Question

I have 2 APIs from 2 different companies that allow me to communicate with their servers in order to process transactions. I am tasked with creating a generic interface to these APIs. I came up with something like this:

IServiceProvider <- ServiceProvider <- CompanyAServiceProvider
IServiceProvider <- ServiceProvider <- CompanyBServiceProvider

In CompanyAServiceProvider I am using the API that they offer to interface with their remote servers. This API from company A throws exceptions that are completely different from Company B’s.

I can handle the exception locally but I don’t really think that suites the situation.

public String purchase(String amount) {
  try {
    request = new Request( RequestIF.NEW_ORDER_TRANSACTION );
  } catch ( InitializationException e ) {
    //do something.
  }
}

Or I can throw this exception to the caller:

public String purchase(String amount) throws Exception {
  request = new Request( RequestIF.NEW_ORDER_TRANSACTION );
}

And let the caller handle just the Exception no matter what that exception is and no matter what API throws it.

How can I write an interface to 2 different APIs and keep it generic when I am dealing with 2 different sets of thrown exceptions. Am I dealing with this correctly? What would be the best choice?

Answer 1

In this case I create my own Exception sublcass and just wrap the actual exception. My API then exposes only my exception.