Java/Timing

If you want an extremely detailed picture of how much time you're spending in the various parts of your code, you can use a profiler: see Java/Profiling

Basic Timing in Java: Builtin Methods

If you just want to see how much time a piece of code takes to execute, you can use Java's built in time functionality:

long start = System.nanoTime();
doStuff();
long end = System.nanoTime();
long duration = end - start;
System.out.printf("Elapsed time: %03f s\n", duration/1E9);

Timing Snippets of Code

Can make a Stopwatch class that does the following:

• Constructor creates a new "start" variable - the stopwatch class measures time starting at its own creation
• Can call elapsed() method to get elapsed seconds

Via http://introcs.cs.princeton.edu/java/32class/Stopwatch.java.html

public class Stopwatch {
    public Stopwatch() { 
        this.start = System.currentTimeMillis();
    }
    public double elapsed() {
        this.end = System.currentTimeMillis();
        return (end-start)/1000.0;
    }
}

Comparing Hombrew Data Containers to Java Collections API

In the Java repository at http://git.charlesreid1.com/cs/java in the lists/linked-lists folder (https://charlesreid1.com:3000/cs/java/src/master/lists/linked-lists), there is a timing script (https://charlesreid1.com:3000/cs/java/src/master/lists/linked-lists/Timing.java) that demonstrates a simple comparison of the built-in linked list type to a trimmed down generic TLinkedList type (https://charlesreid1.com:3000/cs/java/src/master/lists/linked-lists/TLinkedList.java).