System.nanoTime is 1.5+. 1.5 has been out for around three years now. There shouldn't be a problem compiling without a main (most classes don't have a main). However, running is open to dispute. Java WebStart, for instance, does not initialise the main class as a separate step before finding and executing the main method (and it will complain if the method is defined in the wrong class loader). Terminal handling in Java is a bit limited (and available is not guaranteed to return anything other than zero), although there is Console.readPassword in 1.6.

IIRC, the getting caught in the left hand side was to do with starting position. But I forget now. I don't have many characters to spare.