Overview of SOAP Message Handlers

Overview of SOAP Message Handlers

Some Web services need access to the SOAP message, for which you can create SOAP message handlers. A SOAP message handler provides a mechanism for intercepting the SOAP message in both the request and response of the Web service.

A simple example of using handlers is to access information in the header part of the SOAP message. You can use the SOAP header to store Web service specific information and then use handlers to manipulate it.

You can also use SOAP message handlers to improve the performance of your Web service. After your Web service has been deployed for a while, you might discover that many consumers invoke it with the same parameters. You could improve the performance of your Web service by caching the results of popular invokes of the Web service (assuming the results are static) and immediately returning these results when appropriate, without ever invoking the back-end components that implement the Web service. You implement this performance improvement by using handlers to check the request SOAP message to see if it contains the popular parameters

JWS Annotations Used To Configure SOAP Message Handler Chains:

JWS Annotation	Description
javax.jws.HandlerChain	Associates the Web service with an externally defined handler chain. Use this annotation when multiple Web services need to share the same handler configuration, or if the handler chain consists of handlers for multiple transports.
javax.jws.soap.SOAPMessageHandlers	Specifies a list of SOAP handlers that run before and after the invocation of each Web service operation. Use this annotation (rather than @HandlerChain) if embedding handler configuration information in the JWS file itself is preferred, rather than having an external configuration file. Note; This annotation works with JAX-RPC Web services only.
javax.jws.soap.SOAPMessageHandler	Specifies a single SOAP message handler in the @SOAPMessageHandlers array.