I'm creating an App and I'm having some questions, I'm a beginner in Java and Android and some things I have no idea how to do.
I need to create a way, to show customers on the screen the "vendors" that are around when they access the application, as the "suppliers" are not fixed locations, they are like taxis in taxi apps , I need this to be updated at all times. Another question is with regard to finding the closest supplier of the customer, my idea is to create a table of updated locations in the web service, make a calculation in every table, using the customer's location and to see the smallest distance, I believe this will take a lot of time and processing.
Another question, is it like authenticating the App on the server? I can not understand this part, everything I see about the HttpClient, does not inform anything of user and password besides Url.
I have more doubts, but these are the ones that are killing me right now.