Java Programming

Hi, what are the exact advantages and disadvantages among using Timer, using ScheduledExecutorService and just using Thread (Thread.sleep(...))?
For the simple task which needs to poll some values by some interval (the interval is not supposed very accurate, maybe about 5 seconds just ok), is it ok for just using Thread, like:

run() {
  while(isRunning) {
     Thread.sleep(5000);
     //do something
  }
}

?