How to get a meaningful result from subtracting 2 nanoTime objects?

Question

I created a filter that monitors the length of a request.

long start = System.nanoTime();

...

long end = System.nanoTime();

How can I get the number of milliseconds from this now?

Answer 1

(end - start) / 1000000

1 microsecond = 1000 nanoseconds

1 millisecond = 1000 microseconds

Note, that the result will be rounded down, but you usually don't get true nanosecond accuracy anyway (accuracy depends on the OS). From the Javadoc on nanoTime():

This method provides nanosecond precision, but not necessarily nanosecond accuracy.