= Opening Documents =

Besides crawling resources, we should also be able to open them in their default viewer.

At first this may sound like a job for the !DataAccessor, which after all has knowledge about how to load the stream from the physical source.

On second thought, I believe that for the opening of files you need some other service, parallel to !DataAccessor, that is also scheme-specific and that takes care of opening the files. Reasons:

 * !DataAccessors actually retrieve the files/webpages/..., which is often not necessary for some !DataObject openers. For example, for opening a local file you can instruct Windows to do just that. Similarly, a web page can be retrieved and shown by a web browser, there is no need for our codebase to retrieve the contents and feed it to the browser.

 * There may be several alternative ways of opening a resource. For example, the java.net JDIC project contains functionality for opening files and webpages, we have our own classes to do that, there may be customer-specific implementations, etc.

This may be a good reason to decouple this functionality from the !DataAccessor and run it in a parallel service.