14.2. WSIT Configuration and WS-Policy Assertions
WSIT features are enabled and configured using a mechanism defined by the Web Services Policy Framework (WS-Policy) specification. A web service expresses its requirements and capabilities through policies embedded in the service's WSDL description. A web service consumer, or client, verifies that it can handle the expressed requirements and, optionally, uses server capabilities advertised in policies.
Each individual WSIT technology, such as Reliable Messaging, Addressing, or Secure Conversation, provides a set of policy assertions it can process. Those assertions provide the necessary configuration details to the WSIT runtime to enable proper operation of the WSIT features used by a given web service. The assertions may specify particular configuration settings or rely on default settings that are predetermined by the specific technology. For instance, in the snippet shown below, the wsrm:InactivityTimeout setting is optional and could be omitted. The following snippet shows WS-Policy assertions for WS-Addressing and WS-Reliable Messaging:
This snippet is valid in either a WSIT configuration file (wsit-package.service.xml) or in a Web Services Description Language (WSDL) file. Java-first web services use the WSIT configuration file, while WSDL-first web services rely exclusively on the policy elements in the WSDL file. This particular snippet is from the WSIT configuration file in the example, wsit-enabled-fromjava/etc/wsit-fromjava.server.AddNumbersImpl.xml.