sqlserver://10.82.81.51:1433;databaseName=standards">

 5   </property>

 6   <property name="username" value="youguess"></property>

 7   <property name="password" value="youguess"></property>

 8  </bean>

 9  <bean id="dataSource2" class="org.apache.commons.dbcp.BasicDataSource">

10      <property name="driverClassName" value="net.sourceforge.jtds.jdbc.Driver">

11   </property>

12   <property name="url" value="jdbc:jtds:sqlserver://10.82.81.52:1433;databaseName=standards">

13   </property>

14   <property name="username" value="youguess"></property>

15   <property name="password" value="youguess"></property>

16 </bean>

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

 

1 package com.standard.core.util;

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

3 public class DynamicDataSource extends AbstractRoutingDataSource {

4     @Override

5     protected Object determineCurrentLookupKey() {

6         return CustomerContextHolder.getCustomerType();

7     }

8 }

 

3、利用ThreadLocal解决线程安全问题

 

 1 package com.standard.core.util;

 2 public class CustomerContextHolder {

 3     public static final String DATA_SOURCE_A = "dataSource";

 4     public static final String DATA_SOURCE_B = "dataSource2";

 5     private static final ThreadLocal<String> contextHolder = new ThreadLocal<String>();

 6     public static void setCustomerType(String customerType) {

 7         contextHolder.set(customerType);

 8     }

 9     public static String getCustomerType() {

10         return contextHolder.get();

11     }

12     public static void clearCustomerType() {

13         contextHolder.remove();

14     }

15 }

 

 

 

4、数据源配置

 

 

 1 <bean id="dynamicDataSource" class="com.standard.core.util.DynamicDataSource" >

 2         <property name="targetDataSources">

 3             <map key-type="java.lang.String">

 4                 <entry value-ref="dataSource" key="dataSource"></entry>

 5                 <entry value-ref="dataSource2" key="dataSource2"></entry>

 6             </map>

 7         </property>

 8         <property name="defaultTargetDataSource" ref="dataSource" >

 9         </property>

10     </bean> 

5、在DAOImpl中切换数据源

1 CustomerContextHolder.setCustomerType(CustomerContextHolder.DATA_SOURCE_B);