Topic existence for a specific time

Hi everybody,

Sorry in advance, if it is a very trivial problem. I am rather new to
ActiveMQ.

What I would like to have a topic which will store the messages for a
specific time period e.g half an hour. Any new subscriber should obtain
the messages that were stored since the initialization of the topic. And
the end of half an hour, I would like to close the topic and delete the
previous messages.

It seems a basic problem but if you point me to the related
documentation or examples, I would be very glad.

Thanks,
Suat