Where to start with web service development?

Question

I am currently working on a project that is very new to me, and I feel a bit over my head as far as knowledge base is concerned. My request is for references and information to help me expand my knowledge base, as well as recommendations for technologies and methods. I have experience primarily with Java, so all this Windows service stuff is new to me. I am not really asking for a how-to (but if someone has time....I wouldn't object :-P)

The project is as follows:

I am to develop an application in ASP.NET that runs as a process from start-up to shutdown. It will be checking some things in a folder, encrypting some files from that folder, and then check if internet connectivity is available. If it is available, it will be sending those files to a server (via a web service on that server, I believe). If it is not available, it will check every 'insert time interval here' to see if connectivity has become available, at which time it will send the files. Once the files are received by the service, the application will need to recieve some kind of confirmation from the server that the file associated with 'xxxxxxxxxxxxx' uniqueidentifier has been received.

Any explanation of the way that web services work or how to implement file encryption in a desktop app (resource load optimization is a very substantial requirement of this app).

Thanks!

badPanda

Answer 1

There are a couple of things going on here. First off it sounds like you are trying to write a service. Assuming you are writing code for Windows, and that code needs to run regularly and perform some tasks, and you want it to start and stop automatically when the computer is starting or shutting down, a service is ideal for this kind of task. Writing a service isn't too different from writing a normal application except that it has a few extra parts to allow the operating system to control it, and it typically has no user interface.

As far as interacting with a web service goes, typically a web service has a published WSDL (Web Services Description Language) which is just a fancy XML file that contains a description of the service. Most moden programming tools have a feature that loads a WSDL file and creates an object that communicates with the service for you. Then its as simple as creating an instance of that client object and calling the appropriate method. Typically using this created object is as simple as calling normal code, and the object does all the work of converting your parameters to a message, sending them over the network, waiting for the response, and converting the response from the web service back into a return value your client can read.

Encryption methods are going to vary based on operating system and programming language. To get any serious kind of answer you are going to have to add more details.

Really all of this is stuff you should be able to find with google, but one of the ironies of search is sometimes you can't find what you are looking for unless you already know what it is called. Try matching up terms like 'Windows Service' with your programming tools and throw in the word tutorial and you should find lots of good stuff to read. So if you are using Visual Studio and C#, a search like 'Windows Service Visual Studio C# Tutorial' should get you exactly what you need.