SpringMvc 多數據源實現配置

1.繼承AbstractRoutingDataSource。重寫數據源切換方法

public class DynamicDataSource extends AbstractRoutingDataSource {
    @Override
    protected Object determineCurrentLookupKey() {
        // 從自定義的位置獲取數據源標識
        return DynamicDataSourceHolder.getDataSource();
    }
}

public class DynamicDataSourceHolder {
    /**
     * 注意：數據源標識保存在線程變量中，避免多線程操做數據源時互相干擾
     */
    private static final ThreadLocal<String> THREAD_DATA_SOURCE = new ThreadLocal<String>();

    public static String getDataSource() {
        return THREAD_DATA_SOURCE.get();
    }

    public static void setDataSource(String dataSource) {
        THREAD_DATA_SOURCE.set(dataSource);
    }

    public static void clearDataSource() {
        THREAD_DATA_SOURCE.remove();
    }

}

2.編寫SPRING 配置文件（ApplicationContext.xml）

<bean id="dataSource1" class="com.alibaba.druid.pool.DruidDataSource" destroy-method="close">
     <!-- 數據庫基本信息配置 -->
     <property name="url" value="${url}" />  
     <property name="username" value="${username}" />  
     <property name="password" value="${password}" />  
     <property name="driverClassName" value="${driverClassName}" />  
     <property name="filters" value="${filters}" />  
   	 <!-- 最大併發鏈接數 -->
     <property name="maxActive" value="${maxActive}" />
     <!-- 初始化鏈接數量 -->
     <property name="initialSize" value="${initialSize}" />
     <!-- 配置獲取鏈接等待超時的時間 -->
     <property name="maxWait" value="${maxWait}" />
     <!-- 最小空閒鏈接數 -->
     <property name="minIdle" value="${minIdle}" />  
   	 <!-- 配置間隔多久才進行一次檢測，檢測須要關閉的空閒鏈接，單位是毫秒 -->
     <property name="timeBetweenEvictionRunsMillis" value="${timeBetweenEvictionRunsMillis}" />
     <!-- 配置一個鏈接在池中最小生存的時間，單位是毫秒 -->
     <property name="minEvictableIdleTimeMillis" value="${minEvictableIdleTimeMillis}" />  
     <property name="validationQuery" value="${validationQuery}" />  
     <property name="testWhileIdle" value="${testWhileIdle}" />  
     <property name="testOnBorrow" value="${testOnBorrow}" />  
     <property name="testOnReturn" value="${testOnReturn}" />  
     <property name="maxOpenPreparedStatements" value="${maxOpenPreparedStatements}" />
     <!-- 打開removeAbandoned功能 -->
     <property name="removeAbandoned" value="${removeAbandoned}" />
     <!-- 1800秒，也就是30分鐘 -->
     <property name="removeAbandonedTimeout" value="${removeAbandonedTimeout}" />
     <!-- 關閉abanded鏈接時輸出錯誤日誌 -->   
     <property name="logAbandoned" value="${logAbandoned}" />
</bean>

<bean id="dataSource2" class="com.alibaba.druid.pool.DruidDataSource" destroy-method="close">
	<!-- 數據庫基本信息配置 -->
	<property name="url" value="${url2}" />
	<property name="username" value="${username2}" />
	<property name="password" value="${password2}" />
	<property name="driverClassName" value="${driverClassName2}" />
	<property name="filters" value="${filters}" />
	<!-- 最大併發鏈接數 -->
	<property name="maxActive" value="${maxActive}" />
	<!-- 初始化鏈接數量 -->
	<property name="initialSize" value="${initialSize}" />
	<!-- 配置獲取鏈接等待超時的時間 -->
	<property name="maxWait" value="${maxWait}" />
	<!-- 最小空閒鏈接數 -->
	<property name="minIdle" value="${minIdle}" />
	<!-- 配置間隔多久才進行一次檢測，檢測須要關閉的空閒鏈接，單位是毫秒 -->
	<property name="timeBetweenEvictionRunsMillis" value="${timeBetweenEvictionRunsMillis}" />
	<!-- 配置一個鏈接在池中最小生存的時間，單位是毫秒 -->
	<property name="minEvictableIdleTimeMillis" value="${minEvictableIdleTimeMillis}" />
	<property name="validationQuery" value="${validationQuery}" />
	<property name="testWhileIdle" value="${testWhileIdle}" />
	<property name="testOnBorrow" value="${testOnBorrow}" />
	<property name="testOnReturn" value="${testOnReturn}" />
	<property name="maxOpenPreparedStatements" value="${maxOpenPreparedStatements}" />
	<!-- 打開removeAbandoned功能 -->
	<property name="removeAbandoned" value="${removeAbandoned}" />
	<!-- 1800秒，也就是30分鐘 -->
	<property name="removeAbandonedTimeout" value="${removeAbandonedTimeout}" />
	<!-- 關閉abanded鏈接時輸出錯誤日誌 -->
	<property name="logAbandoned" value="${logAbandoned}" />
</bean>

3.注入dataSoure

<bean id="dataSource" class="com.ucap.sys.dao.DynamicDataSource">
	<property name="targetDataSources">
		<map key-type="java.lang.String">
			<!-- 指定lookupKey和與之對應的數據源 -->
			<entry key="dataSource" value-ref="dataSource1"></entry>
			<entry key="dataSource2" value-ref="dataSource2"></entry>
		</map>
	</property>
	<!-- 這裏能夠指定默認的數據源 -->
	<property name="defaultTargetDataSource" ref="dataSource1" />
</bean>
    
<!-- 配置mybatis -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
	<property name="dataSource" ref="dataSource" />
    <property name="configLocation" value="classpath:mybatis/mybatis-config.xml"></property>
    <!-- mapper掃描 -->
    <property name="mapperLocations" value="classpath:mybatis/*/*.xml"></property>
</bean>

...

4.編寫數據庫配置文件（dbconfig.properties）

driverClassName:oracle.jdbc.driver.OracleDriver
url1:jdbc:oracle:thin:@localhost:1521:ORCL
username:test
password:test

driverClassName2:oracle.jdbc.driver.OracleDriver
url2:jdbc:oracle:thin:@localhost:1521:ORCL
username2:test1
password2:test1

5.切換數據源

public String testChangeDataSource() throws Exception {
    DynamicDataSourceHolder.setDataSource("dataSource2");//設置數據源
    List<PageData> resultList = (List<PageData>) this.dao.findForList("TestDataSourceMapper.findById",new PageData());
    JSONArray array = new JSONArray();
    array.addAll(resultList);
    return array.toJSONString();
}