JMS ObjectMessage

Question

I successfully sent a JMS message using ObjectMessage. But when receiving, it halts at the point where I tried to get the Object out of the message.....
Source
=============
public void onMessage(Message message)
System.out.println("Message Received");
if(message instanceof ObjectMessage)
System.out.println("Message Type: ObjectMessage");
try{
System.out.println("1");
ISCLPDocument _oISCLPDocument = (ISCLPDocument)((ObjectMessage)message).getObject();<-- stops here or "hangs"
System.out.println("got ISCLPDocument Object");
System.out.println("Message Type = " + _oISCLPDocument.getMessageType());
}catch(Exception _oException)
System.out.println("4");
_oException.printStackTrace();
}

Answer 1

This was most likely caused by the fact that the message consumer had trouble de-serializing the content of the ObjectMessage. You need to make sure that: 1. the object contained in the ObjectMessage as well as all fields of this object are Serializable; 2. Each field of the object contained in the ObjectMessage was set to a value with the EXACTLY matching data type. Let me explain 2.
I this something like this in my code:
SerializableObjectToSend.lastUpdate = someObject.lastUpdate;
where SerializableObjectToSend.lastUpdate was declared as java.util.Date, and someObject.lastUpdate was declared as java.sql.TimeStamp. This compiled fine because TimeStamp is a sub-class of Date. But during run time, the message consumer hung on the getObject() call. Reason: I was pretty sure that it had trouble de-serializing a java.sql.TimeStamp into a java.util.Date !! So I made the following change and everything worked fine:
SerializableObjectToSend.lastUpdate = new java.util.Date(someObject.lastUpdate.getTime());
Hope that helps.