Creating a Durable Subscriber for a JMS Topic with Selector

Figure 15-16 Use Case Diagram: Publish-Subscribe - Create a Durable Subscriber for a JMS Topic with Selector

Text description of the illustration adq15jps15.gif

To refer to the table of all basic operations having to do with the Operational Interface see: "Use Case Model: Operational Interface -- Basic Operations"

Purpose

Create a durable subscriber for a jms topic with selector.

Usage Notes

The client creates a durable subscriber by specifying a subscriber name and JMS topic. Optionally, a message selector can be specified. Only messages with properties matching the message selector expression are delivered to the subscriber. The selector value may be null. The selector can contain any SQL92 expression that has a combination of one or more of the following:

• JMS Message header fields or properties: JMSPriority (int), JMSCorrelationID (string), JMSType (string), JMSXUserID (string), JMSXAppID (string), JMSXGroupID (string) JMSXGroupSeq (int)

  For example:

  JMSPriority < 3 AND JMSCorrelationID = 'Fiction' 
  
  

User defined message properties

For example:

color IN ('RED', BLUE', 'GREEN') AND price < 30000 

Operators allowed are:

• logical operators in precedence order NOT, AND, OR comparison operators

• =, >, >=, <, <=, <>, ! (both <> and ! can be used for not equal)

• arithmetic operators in precedence order +,- unary, *,/, +,-

• identifier [NOT] IN (string-literal1, string-literal2, ..)

• arithmetic-expr1 [NOT] BETWEEN arithmetic-expr2 and arithmetic-expr3

• identifier [NOT] LIKE pattern-value [ESCAPE escape-character]

• pattern-value is a string literal where % refers to any sequence of

• characters and _ refers to any single character. The optional

• escape-character is used to escape the special meaning of the

• '_' and '%' in pattern-value

• identifier IS [NOT] NULL

A client can change an existing durable subscription by creating a durable TopicSubscriber with the same name and a different message selector. An unsubscribe call is needed to end the subscription to the topic.

Syntax

• Java (JDBC): Oracle9i Supplied Java Packages Reference,oracle.jms, AQjmsTopicPublisher.publish

Example

Example 1 - subscribe specifying selector

TopicConnectionFactory    tc_fact   = null;
TopicConnection           t_conn    = null;
TopicSession              jms_sess;
TopicSubscriber           subscriber1;
Topic                     shipped_orders;
int                       myport = 5521;
AQjmsAgent[]              recipList;    
  
/* create connection and session */
tc_fact = AQjmsFactory.getTopicConnectionFactory("MYHOSTNAME",
                                                  "MYSID", myport, "oci8");
t_conn = tc_fact.createTopicConnection("jmstopic", "jmstopic");
jms_sess = t_conn.createTopicSession(true, Session.CLIENT_ACKNOWLEDGE);    
  
shipped_orders = ((AQjmsSession )jms_sess).getTopic("OE", "Shipped_Orders_
Topic");

/* create a subscriber */
/*  with condition on JMSPriority and user property 'Region' */
subscriber1 = jms_sess.createDurableSubscriber(shipped_orders, 
'WesternShipping',
                                "JMSPriority > 2 and Region like 'Western%'", 
false);