hibernate not calling setReadOnly(true) on connection

I'm trying to set up my spring / hibernate project to work with master/slave database setup.

Transactions seem to work in spring (for example when I try to hibernateTemplate.merge() within a method annotated as @Transactional(readOnly=true) I get an exception). But hibernate does not use the slave database within methods annotated.

@Transactional(readOnly=true).

<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
      destroy-method="close">
    <property name="driverClassName" value="com.mysql.jdbc.ReplicationDriver"/>
    <property name="url" value="jdbc:mysql:replication://master:3306,slave:3306/proust"/>
    <property name="username" value="username"/>
    <property name="password" value="password"/>
</bean>

<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"开发者_如何学Python>
    <property name="dataSource" ref="dataSource"/>
</bean>

<tx:annotation-driven transaction-manager="transactionManager"/>

Then I annotate the manager class or DAO class with:

@Transactional(readOnly = true)

... and some methods with

@Transactional(readOnly = false)

I expect some methods in the class to be executed against the master, and some against the slave, but they all get executed against the master. What could I be doing wrong?

Hibernate does not switch the JDBC connection to the R/O mode with regard to the @Transactional annotation, it only prevents flushing of changes.