第15章 Filter Expressions and Message Selectors

Predefined Queues. When pre-defining a queue, a filter expression can be defined for it. Only messages that match the filter expression will enter the queue. The configuration snippet below shows a queue definition that includes a filter:

<subsystem xmlns="urn:jboss:domain:messaging-activemq:4.0">
  ...
  <queue
    name="myQueue"
    filter="FILTER_EXPRESSION"
    ...
  />
  ...
</subsystem>

To create queue with a selector in the management CLI you would use something like following command:

jms-queue add --queue-address=QUEUE_ADDRESS --selector=FILTER_EXPRESSION

Core bridges can be defined with an optional filter expression, only matching messages will be bridged. Below is a snippet from a sample configuration file where the messaging-activemq subsystem includes a bridge with a filter.

<subsystem xmlns="urn:jboss:domain:messaging-activemq:4.0">
  ...
  <bridge
    name="myBridge"
    filter="FILTER_EXPRESSION"
    ...
  />
  ...
</subsystem>

Diverts can be defined with an optional filter expression, only matching messages will be diverted. See Diverts for more information. The example snippet below shows a Divert using a filter:

<subsystem xmlns="urn:jboss:domain:messaging-activemq:4.0">
  ...
  <divert
    name="myDivert"
    filter="FILTER_EXPRESSION"
    ...
  />
  ...
</subsystem>