How to find time taken to run a Java program?

Question

I have a Java application that I've been working on and I just realized that the program has to return a value in less than a minute, but don't know how to find or display the time taken to run the program. How to find time taken to run a program?

Answer 1

You can compare times using System.nanoTime() . It will return the time in nanoseconds.

Returns the current value of the most precise available system timer, in nanoseconds.

You could use it like this:

long startTime = System.nanoTime();  // code  long endTime = System.nanoTime(); System.out.println("Took "+(endTime - startTime) + " ns");  

Usefull links:

• System.nanoTime()

Answer 2

There is no built-in way to see for how long your program has been running. However, you could at the start of the program just store the current time, so that sometime later you can see how much time has elapsed.

public class MyProgram {     private static long startTime = System.currentTimeMillis();      public static void main(String[] args) {         // Do stuff...          // At the end         long endTime = System.currentTimeMillis();         System.out.println("It took " + (endTime - startTime) + " milliseconds");     } }