Establishing JMS Connections

Table 6-1 JMS Destinations Used by the Process Engine

This JMS destination . . .	Of JMS Type . . .	Is the destination for . . .
Name: WLI_BPM_Audit JNDI Name: com.bea.wli.bpm.Audit	Topic	Audit messages.
Name: WLI_BPM_Error JNDI Name: com.bea.wli.bpm.Error	Topic	Error messages. For more information, see Monitoring Workflow Exceptions.
Name: WLI_BPM_Event JNDI Name: com.bea.wli.bpm.Event	Queue	Events. All incoming messages are processed via message-driven beans. A message-driven bean is an EJB that acts as a message consumer in the WebLogic JMS messaging system. As with standard JMS message consumers, message-driven beans receive messages from a JMS queue or topic, and perform business logic based on the message contents. In addition, message-driven beans support concurrent processing for JMS destinations. A system administrator can define multiple event queues, if required, as described in Connecting to JMS. In this case, the system administrator must also generate the associated message-driven beans using the utility described in Generating Message-Driven Beans for Multiple Event Queues, and the application developer must specify the appropriate destination for a particular event. You can guarantee the delivery and sequential processing of messages using the methods described in Guaranteeing Message Delivery and Guaranteeing Sequential Processing of Messages, respectively. Note: For backward compatibility, the TopicRouter bean automatically reroutes any messages bound for the wlpiEvent topic, which is supported by WebLogic Process Integrator Release 1.2.1 and earlier releases, to the WLI_BPM_Event queue.
Name: WLI_BPM_Notify JNDI Name: com.bea.wli.bpm.Notify	Topic	Worklist notifications. Enables a worklist client to refresh its display dynamically and obtain task object data via the delivered com.bea.wlpi.common.TaskInfo object. For messages posted to the WLI_BPM_Notify topic, the following message properties must be defined to ensure delivery to appropriate subscribers: orgId: string specifying the ID of the organization assigneeId: string specifying the ID of the assignee (user or role) role: Boolean flag specifying whether or not the assignee is a role (true, false) action: string specifying which of the following actions has been performed on the task: - assigned: task assigned to user - update: task state has changed - remove: task removed from list of user tasks A worklist client can define a selector to filter messages based on these message properties. For an example of using a selector to filter messages, see Example of Connecting to a JMS Topic. For more information about JMS, see Programming WebLogic JMS in the BEA WebLogic Server document set, available at the following URL: http://download.oracle.com/docs/cd/E13222_01/wls/docs70/jms/index.html
Name: WLI_BPM_Timer JNDI Name: com.bea.wli.bpm.Timer	Queue	Time processor triggers (internal use only).
Name: WLI_BPM_ValidatingEvent JNDI Name: com.bea.wli.bpm.ValidatingEvent	Queue	Events that require DTD or schema validation. If XML messages reference a DTD or schema, validates the content.
Name: WLI_FailedEvent JNDI Name: com.bea.wli.FailedEvent	Queue	Messages that have been unsuccessfully delivered and the maximum number of retries has been consumed. The maximum number of retries is configurable for each JMS destination using the Redelivery-Limit attribute. For more information, see the description of the JMSTemplate element within the BEA WebLogic Server Configuration Reference at the following URL: http://download.oracle.com/docs/cd/E13222_01/wls/docs70/config_xml/index.html When a failed message is received, an entry is logged to the log file. If desired, you can develop a custom event handler to handle failed messages.

Argument	Description
-queue queue_name	Name of the custom queue for which you want to generate the message-driven bean. This argument is required.
-min minimum	Minimum number of message listeners allocated to handle unordered messages. Unordered messages are those that do not need to be processed in a specific order, as described in Guaranteeing Sequential Processing of Messages. minimum specifies an integer value that must be less than the maximum value. This argument is optional and defaults to 0.
-max maximum	Maximum number of message listeners allocated to handle unordered messages. maximum specifies an integer value that must be less than or equal to 100, and greater than the minimum value specified. This argument is optional and defaults to 5.
-order ordernum	Number of message listeners allocated to handle ordered messages. Ordered messages are those that require messages to be processed in a specific order, as described in Guaranteeing Sequential Processing of Messages. ordernum specifies a prime number less than or equal to 31. This argument is optional and defaults to 0.
-transact	Flag specifying that the transaction is required.
-validate	Flag specifying that you want to validate all messages received on the queue against the DOC-TYPE tag in the XML JMS message. This argument is optional.
-timeout seconds	Transaction timeout in seconds. This argument defaults to 30 seconds. This value is only used if the transact flag is not set. If the transact flag is set, the utility uses the WebLogic Server transaction timeout value, which can be set using the Administration Console and defaults to 30.
-help	Flag specifying that you want to display command usage syntax. This argument is optional.

Argument

Description

-queue queue_name

Name of the custom queue for which you want to generate the message-driven bean.

This argument is required.

-min minimum

Minimum number of message listeners allocated to handle unordered messages. Unordered messages are those that do not need to be processed in a specific order, as described in Guaranteeing Sequential Processing of Messages. minimum specifies an integer value that must be less than the maximum value.

This argument is optional and defaults to 0.

-max maximum

Maximum number of message listeners allocated to handle unordered messages. maximum specifies an integer value that must be less than or equal to 100, and greater than the minimum value specified.

This argument is optional and defaults to 5.

-order ordernum

Number of message listeners allocated to handle ordered messages. Ordered messages are those that require messages to be processed in a specific order, as described in Guaranteeing Sequential Processing of Messages. ordernum specifies a prime number less than or equal to 31.

This argument is optional and defaults to 0.

-transact

Flag specifying that the transaction is required.

-validate

Flag specifying that you want to validate all messages received on the queue against the DOC-TYPE tag in the XML JMS message.

This argument is optional.

-timeout seconds

Transaction timeout in seconds. This argument defaults to 30 seconds.

This value is only used if the transact flag is not set. If the transact flag is set, the utility uses the WebLogic Server transaction timeout value, which can be set using the Administration Console and defaults to 30.

-help

Flag specifying that you want to display command usage syntax.

This argument is optional.

protected static final String JNDI_FACTORY= "weblogic.jndi.WLInitialContextFactory";
protected static final String JMS_FACTORY= "javax.jms.TopicConnectionFactory";
protected static final String NOTIFY_TOPIC="com.bea.wli.bpm.Notify";

try {
Hashtable env = new Hashtable();
env.put(Context.PROVIDER_URL, wlpi.getUrl());
env.put(Context.INITIAL_CONTEXT_FACTORY, JNDI_FACTORY);
env.put("weblogic.jndi.createIntermediateContexts", "true");

Context ctx = new InitialContext(env);

if (tsubscriber != null) tsubscriber.close();
String selector = "orgId = '" +
wlpi.getWorklist().getActiveOrganization() + "' AND assigneeId = '" +
wlpi.getUserId() + "' AND NOT role" + " AND action = 'assigned'";
tsubscriber = tsession.createSubscriber(topic, selector, false);

import javax.swing.SwingUtilities;
public void onMessage(Message msg) {
String action;
TaskInfo task;
try {
// We're only interested in ObjectMessages with a TaskInfo
// payload.
if (!(msg instanceof ObjectMessage))
return;
Object data = ((ObjectMessage)msg).getObject();
if (!(data instanceof TaskInfo))
return;
action = msg.getStringProperty("action");
task = (TaskInfo)data;
} catch (JMSException e) {
e.printStackTrace();
return;
}

if (action.equals("update"))
taskUpdated(task);
else if (action.equals("remove"))
taskDeleted(task);
}

private void taskDeleted(final TaskInfo task) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
vTasks.remove(task);
int row = vDisplayedTasks.indexOf(task);
if (row != -1) {
vDisplayedTasks.remove(row);
model.fireTableRowsDeleted(row, row);
}
}
});
}