spring - Choose between muliple transaction managers at runtime -

i have 2 clients using same spring based rest application deployed in tomcat. depending on client need choose between data sources , transaction manager. how choose @ runtime, transaction manager use?

    <bean id="first_datasource" class="org.apache.commons.dbcp.basicdatasource"             destroy-method="close">             <property name="url" value="${first_jdbc.url}" />             <property name="driverclassname" value="${first_jdbc.driverclassname}" />             <property name="username" value="${first_jdbc.username}" />             <property name="password" value="${first_jdbc.password}" />             <property name="removeabandoned" value="true" />             <property name="initialsize" value="20" />             <property name="maxactive" value="30" />             <!-- <property name="defaultautocommit" value="false" /> -->    </bean>      <bean id="second_datasource" class="org.apache.commons.dbcp.basicdatasource"             destroy-method="close">             <property name="url" value="${second_jdbc.url}" />             <property name="driverclassname" value="${second_jdbc.driverclassname}" />             <property name="username" value="${second_jdbc.username}" />             <property name="password" value="${second_jdbc.password}" />             <property name="removeabandoned" value="true" />             <property name="initialsize" value="20" />             <property name="maxactive" value="30" />             <!-- <property name="defaultautocommit" value="false" /> -->    </bean>  <bean id="first_transactionmanager"     class="org.springframework.jdbc.datasource.datasourcetransactionmanager"         scope="singleton">         <property name="datasource" ref="first_datasource" />         <qualifier value="sc_tm"></qualifier> </bean>  <bean id="second_transactionmanager"           class="org.springframework.jdbc.datasource.datasourcetransactionmanager"           scope="singleton">           <property name="datasource" ref="second_datasource" />           <qualifier value="second_tm"></qualifier> </bean>    

in code how choose @transactional("????") @ run time. if not possible org.springframework.jdbc.datasource.datasourcetransactionmanager there other way of doing it?

using @transactional, can specify transaction manager this:

@transactional("first_transactionmanager") 

or

@transactional("second_transactionmanager") 

depending on 1 want use. make sure use inside transactional method correct entity manager / session factory. have specify 1 want inject @persistencecontext("nameofpersistenceunit").