Day: 9 September 2010

A WSDL file contains a reference to an XSD document which defines the data structures which can be sent to the service over SOAP. In an XSD, you can define a Type for an element, or things like the elements cardinality, whether its optional or required, etc. When the web server hosting a web service is called, it receives a SOAP envelope which tells it which web service is being called. It could (and you might expect it does) validate the body of the SOAP message against the XSD in the WSDL... but it doesn't. Is this bad? Well, most clients will be generated from the WSDL, so you can assume that the type safety is respected. Saying that, it's not something the server can guarantee, so it needs to check that say a field that is supposed to contain a date, really does contain a date, and not some garbled text that is meant to be a date. But more importantly, something which a client does not guarantee, is whether all required fields in the data structure are actually present. To check this, you can validate incoming SOAP bodies against the XSD. The way to do this, is by using "Handlers". The JAX-WS specification defines two kinds, namely, SOAP Handlers and Logical Handlers. The SOAP kind is useful for accessing the raw SOAP envelope, for example to log the actual SOAP message. The logical kind is useful for accessing the payload as an XML document. To configure a handler,…

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