Advanced Queuing - Oracle

Listen to Single-Consumer Queue (Timeout of Zero).
DECLARE
Agent_w_msg aq$_agent;
My_agent_list dbms_aq.agent_list_t;
Listening to One or More Single-Consumer Queues
BEGIN
/* NOTE: MCQ1, MCQ2, MCQ3 are multiconsumer queues in SCOTT’s schema
* SCQ1, SCQ2, SCQ3 are single-consumer queues in SCOTT’s schema
*/
Qlist(1):= aq$_agent(NULL, 'scott.SCQ1', NULL);
Qlist(2):= aq$_agent(NULL, 'SCQ2', NULL);
Qlist(3):= aq$_agent(NULL, 'SCQ3', NULL);
/* Listen with a time-out of zero: */
DBMS_AQ.LISTEN(
Agent_list => My_agent_list,
Wait => 0,
Agent => agent_w_msg);
DBMS_OUTPUT.PUT_LINE('Message in Queue :- ' || agent_w_msg.address);
DBMS_OUTPUT.PUT_LINE('');
END;
Java(JDBC):ListentoQueues
public static void monitor_status_queue(Connection db_conn)
{
AQSession aq_sess;
AQAgent[] agt_list = null;
AQAgent ret_agt = null;
try
{
/* Create an AQ Session: */
aq_sess = AQDriverManager.createAQSession(db_conn);
/* Construct the waiters list: */
agt_list = new AQAgent[3];
agt_list[0] = new AQAgent(null, "scott.SCQ1",0);
agt_list[1] = new AQAgent (null, "SCQ2",0);
agt_list[2] = new AQAgent (null, "SCQ3",0);
/* Wait for order status messages for 120 seconds: */
Operational Interface: Basic Operations 11-25