利用Spring的AbstractRoutingDataSource解決多數據源的問題

多數據源問題很常見，例如讀寫分離數據庫配置。

原來的項目出現了新需求，局方要求新增某服務器用以提供某代碼，涉及到多數據源的問題。

解決方法如下：

1、首先配置多個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、寫一個DynamicDataSource類繼承AbstractRoutingDataSource，並實現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解決線程安全問題

 

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、數據源配置

 

 

<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中切換數據源

CustomerContextHolder.setCustomerType(CustomerContextHolder.DATA_SOURCE_B);