Jit Example

JitExample.java

public class JitExample {

    public static void main(final String[] args) {

        new JitExample();
    }

    public JitExample() {

        final long oneStart = System.nanoTime();
        for (int i = 0; i < 1000; i++) {
            final StringBuffer sb = new StringBuffer();
            for (int j = 0; j < i; j++) {
                sb.append(j);
            }
            System.out.println(sb.toString().length());
        }
        final long oneDuration = System.nanoTime() - oneStart;

        final long twoStart = System.nanoTime();
        for (int i = 0; i < 1000; i++) {
            System.out.println(calculate(i));
        }
        final long twoDuration = System.nanoTime() - twoStart;

        final long threeStart = System.nanoTime();
        for (int i = 0; i < 1000; i++) {
            final StringBuffer sb = new StringBuffer();
            for (int j = 0; j < i; j++) {
                sb.append(j);
            }
            System.out.println(sb.toString().length());
        }
        final long threeDuration = System.nanoTime() - threeStart;

        System.out.println("oneDuration  =" + oneDuration);
        System.out.println("twoDuration  =" + twoDuration);
        System.out.println("threeDuration=" + threeDuration);
    }

    public int calculate(int i) {
        final StringBuffer sb = new StringBuffer();
        for (int j = 0; j < i; j++) {
            sb.append(j);
        }
        return sb.toString().length();
    }

}

output

oneDuration  =62671053
twoDuration  =37920883
threeDuration=47378592