⟩ How do I create a producer pool?
The following is some pseudo-code
for a producer class.
class ProducerPool {
static Hashmap pSets = new Hashtable();
static Hashmap inUse = new Hashtable();
QueueSender get(String contextURL,
String connectionFactoryName,
String destinationName) {
String lookup = contextURL+";
"+connectionFactName+";"+destName;
synchronized(pSets) {
producer set = pSets.get(lookup);
if (set != null && set not empty)
qs = set.removeFirst();
}
if (producer == null) {
create ctx
get connect factory
create connection
create session
look up destination
qs = create queue sender
}
synchronized(inUse) {
inUse.put(qs, lookup);
}
return qs;
}
void put(QueueSender qs) {
String lookup;
synchronized(inUse) {
lookup = inUse.remove(p);
}
synchronzied(pSets) {
producer set = pSets.get(lookup);
if (set == null) {
producer set = new producer set
pSets.put(lookup, producer set);
}
producer set.add(qs);
}
}
}
Note: Static classes may be garbage collected if there are no references to them, so make sure the application server has a permanent pointer to them in some manner. One way is to reference it permanently from within a servlet or EJB when they are initialized at startup.
Here is an example of using the producer pool within the onMessage method.
onMessage() {
QueueSender qs = ProducerPool.get(...);
qs.send(...);
ProducerPool.put(qs);
}
You can pre-populate this pool by calling it from
a startup class or a load-on-start servlet class.
