Hi Filip,
basically connections can be kept open as long as you like. They are
also thread safe. For connections there is the problem that they can
become invalid if the server goes away for too long.
Sessions can also be kept open but they are not thread safe. So make
sure you do not share a session between threads.
I suggest that you take a look at the spring jms abstractions. They help
with a lot of the problems you may have.
The keywords you need JmsTemplate, DefaultMessageListenerContainer.
Be careful though. The spring jmstemplate always closes the connection
after a request. So you have to use a pooling connection factory.
Application servers sometimes provide these.
When doing a standalone application you may want to wrap the connection
factory in a spring CachingConnectionFactory.
Frameworks like Camel and CXF use this aproach as it makes life a lot
easier than working with JMS directly.
If your focus is on simply sending and receiving your objects in a
really easy way you might even want to use Apache Camel.
http://camel.apache.org/jms.html
http://camel.apache.org/pojo-messaging-example.html
Messaging can´t be easier than with camel and it embeds nicely in your
application.
Best regards
Christian
Am 04.03.2011 18:07, schrieb Filip Nguyen:
I am using ActiveMQ and I am reading Java Message Service document
which specifies the JMS JSR. However I cant find anywhere what are the
best practices for Connection length. From the JMS JSR I understand that:
Connection is Heavy weight object as JMS JSR suggests. So its ok to
create it at start of the application and release it just before
application closes
Going further the Session is supposed to be lightweight object so
there should be no problem to create it more often. Butas indicated
here:
http://activemq.2283324.n4.nabble.com/receiveNoWait-problem-td2347600.html
there is James.Strachan suggests to use 1 consumer for whole
application to aovid receivenowait problems.
My questions are (assuming I want to avoid requestNoWait problems and
i dont want to call receive(1000)):
1. How long should connection be opened (after calling start()) and
are there
any problems with having it opened for a long long time?
2. How long should one Session be opened? (this relates to
MessageConsumer
because I assume the consumer needs to have session opened).
Filip Nguyen
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