Measure the time it takes for Java class to run

Question

Is it possible to start a timer in a Java class, so that I may measure the time it takes for its task?

I tried with

Date d2 = (Date) session.getAttribute("date2");
Date d1 = new Date();

long seconds = (d2.getTime()-d1.getTime())/1000;
System.out.println("time: " + seconds);

Date dates = new Date();                
session.setAttribute("date2", dates);

But it's giving me some wierd negative numbers, that I cannot make sense off.

d1 is always greater than d2 as it is the current time. so it should be d1.getTime() - d2.getTime() — Raghu K Nair, Apr 10 '16 at 22:56

score 1 · Accepted Answer · answered Apr 10 '16 at 22:41

it's giving me some wierd negative numbers

d2 is going to be before d1:

d2 was "now" the last time the method was called in this session
d1 is "now" this time the method was called.

As such, d2.getTime() < d1.getTime().

Reverse the order of the subtraction.

Measure the time it takes for Java class to run

1 Answers1