Using HashMaps in an EJB

Question

Ok this is the second time Im posting this problem. Last time I posted all the details and it may have been more general. This time I will be more specific. The following are the requirement that we were given for a school assignment,
Develop a prototype software module to implement a messenger service. Messaging
Systems consist of one Messaging server and several clients. Message can differ from a simple text message to a complex object like an Image. System should include following components.
� Messaging Server: A Messaging server will hold the message queue for our
Messaging system (which you need to develop)
� Messaging Queue: A Queue will hold the messages from the client. The
messages on this queue will be MapMessages that will allow us to store
name/value pair information about the message to be sent out
� Message Client: A client will create a message, and put it on the Messaging
Queue. This message will hold the information for the email message to be sent out
� Message Driven Bean: A message driven bean will be responsible for taking in the Message MapMessage and for mailing it out.
To develop the system you have to use EJB 3.0 architecture. Usage of Java Persistence
API for modeling data would be recommended.
I dont want the coding to develop the system, I have already created that part and it works perfectly when I send text or numbers as messages. What I need help is on how to handle a hashMap. Simply SET'ing and GET'ing a hashMap does not seem to work. If you good people can give me some pointers on how to set up the entity and how the GET'ing and SET'ing methods work in relation to the HashMap I would be a very happy and thankful guy indeed.
P.S - The *** indicate 'ing. The forum seems to sensor those words.
Message was edited by:
jomanlk

Answer 1

WELL I gone through your code in the link
http://forum.java.sun.com/thread.jspa?threadID=5138929&messageID=9509475#9509475
Well thats the important parts of the code. it works fine when I send >simple messages but when I try out the HashMap the servlet is >displayed but no messages are sent to the queue. It would be great if >anyone could help. The reason is simple;
THE HASHMAP CONTAIN NULL VALUES AND YOU ARE SENDING NULL TO THE JMS SO NO OUTPUT.
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
String title=request.getParameter("title");
     System.out.println("TITLE IS     :"+title);
String body=request.getParameter("body");
     System.out.println("BODY IS     :"+body);
HashMap hm = new HashMap();
//hm.put("title", request.getParameter("title"));
//hm.put("body", request.getParameter("body"));
     hm.put("title",title );
hm.put("body", body);
if ((title!=null) && (body!=null)) {
try {
Connection connection = connectionFactory.createConnection();
Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
MessageProducer messageProducer = session.createProducer(queue);
ObjectMessage message = session.createObjectMessage();
// here we create NewsEntity, that will be sent in JMS message
NewsEntity e = new NewsEntity();
e.setTitle(title);
e.setBody(body);
e.setHm(hm);
message.setObject(e);
messageProducer.send(message);
messageProducer.close();
connection.close();
// response.sendRedirect("ListNews");
} catch (JMSException ex) {
ex.printStackTrace();
try out this code this modified code and allot some dukes if you succeed best of luck :))