Android: how to keep the login username stored in the phone as user sending the data to the database server

I've been doing alot of searching around the website but not even sure if i got all the keywords correctly. I've found this link but I needed more coding samples.

How to keep the session of user login?

I would like more sample coding on keeping the user's info when logged in. As that user sends the data to the ser开发者_C百科ver it will identify that user sent that data.

For example, I login as 9999. I send the data 123456789 as a book number to the database server. the database will show

user-9999 book number 123456789

Another thing I need as sample coding for this similar project is how to input a code to completely logout. As user's cant log out and only their supervisor who knows the code can approve and logout for them by putting in the numbers.

Thanks Merrill

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(I'd post this in a comment, but my account doesn't yet have adequate commenting permissions.)

Are you strictly trying to figure out http session management within the Android app, or are you also trying to figure out session management in a server-side application?