Trigger new task for every message: enabled

The listener connects to the JMS source (queue/topic) and responds to each incoming message by triggering the selected task (e.g. graph or jobflow). The connection to the source is not interrupted during the process.

Trigger new task for every message: disabled

The listener connects to the JMS source (queue/topic) and waits for a message. Once the message is received, it stays in the queue, the listener disconnects from the source and responds to the message by triggering the selected task (e.g. graph or jobflow). Once the task is finished, the listener reconnects to the source and waits for another message. This way, the triggered task can use JMSReader to connect to the same source as the listener which, in some use cases, increases performance.

The listener is disconnected from the source for the duration of the triggered task, but for the maximum of the task.jms.callback.timeout value.

This attribute is useful only in a Cluster environment. It is a node ID where the listener should be initialized. If it is not set, the listener is initialized on all nodes in the Cluster.

In the Cluster environment, each JMS event listener has a Node IDs attribute which may be used to specify the Cluster node which will consume messages from the queue/topic. There are the following possibilities:

In a standalone environment, the Node IDs attribute is ignored.

A full class name of the javax.naming.InitialContext implementation. Each JMS provider has its own implementation. For example, Apache MQ has org.apache.activemq.jndi.ActiveMQInitialContextFactory. If it is empty, the Server uses a default initial context.

The specified class must be on the web-app classpath or application-server classpath. It is usually included in one library with a JMS API implementation for each specific JMS broker provider.

If false, the message consumer is connected to the broker as 'non-durable', so it receives only messages which are sent while the connection is active. Other messages are lost.

If the attribute is true, the consumer is subscribed as 'durable' so it receives even messages which are sent while the connection is inactive. The broker stores such messages until they can be delivered or until the expiration is reached.

This switch is useful only for Topics destinations, because Queue destinations always store messages until they can be delivered or the expiration is reached.

Please note that consumer is inactive e.g. during server restart and during short moment when the user updates the "JMS message listener" and it must be re-initialized. So during these intervals, the message in the Topic may get lost if the consumer does not have the durable subscription.

If the subscription is durable, client must have ClientId specified. This attribute can be set in different ways in dependence on JMS provider. E.g. for ActiveMQ, it is set as a URL parameter tcp://localhost:1244?jms.clientID=TestClientID.

Available only when Durable subscriber is true. By default, a durable subscriber name is generated automatically in the subscr_[clusterNodeId]_[listenerId] format; therefore, a subscriber has a different name on each Cluster node. Using this attribute, you can specify a custom subscriber name that will be identical on all Cluster nodes.

This query string can be used as a specification of conditions for filtering incoming messages. Syntax is well described on Java EE API web site. It has different behavior depending on the type of consumer (queue/topic):

Queue: Messages that are filtered out remain in the queue.

Topic: Messages filtered out by a Topic subscriber's message selector will never be delivered to the subscriber. From the subscriber's perspective, they do not exist.

A Groovy code may be used for additional message processing and/or for refusing a message. Both features are described below.

See below for details. It contains values (String or converted to String) read from a message and it is passed to the task which may then use them. For example, the execute graph task passes these parameters to the executed graph.

See below for details. Contains values (Object, Stream, etc.) read or proxied from the message instance and it is passed to the task which may then use them. For example, the execute graph task passes it to the executed graph as dictionary entries.

For each message property, one entry is created where "key" is made of the JMS_PROP_ prefix and property key.

If the message is an instance of MapMessage, for each map entry, one entry is created where "key" is made of the JMS_MAP_ prefix and map entry key. Values are converted to String.

JMSMessageID is a String value that should function as a unique key for identifying messages in a historical repository. The exact scope of uniqueness is provider-defined. It should at least cover all messages for a specific installation of a provider, where an installation is some connected set of message routers.

The time the message expires, which is the sum of the time-to-live value specified by the client and the GMT at the time of the send.

The JMS API defines ten levels of priority value (0 = lowest, 9 = highest). In addition, clients should consider priorities 0-4 as gradations of normal priority and priorities 5-9 as gradations of expedited priority.

The time a message was handed off to a provider to be sent. It is not the time the message was actually transmitted, because the actual send may occur later due to transactions or other client-side queueing of messages.

An instance of java.io.InputStream. Accessible only for TextMessage, BytesMessage, StreamMessage, ObjectMessage (only if a payload object is an instance of String). Strings are encoded in UTF-8.

An instance of String. Only for TextMessage and ObjectMessage, where a payload object is an instance of String.