title: What happens to stdin data when multiple threads are using Scanners on System.in in Java?
body: <p>Say I have a main program that listens for command line arguments on stdin. This main program spawns a thread to do some stuff, and the thread also needs to listen to stdin. </p>
  
  <p>If two different threads have Scanners on System.in, does one block the other, or do both threads get all data received off stdin? </p>