In the simplest embodiment java long calculation performed

In doing routine testing when some performance will be performed by performing long time to judge, java simplest way as follows:
// start time
. Long startL = new Date () getTime (); // here need to import java.util. *; package
exceFun ();
long endl new new = a Date () the getTime ();.
// execution time
System.out.println ( "startL:" + senStrat + "endL:" + senEndL + " length when executed:" + ( senEndL-senStrat) + "msec");