OpenEdge Development:<br />Messaging and ESB Publishing, receiving, and processing a StreamMessage

Connect to the Sportsdatabase.

Run example9.p (1 of 2) to receive the StreamMessage containing the customer names and numbers, as shown:

example9.p
/* Receives a Stream message. / DEFINE VARIABLE pubsubsession AS HANDLE. DEFINE VARIABLE consumerH AS HANDLE. / Creates a session object. / RUN jms/pubsubsession.p PERSISTENT SET pubsubsession ("-H localhost -S 5162 "). RUN setBrokerURL IN pubsubsession ("localhost:2506"). RUN beginSession IN pubsubsession. / Subscribe to the newCustomers topic. The newCustHandler internal procedure handles the list of new customers. / RUN createMessageConsumer IN pubsubsession ( THIS-PROCEDURE, / This proc will handle it / "newCustHandler", / name of internal procedure / OUTPUT consumerH). RUN subscribe IN pubsubsession ( "NewCustomers", / name of topic / ?, / Subscription is not durable/ ?, / No message selector. / no, / Want my own messages too / consumerH). / handles the messages / / Start receiving messages / RUN startReceiveMessages IN pubsubsession. / Wait to receive the messages. Any other IO-blocked statements can be used for receiving messages. */ WAIT-FOR u1 OF THIS-PROCEDURE.
PROCEDURE newCustHandler: DEFINE INPUT PARAMETER messageH AS HANDLE. DEFINE INPUT PARAMETER msgConsumerH AS HANDLE. DEFINE OUTPUT PARAMETER replyH AS HANDLE. /* Display the stream of customer names and customer numbers. / / The moveToNext function moves the cursor to the next item in / / the stream and returns the data type of that item. / / We assume the reply is not required. / IF NOT DYNAMIC-FUNCTION('getMessageType':U IN messageH) = "StreamMessage" THEN RETURN. / Note that the 'moveToNext' functions returns the item's data type. / DO WHILE NOT DYNAMIC-FUNCTION('endOfStream':U IN messageH) WITH DOWN: DISPLAY DYNAMIC-FUNCTION('moveToNext':U IN messageH) DYNAMIC-FUNCTION('readChar':U IN messageH) DYNAMIC-FUNCTION('moveToNext':U IN messageH) DYNAMIC-FUNCTION('readInt':U IN messageH). DOWN. END. RUN deleteMessage IN messageH. APPLY "U1" TO THIS-PROCEDURE. END. / newCustHandler */

example9.p

/* Receives a Stream message. */ 
DEFINE VARIABLE pubsubsession AS HANDLE. 
DEFINE VARIABLE consumerH AS HANDLE. 
/* Creates a session object. */ 
RUN jms/pubsubsession.p PERSISTENT SET pubsubsession  
                                  ("-H localhost -S 5162 "). 
RUN setBrokerURL IN pubsubsession ("localhost:2506"). 
RUN beginSession IN pubsubsession. 
/* Subscribe to the newCustomers topic. The newCustHandler internal
   procedure handles the list of new customers. 
*/ 
RUN createMessageConsumer IN pubsubsession ( 
                    THIS-PROCEDURE,    /* This proc will handle it */ 
                    "newCustHandler",  /* name of internal procedure */ 
                    OUTPUT consumerH). 
RUN subscribe IN pubsubsession (
                      "NewCustomers", /* name of topic */ 
                      ?,              /* Subscription is not durable*/ 
                      ?,              /* No message selector. */ 
                      no,             /* Want my own messages too */ 
                      consumerH).     /* handles the messages */ 
/* Start receiving messages */ 
RUN startReceiveMessages IN pubsubsession. 
/* Wait to receive the messages. Any other IO-blocked statements can be
   used for receiving messages.
*/ 
WAIT-FOR u1 OF THIS-PROCEDURE.

PROCEDURE newCustHandler: 
DEFINE INPUT PARAMETER messageH AS HANDLE. 
DEFINE INPUT PARAMETER msgConsumerH AS HANDLE. 
DEFINE OUTPUT PARAMETER replyH AS HANDLE. 
 /* Display the stream of customer names and customer numbers. */ 
 /* The moveToNext function moves the cursor to the next item in */ 
 /* the stream and returns the data type of that item.          */ 
 /* We assume the reply is not required. */ 
 IF NOT  DYNAMIC-FUNCTION('getMessageType':U IN messageH) = 
                                                 "StreamMessage" 
      THEN RETURN. 
 /* Note that the 'moveToNext' functions returns the item's data type. */ 
 DO WHILE NOT  DYNAMIC-FUNCTION('endOfStream':U IN messageH) WITH DOWN: 
    DISPLAY DYNAMIC-FUNCTION('moveToNext':U IN messageH)   
            DYNAMIC-FUNCTION('readChar':U IN messageH)  
            DYNAMIC-FUNCTION('moveToNext':U IN messageH)   
            DYNAMIC-FUNCTION('readInt':U IN messageH). 
    DOWN. 
 END. 
 RUN deleteMessage IN messageH. 
 APPLY "U1" TO THIS-PROCEDURE. 
END. /* newCustHandler */

Run example8.p to publish a StreamMessage containing customer names and numbers, as shown:

example8.p
/* Publishing a Stream message. / DEFINE VARIABLE pubsubsession AS HANDLE. DEFINE VARIABLE messageH AS HANDLE. / Creates a session object. / RUN jms/pubsubsession.p PERSISTENT SET pubsubsession ("-H localhost -S 5162 "). RUN setBrokerURL IN pubsubsession ("localhost:2506"). RUN beginSession IN pubsubsession. / Create a stream message / RUN createStreamMessage IN pubsubsession (OUTPUT messageH). / Load the message with a list of customer names and cust-nums. / FOR EACH customer: RUN writeString IN messageH (customer.name). RUN writeInt IN messageH (customer.cust-num). END. / Publish the message on the NewCustomers topic. */ RUN publish IN pubsubsession ("NewCustomers", messageH, ?, ?, ?).

example8.p

/* Publishing a Stream message. */ 
DEFINE VARIABLE pubsubsession AS HANDLE. 
DEFINE VARIABLE messageH AS HANDLE. 
/* Creates a session object. */ 
RUN jms/pubsubsession.p PERSISTENT SET pubsubsession  
                                  ("-H localhost -S 5162 "). 
RUN setBrokerURL IN pubsubsession ("localhost:2506"). 
RUN beginSession IN pubsubsession. 
/* Create a stream message */ 
RUN createStreamMessage IN pubsubsession (OUTPUT messageH). 
/* Load the message with a list of customer names and cust-nums. */ 
FOR EACH customer: 
   RUN writeString IN messageH (customer.name). 
   RUN writeInt IN messageH (customer.cust-num). 
END. 
/* Publish the message on the NewCustomers topic. */ 
RUN publish IN pubsubsession ("NewCustomers", messageH, ?, ?, ?).