CODEWITHSUNDEEP
web-servicesdesign-patterns
Frode Lillerud
Frode Lillerud

Reputation: 7394

Design pattern for working with different versions of webservices?

I'm looking for a design pattern to solve an architectual issue I'm having.

I use some webservices that are kinda the same but not exactly. For each new version of the webservices there might be a few more methods available, but for the most part they are basically the same.

I want to write an abstractionlayer that works regardless of which version of the webservices I'm communicating with. Obviously if I'm using a method that only exists in the newer versions of the webservices I will get some sort of error, but that is OK. I can handle those.

The reason I want this abstraction layer is to avoid a tight coupling between my application and the version of the webservices it is communicating with.

What are my options when it comes to design patterns for my abstraction layer? I see there is one pattern called Adapter, and another one called Bridge. Will any of those do in this situation? Any help is appreciated!

Edit - for clarity here is a drawing. enter image description here

Sometimes I want my application to talk to webservices version 1, and other times I want it to use webservices version 2. It depends on who is using the client application.

The client application shouldn't relly know or care which version it is talking to. The only exception is that if it uses a method that is only available in some of the versions I need to handle that gracefully (tell the user that they have installed an old version of the webservices).

Upvotes: 5

Views: 2423

Answers (2)

Juned Ahsan
Juned Ahsan

Reputation: 68715

I will suggest to use the FACADE pattern. You may go through the following link to understand more about it. http://javapapers.com/design-patterns/facade-design-pattern/

Facade is to provide the abstraction and a seamless layer for clients to interact. It hides all the internal complexities, as in your case client need to find the correct version of web service it can interact with. Lets assume you have different version of webservices, and input json/xml structures have changed in different versions. Facade will accept the client call, it will validate the input against different version of web services and then call the correct web service version. If you don't have facade layer then client will have to struggle to find the correct webservice version and it will have to send multiple calls before reaching the correct web service.

Upvotes: 2

Wiktor Zychla
Wiktor Zychla

Reputation: 48230

That would be a factory. You could even use a builtin ChannelFactory or come up with your own. Anyway, a facttory lets you change the implementation without changing client's contract.

Upvotes: 3

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