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web-servicesjax-ws

Besides annotations, how do I distinguish JAX-WS from JAX-RPC?

Two questions

Two questions on JAX-WS and JAX-RPC

  1. Besides annotations, how do I distinguish JAX-WS from JAX-RPC?

  2. What simple POCs can I do to appreciate JAX-WS is better to use than JAX-RPC? (besides the reason that JAX-RPC is the older version). I have read all about JAX-WS and it's advantages but I find it card to figure out thinking of concrete examples or simple proof of concept that would prove that its better use it than JAX-RPC.

Can anyone help?

Solution

  • Your first question is covered by this one. To summarize, there are descriptor files present for JAX-RPC, since it uses XML mapping documents to describe reflection-based rules for marshal/unmarshal.

    As for your second question, I suggest writing the same HelloService web service (provider) using both frameworks. I think you'll find JAX-WS much easier, if for no other reason than finding tutorial documentation. Use two web modules and follow tutorials to create the same functionality.

    Take a look at the artifacts for both. Also experiment with adding complex Java types as input or output. Notice that JAX-RPC cannot automatically convert many WSDL/schema constructs to a Java equivalent - a great side by side comparison article (and series) is here.

    A personal anecdote - due to the JAXB underpinnings, the JAX-WS service will be much more forgiving if the request message has small deviations from the WSDL such as unexpected input elements, etc. Why is this important? Versioning & maintenance. With JAX-RPC, it was much more difficult to update the service provider with new fields without breaking JAX-RPC client applications, and vice versa.

    Spec Time

    I've seen it mentioned that JAX-RPC is deprecated as of JavaEE 6. I don't see that wording specifically (it is listed for server implementors as "proposed optional"; the PDF spec says the following:

    EE.12.2.3

    JAX-WS JAX-WS, along with JAXB and the Metadata for Web Services specification, provides simpler and more complete support for web services than is available using the JAX-RPC technology. Applications that provide web services using JAX-RPC should consider migrating to the JAX-WS API.

    (emphasis mine).

    The JavaEE 7 spec lists JAX-RPC not only as optional (for server implementors); it also includes it in the list of "pruned Java technologies" - candidates for outright removal in subsequent JavaEE spec versions.

    All this to say: you don't earn your way out of the JavaEE specification if you're the better spec.