Camel ProducerTemplate versus Spring JMSTemplate

Question

I am using camel to send message to an IBM MQQueue. The MDB listening to this queue expects messages of the type com.ibm.jms.JMSMapMessage.

When I use camel producerTemplate, an exception is thrown. I am doing this producerTemplate.sendBody("wmq:queue",hashMap);

Exception data: java.lang.ClassCastException: com.ibm.jms.JMSMapMessage incompatible with javax.jms.ObjectMessage

So I tried Spring jmsTemplate, and it worked.

jmsTemplate.send(new MessageCreator() {
            @Override
            public Message createMessage(Session session)
                    throws JMSException {
                return session.createObjectMessage((Serializable) sctHmap);
            }
        });

Question: The jms component documentation says

It uses Spring's JMS support for declarative transactions, including Spring's JmsTemplate for sending and a MessageListenerContainer for consuming.

I tried with disabling camels auto conversion using mapJmsMessage=false. I realised it would not help as it would have sent a hash map, I still got the same exception. Is there any way I can get the producerTemplate to work in the same way as JMSTemplate? ProducerTemplate seems to be more elegant, atleast in terms of my unit tests

just serialize your hashmap to json and then send it as body. It can then be converted to any type — pvpkiran
What version of Camel do you use? And you can try setting ?jmsMessageType=Map as paramter to the endpoint uri in the camel producer template. — Claus Ibsen
And just to be sure the hashMap instance you send as the message body is a java.util.Map instance? — Claus Ibsen
i am using 2.20.1, i explicitly set the jmsMessagetype=Map, first as an option and second in the header. To do the latter I created a route, from("direct:start").setHeader().to(wmq) and used the producerTemplate to sendBody to this route — pointerness

pointerness pointerness · Accepted Answer · 2018-02-14T06:38:00

It seems I misinterpreted the classcast exception message. Camel was correctly sending, com.ibm.jms.JMSMapMessage, the MDB at the consumer application was expecting javax.jms.ObjectMessage. I resolved it by setting jmsMessageType=object in the endpoint URI. :)

Camel ProducerTemplate versus Spring JMSTemplate

1 Answers