Android App interaction with Web

I am new to Android Development and have a background in Web development. I want to create an application on Android where i can interact with Web that will serve content.

What i want to learn

1. Authenticating users via Facebook/Twitter and create an Profile on my web app
2. How to serve content from the web to the mobile app. Should i have a single point of contact to the web app or for each activity i need to have different contact points.
3. on uploading an image to the web app i would like to create different size versions. how do i do it ?
4. is 开发者_Python百科there any start to end tutorial for a sample web - mobile app like this kind ?

What you describe sounds like an API to me.

To 1: When creating an API, authentication is often done using OAuth. But what you are describing (using a Facebook/Twitter account to log into your site) sounds more like OpenID.

To 2: When creating an API, most of the time you'll want to have one API-call (so physically one site) for every content-type. Say one site for all your Blog-Posts and one for only showing one but with more details (for example).

The way responses from the API are often realized is using either JSON or XML.

To 3: If this is about how you would process the Image on your Server (using PHP for example), this will answer your question.

To 4: I've given you some idea on how to start this project. But i don't think there are tutorials which cover all of those steps.

A great way to start creating your own API is to use APIs from other sites (like StackOverflow or GitHub) to see how they managed to do thinks and learn from that.