SpringMvc 多数据源实现配置

1.继承AbstractRoutingDataSource。重写数据源切换方法

public class DynamicDataSource extends AbstractRoutingDataSource {
    @Override
    protected Object determineCurrentLookupKey() {
        // 从自定义的位置获取数据源标识
        return DynamicDataSourceHolder.getDataSource();
    }
}

public class DynamicDataSourceHolder {
    /**
     * 注意：数据源标识保存在线程变量中，避免多线程操做数据源时互相干扰
     */
    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.编写SPRING 配置文件（ApplicationContext.xml）

<bean id="dataSource1" class="com.alibaba.druid.pool.DruidDataSource" destroy-method="close">
     <!-- 数据库基本信息配置 -->
     <property name="url" value="${url}" />  
     <property name="username" value="${username}" />  
     <property name="password" value="${password}" />  
     <property name="driverClassName" value="${driverClassName}" />  
     <property name="filters" value="${filters}" />  
   	 <!-- 最大并发链接数 -->
     <property name="maxActive" value="${maxActive}" />
     <!-- 初始化链接数量 -->
     <property name="initialSize" value="${initialSize}" />
     <!-- 配置获取链接等待超时的时间 -->
     <property name="maxWait" value="${maxWait}" />
     <!-- 最小空闲链接数 -->
     <property name="minIdle" value="${minIdle}" />  
   	 <!-- 配置间隔多久才进行一次检测，检测须要关闭的空闲链接，单位是毫秒 -->
     <property name="timeBetweenEvictionRunsMillis" value="${timeBetweenEvictionRunsMillis}" />
     <!-- 配置一个链接在池中最小生存的时间，单位是毫秒 -->
     <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}" />
     <!-- 打开removeAbandoned功能 -->
     <property name="removeAbandoned" value="${removeAbandoned}" />
     <!-- 1800秒，也就是30分钟 -->
     <property name="removeAbandonedTimeout" value="${removeAbandonedTimeout}" />
     <!-- 关闭abanded链接时输出错误日志 -->   
     <property name="logAbandoned" value="${logAbandoned}" />
</bean>

<bean id="dataSource2" class="com.alibaba.druid.pool.DruidDataSource" destroy-method="close">
	<!-- 数据库基本信息配置 -->
	<property name="url" value="${url2}" />
	<property name="username" value="${username2}" />
	<property name="password" value="${password2}" />
	<property name="driverClassName" value="${driverClassName2}" />
	<property name="filters" value="${filters}" />
	<!-- 最大并发链接数 -->
	<property name="maxActive" value="${maxActive}" />
	<!-- 初始化链接数量 -->
	<property name="initialSize" value="${initialSize}" />
	<!-- 配置获取链接等待超时的时间 -->
	<property name="maxWait" value="${maxWait}" />
	<!-- 最小空闲链接数 -->
	<property name="minIdle" value="${minIdle}" />
	<!-- 配置间隔多久才进行一次检测，检测须要关闭的空闲链接，单位是毫秒 -->
	<property name="timeBetweenEvictionRunsMillis" value="${timeBetweenEvictionRunsMillis}" />
	<!-- 配置一个链接在池中最小生存的时间，单位是毫秒 -->
	<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}" />
	<!-- 打开removeAbandoned功能 -->
	<property name="removeAbandoned" value="${removeAbandoned}" />
	<!-- 1800秒，也就是30分钟 -->
	<property name="removeAbandonedTimeout" value="${removeAbandonedTimeout}" />
	<!-- 关闭abanded链接时输出错误日志 -->
	<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和与之对应的数据源 -->
			<entry key="dataSource" value-ref="dataSource1"></entry>
			<entry key="dataSource2" value-ref="dataSource2"></entry>
		</map>
	</property>
	<!-- 这里能够指定默认的数据源 -->
	<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扫描 -->
    <property name="mapperLocations" value="classpath:mybatis/*/*.xml"></property>
</bean>

...

4.编写数据库配置文件（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.切换数据源

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();
}