Work with the message header

We can add function to a preexisting mediation handler to operate on the message header.

Create or open a basic mediation handler in an EJB project (see Writing a mediation handler. It is useful to have understood the elements of the task Work with the message payload, because some of those elements are used in this task

There are different types of field that we can set in message headers. Importantly, we can set the forward and return routing addresses for messages after they have been mediated at the current destination. In addition there are other fields that we can set, such as priority and reliability for the message and its reply, and the remaining time before the message (or the reply) expires.

1. To set routing addresses in the message header, see Set routing addresses in a message header.

2. To set all other fields in the message header, see Work with non-routing path fields in a message header.

Subtopics

• Set routing addresses in a message header
  We can add function to a pre-existing mediation handler to set routing addresses in the message header.

• Work with non-routing path fields in a message header
  We can work with fields in a message header that identify and affect the behavior of messages.