Android : how to call a route of node server from android app

I am working on android for the first time, I just want to connect my android app with node server on a button click. my node server is running on localhost and my mobile is also connected to the same network. can it be possible to connect my android app with running node server. what i have to do to call a route of server that only prints "Hello world" in console.log of server. If possible please help me with the code. Thanks.