hmm, 35 views and nobody wants to answer your queries. This is because information like this can be found by googling or reading the documentation. So please do that, otherwise someone might say RTFM. Since, I am a good guy

, here is the link to Java API documentation on Arrays ->
http://java.sun.com/j2se/1.5.0/docs/...il/Arrays.html
And from the documentation it looks like, "the sorting algorithm is a tuned quicksort" and the Big O of the sort the are using < 2, i.e., n*log(n). So it should be faster thatn other sorts. Also, the speed of sorting algorithm is significant only when you have a large dataset.
Big O and sorting are all huge topics. So I suggest you google for information on these.