Source code for example showing Autoboxing and Unboxing

SlowAutoboxing.java

/*
 * Author : Yashwant Golecha (ygolecha@gmail.com) * 
 * http://idlebrains.org/tutorials/java-tutorials/primitives-boxed-primitives-autoboxing-unboxing/

*/

package oracle.apps;

import java.util.Comparator;
import java.util.Date;

public class SlowAutoboxing {
    public SlowAutoboxing() {
        super();
    }

    public static void main(String[] args) {
        autoBoxingInLopp();
        withoutAutoBoxingInLopp();
        autoBoxingInLopp2();
        // Uncomment following line to see NPE.
        //shocking();
        
//        compare();
//        improvedCompare();
    }
    
    public static void autoBoxingInLopp() {
        Date startTime = new Date();
        Long sum = 0L;
        for (long i = 0; i < Integer.MAX_VALUE; i++) {
            sum += i;
        }
        System.out.println("Sum : " + sum);
        Date endTime = new Date();
        long timeDiff = endTime.getTime() - startTime.getTime();
        System.out.println("With Autoboxing in loop : " + timeDiff  + " ms");
    }
    
    public static void withoutAutoBoxingInLopp() {
        Date startTime = new Date();
        long sum = 0L;
        for (long i = 0; i < Integer.MAX_VALUE; i++) {
            sum += i;
        }
        System.out.println("Sum : " + sum);
        Date endTime = new Date();
        long timeDiff = endTime.getTime() - startTime.getTime();
        System.out.println("Without Autoboxing in loop : " + timeDiff  + " ms");
    }
    
    public static void autoBoxingInLopp2() {
        Date startTime = new Date();
        Long sum = 0L;
        for (Long i = 0L; i < Integer.MAX_VALUE; i++) {
            sum += i;
        }
        System.out.println("Sum : " + sum);
        Date endTime = new Date();
        long timeDiff = endTime.getTime() - startTime.getTime();
        System.out.println("With Autoboxing in loop : " + timeDiff  + " ms");
    }
    
    static Integer i;               
    public static void shocking() {
        if(i == 1)
            System.out.println("Shocking !!");
        else
            System.out.println("Expected !!");
    }
    
    public static void compare() {
        Comparator<Integer> naturalOrder = new Comparator<Integer>() {
            public int compare(Integer first, Integer second) {
                return first < second ? -1 : (first == second ? 0 : 1);
            }
        };        
        Integer i = new Integer(21);
        Integer j = new Integer(21);
        System.out.println(naturalOrder.compare(i, j));
    }
    
    public static void improvedCompare() {
        Comparator<Integer> naturalOrder = new Comparator<Integer>() {
            public int compare(Integer first, Integer second) {
                int f = first; int s = second;                
                return f < s ? -1 : (f == s ? 0 : 1);
            }
        };        
        Integer i = new Integer(21);
        Integer j = new Integer(21);
        System.out.println(naturalOrder.compare(i, j));
    }
                
}