Java Message Service Examples - The Java EE 6 Tutorial: Advanced Topics - page 401

5. Now run the Producer example using a topic instead of a queue.
a. Right-click the producer project and select Properties.
b. Select Run from the Categories tree.
c. In the Arguments field, type the following:
topic 3
d. Click OK.
e. Right-click the project and select Run.
The output looks like this (along with some additional output):
Click here to view code image
Destination type is topic
Sending message: This is message 1 from producer
Sending message: This is message 2 from producer
Sending message: This is message 3 from producer
6. Now run the SynchConsumer example using the topic.
a. Right-click the synchconsumer project and select Properties.
b. Select Run from the Categories tree.
c. In the Arguments field, type the following:
topic
d. Click OK.
e. Right-click the project and select Run.
The result, however, is different. Because you are using a topic, messages that
were sent before you started the consumer cannot be received. (See “ Publish/
Subscribe Messaging Domain ” on page 347 for details.) Instead of receiving
the messages, the program appears to hang.
7. Run the Producer example again. Right-click the producer project and
select Run.
Now the SynchConsumer example receives the messages:
Click here to view code image
Destination type is topic
Reading message: This is message 1 from producer