Advanced Queuing - Oracle

JMS Message Consumer Features
NEXT_TRANSACTION sets the position to the first message in the next
transaction.
Note that the transaction grouping property may be negated if messages are
received in the following ways:
Receive specifying a correlation identifier in the selector,
Receive by specifying a message identifier in the selector,
Committing before all the messages of a transaction group have been
received.
If in navigating through the queue, the program reaches the end of the queue while
using the NEXT_MESSAGE or NEXT_TRANSACTION option, and you have specified a
blocking receive, then the navigating position is automatically changed to the
beginning of the queue.
By default, a QueueReceiver, Topic Receiver, or TopicSubscriber uses
FIRST_MESSAGE for the first receive call, and NEXT_MESSAGE for the
subsequent receive calls.
Example Scenario
The get_new_orders() procedure retrieves orders from the OE_neworders_
que. Each transaction refers to an order, and each message corresponds to an
individual book in that order. The get_orders() procedure loops through the
messages to retrieve the book orders. It resets the position to the beginning of the
queue using the FIRST_MESSAGE option before the first receive. It then uses the
next message navigation option to retrieve the next book (message) of an order
(transaction). If it gets an exception indicating all message in the current
group/transaction have been fetched, it changes the navigation option to next
transaction and get the first book of the next order. It then changes the navigation
option back to next message for fetching subsequent messages in the same
transaction. This is repeated until all orders (transactions) have been fetched.
Example Code
public void get_new_orders(QueueSession jms_session)
{
Queue queue;
QueueReceiver qrec;
ObjectMessage obj_message;
BolCustomer customer;
BolOrder new_order;
String state;
12-70 Oracle9i Application Developer’s Guide - Advanced Queuing