Using ksoap2 for android, and parsing output data

So the other day, I was asked to check out how we could use soap on Android, preferably with ksoap2 for android, and a public SOAP Web Service. For the latter the TopGoalScorers web service was chosen.

This example will prepare a soap message with one extra variable and value (iTopN, 5) and get a soap object as response.

So after I managed to get a proper soap response, it was time to parse it. I couldn't find any proper already made method to parse it, that actually worked.

You can get the soap objects elements, line by line like this...

...but, this is it! There is no getValue(), or anything like it that would even resemble a parser.

A response soap message from ksoap2 looks like this:

Pretty well structured, but a pain in the ass to work with.
The official documentation suggests a way to implement and register an object with the Marshal interface, but after seeing the string representation above, it seems to be way too complicated. Let's see how we could make things easier, and more importantly, let's try to achieve it in a generalized way.

This is one element:

Obviously I could make something like this fast, but this is only works for the example service.

..but doing this every time, for every response message type, is just multiplying code, and too much work anyway.

After wondering a couple of minutes over the code, it looked as we could create a general method with reflection to do the job.
The method above receives one line of string from the result object, and a class, that has public members. To be able to map the SOAP response values with the corresponding members, the names and types of the member fields have to be exactly the same, as they are in the result response. As in the first example, we used the TopGoalScorers method, to test the parser, it had the following fields: sName, iGoals, sCountry, sFlag. For our web service example the result class (aka Business Object) is:

And here comes the parser implementation. Please note, that in the current form this only works with primitive types, like String, int, Integer, float and Float.

Now this class can be easily reused for parsing any response with primitive types, and it provides the result in a convenient form to work with.
Usage:

We know, that there is still room for improvements. The error reporting could be done in a sophisticated way for example. Or maybe we could do an implementation, that not only parses one object, but a list of objects. With this article we just wanted to introduce the basic idea.