EMS Extensions to Jakarta Messaging Messages

The Jakarta Messaging specification details a standard format for the header and body of a message. Properties are provider-specific and can include information on specific implementations or enhancements to Jakarta Messaging functionality. See EMS Message Properties for the list of message properties that are specific to EMS.

In addition to the EMS message properties, EMS provides a select number of extensions to Jakarta Messaging. These are:

• The Jakarta Messaging standard specifies two delivery modes for messages, PERSISTENT and
  NON_PERSISTENT. EMS also includes a RELIABLE_DELIVERY mode that eliminates some of the overhead associated with the other delivery modes. See RELIABLE_DELIVERY.
• For consumer sessions, you can specify a NO_ACKNOWLEDGE mode so that consumers do not need to acknowledge receipt of messages, if desired. EMS also provides an EXPLICIT_CLIENT_ACKNOWLEDGE and EXPLICIT_CLIENT_DUPS_OK_ACKNOWLEDGE mode that restricts the acknowledgment to single messages. See Message Acknowledgement.
• EMS extends the MapMessage and StreamMessage body types.

  TIBCO Enterprise Message Service adds these two extensions to the MapMessage and StreamMessage body types:

  • You can insert another MapMessage or StreamMessage instance as a submessage into a MapMessage or StreamMessage, generating a series of nested messages, instead of a flat message.
  • You can use arrays as well as primitive types for the values.

    These extensions add considerable flexibility to the MapMessage and StreamMessage body types. However, they are extensions and therefore not compliant with Jakarta Messaging specifications. Extended messages are tagged as extensions with the vendor property tag JMS_TIBCO_MSG_EXT.