0

When I'm tasked with dealing with connecting to web services, I've always found the appropriate .wsdl file, ran WSDL2Java.bat, and incorporated those Java files into my Java project. Then I've successfully completed my project that needs to access data via web services.

My question is, are there other ways to use the .wsdl file to access web services? ( I'm not talking about creating classes for different languages ). For example, I have documentation describing one company's web services. The examples it shows in it's documentation are essentially dumps of HTTP Post requests. Is this "web services"? It looks to me that the .wsdl file is merely used as a reference to make the correct Post requests. I could just make text templates and plug in the right values, and send them out, right? I really feel like I'm missing something here.

Am I a web-services illiterati?

joe7pak
  • 300
  • 1
  • 4
  • 16

1 Answers1

0

To call a SOAP web service over HTTP you just need to send it a properly formatted XML with a POST request. That's it! How you build the request is irrelevant as long as it conforms to the SOAP protocol and the payload corresponds to a proper web service operation that exists on the particular web service you are calling.

But how do you know how to build the proper payload?

The web service needs to have some sort of documentation otherwise you don't know what to put inside the XML. The documentation can be whatever you like as long as people can use it to build valid requests. WSDL fits this criteria but has an extra advantage: you can feed it to a tool that generates code. That code knows how to handle all the SOAP details and exposes objects and methods to your application.

What would you prefer? Generating code from the WSDL in a few minutes and be able to call whatever operation on the web service or, build the requests and parse the responses by hand and spend hours or days doing so. What would your boss or company prefer? :)

It looks to me that the .wsdl file is merely used as a reference to make the correct Post requests. I could just make text templates and plug in the right values, and send them out, right?

Right! But you also have to consider your productivity as an employee in one case as opposed to the other.

Community
  • 1
  • 1
Bogdan
  • 23,890
  • 3
  • 69
  • 61
  • Just a thought ... yes, I can build .java file ( or .cpp, or .py, etc. ) by processing the .wsdl file with some tool. Is there a tool that would directly generate the HTTP Post requests, and send them? Of course that should be on-demand vice a one-time code generation. What do you think? – joe7pak Aug 17 '14 at 01:36
  • @joe7pak: what you are talking about is called dynamic invocation and it's harder to do, although not impossible (see here for an idea: http://stackoverflow.com/questions/8996295/convert-wsdl-to-its-repective-http-bindings/9056358#9056358). This might be easier in dynamic languages like Python but even there the client needs to "understand" what's in the WSDL it's getting back. – Bogdan Aug 17 '14 at 10:14