Generally a web service talks to a remote database to fetch required data. In my case, I have a web service that gets the data from another web application (given the http url). Both are java based applications. How do I communicate with the remote web application ? via HttpUrlConnection?

I need to send JSON Objects and receive JSON Arrays. Are there any code examples that I can refer to?

Basically, the whole system would work like this:
Client (say a mobile app) accesses the web service resource via a URL and the web service in turn talks to the server/data source (another web application), sends the request for data and receives response from the data source. Should the httpUrlConnections be threaded? Or should I just use one connection per request?

Please advise.