OpenMQ 4.4 b05 nullpointerexception in StompSubscriberSession.onMessage

Question

Hello,
in a test for automatic acknowledge mode, I send a number of messages to the broker and then consume then in two steps, unsubscribing and closing the connection in between.
Sometimes, the server log contains this exception. Maybe it is related to a socket problem (the client closed the socket so the server was not able to send the message)?
INFO: Started JMS connection 1152957546066812160[in] for user admin
21.04.2009 09:23:00
WARNUNG: Unable to deliver message to subscription[{94EED5D7-E09D-4407-A3C9-244D
F197AFEE}]: null
java.lang.NullPointerException
at com.sun.messaging.bridge.service.stomp.StompSubscriberSession.onMessa
ge(StompSubscriberSession.java:110)
at com.sun.messaging.jmq.jmsclient.MessageConsumerImpl.deliverAndAcknowl
edge(MessageConsumerImpl.java:338)
at com.sun.messaging.jmq.jmsclient.MessageConsumerImpl.onMessageToListen
erFromReceiveQueue(MessageConsumerImpl.java:316)
at com.sun.messaging.jmq.jmsclient.SessionReader.onMessageToLateListener
s(SessionReader.java:171)
at com.sun.messaging.jmq.jmsclient.SessionReader.deliver(SessionReader.j
ava:149)
at com.sun.messaging.jmq.jmsclient.ConsumerReader.run(ConsumerReader.jav
a:190)
at java.lang.Thread.run(Unknown Source)
21.04.2009 09:23:00
WARNUNG: Unable to send error message: null
java.lang.NullPointerException
at com.sun.messaging.bridge.service.stomp.StompSubscriberSession.onMessa
ge(StompSubscriberSession.java:134)
at com.sun.messaging.jmq.jmsclient.MessageConsumerImpl.deliverAndAcknowl
edge(MessageConsumerImpl.java:338)
at com.sun.messaging.jmq.jmsclient.MessageConsumerImpl.onMessageToListen
erFromReceiveQueue(MessageConsumerImpl.java:316)
at com.sun.messaging.jmq.jmsclient.SessionReader.onMessageToLateListener
s(SessionReader.java:171)
at com.sun.messaging.jmq.jmsclient.SessionReader.deliver(SessionReader.j
ava:149)
at com.sun.messaging.jmq.jmsclient.ConsumerReader.run(ConsumerReader.jav
a:190)
at java.lang.Thread.run(Unknown Source)
21.04.2009 09:23:00
INFO: Stomp connection 1152957546066812160[in] closed.
21.04.2009 09:23:01

Answer 1

This is the (Delphi) code which I am currently testing. The nullpointerexception does not occur in every test run, maybe one out of five.
The test however is also the only one which fails, because the second read does not get all remaining messages everytime. (There should be 10 messages still in the queue). I will try to investigate it further.
Mike
procedure TSendReceiveTests.TestAutoAck;
const
NUM_MSG = 10;
var
Consumer: IMessageConsumer;
Producer: IMessageProducer;
Msg: IMessage;
I: Integer;
begin
Consumer := Session.CreateConsumer(Queue);
// Drain any messages that may allready be in the sub
while Assigned(Consumer.Receive(1000)) do;
Consumer.Close;
Connection.Close;
// send 20 messages
Producer := OutSession.CreateProducer(OutQueue);
// Producer.TimeToLive := 50000;
for I := 1 to 2 * NUM_MSG do
begin
Msg := OutSession.CreateTextMessage;
Msg.JMSCorrelationID := IntToStr(I);
WriteLn('Send ID: ' + Msg.JMSCorrelationID);
Producer.Send(Msg);
end;
OutConnection.Close;
// reopen conn and read 10 messages
CreateInConnection;
Consumer := Session.CreateConsumer(Queue);
for I := 1 to NUM_MSG do
begin
Msg := Consumer.Receive(2000);
if not Assigned(Msg) then
Fail('Received no message (1) ' + IntToStr(I))
else
WriteLn('Receive ID: ' + Msg.JMSCorrelationID);
end;
Consumer.Close;
Connection.Close;
// reopen conn and read 10 messages
CreateInConnection;
Consumer := Session.CreateConsumer(Queue);
for I := 1 to NUM_MSG do
begin
Msg := Consumer.Receive(2000);
if not Assigned(Msg) then
Fail('Received no message (2) ' + IntToStr(I))
else
WriteLn(IntToStr(I) + ' Receive ID: ' + Msg.JMSCorrelationID);
end;
Consumer.Close;
Connection.Close;
end;