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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);