Question

I am working on a project that. It will connect to a remote host using tcp sockets from a service. And interact with it for getting and sending data.

The flow, I have planned is;

a singleton socket class. Which returns a connected socket refference;

an activity to ask user for remote server’s ip and port.
a service triggered(intent) by the activity with the parameters of ip:port.
service will get the socket using singleton socket class.
and then service will read a data; parse it and show user for user actions in a new action window ( intended).
after user completed the action; result will be sent to the server. and new request will be read.

problem/query is here;

• when you come back to the service for second data read operation; will the socket be there ? (or garbage collected )
  because after data read operation started no new connection accepted.

• will the first service die after calling the user actions activity ?

• what happens if I call the service using startService from an activity, a new service created or the existing before started service called back again ?

• how can I let the service live for ever unless I said it to die.

Sorry, If I am asking silly questions.

Answer 1

Here’s how I see it:

when you come back to the service for second data read operation; will
the socket be there ? (or garbage collected ) because after data read
operation started no new connection accepted.

If the object is static and has the socket as a member variable it will most likely be there, you should have safeguards in your single pattern to shield from this problem (if single==null){...}, you could also try managing it by overriding the Application class and adding a factory method in there. You need to make sure the socket is open and closed correctly and not just left hanging as this could create problems

EDIT:

Whether the actual socket is still open will depend on the timeout of the socket

will the first service die after calling the user actions activity ?

Services need to be told to stop and so it will not die

what happens if I call the service using startService from an
activity, a new service created or the existing before started service
called back again ?

If the service is running, the it will not create another, it will call the onStartCommand() of the running service

how can I let the service live for ever unless I said it to die.

This is default behavior