DataProvider supporting count and fetch in one request - for WebServices and spring-data page feature

I tired to implement a DataProvider which supports counting and fetching in one request, e.g. for querying webservices or using spring-datas Page feature.

I've created a class implementing FetchCallback and CountCallback. It checks if the query changed, so that a new request is needed and
stores the Page result, so that after a count call the fetch call is not passed to the backend.

The Problem is, that a grid does the first call to CountCallback.count(Query query) with a limit of Integer.MAX_VALUE which returns the whole database.

If the later limit, offset and sortOrders would be also passed to count, then integrating spring-data would be much easier.

Start by examining DataProvider, FetchCallback, CountCallback, and Query, then reproduce the initial CountCallback.count(Query) call with a limit of Integer.MAX_VALUE. The work is complete when count receives the relevant limit, offset, and sortOrders so web-service and spring-data Page integrations can avoid fetching the whole database.