NULL Value in Java

import java.lang.reflect.Field;
import javax.swing.JOptionPane;
import sun.misc.Unsafe;

public class Testing {
    public static void main(String[] args) throws Exception {
        Integer varInt = 147147147;
        System.out.println(Long.toHexString(Addresser.addressOf(varInt)));
        JOptionPane.showMessageDialog(null, "1st Change");

        varInt = 258258258;
        System.out.println(Long.toHexString(Addresser.addressOf(varInt)));
        JOptionPane.showMessageDialog(null, "2nd Change");

        varInt = null;
        System.out.println(Long.toHexString(Addresser.addressOf(varInt)));
        JOptionPane.showMessageDialog(null, "Changed to null");

        varInt = 639639639;
        System.out.println(Long.toHexString(Addresser.addressOf(varInt)));
        JOptionPane.showMessageDialog(null, "4th Change");
    }
}

class Addresser {
    @SuppressWarnings("restriction")
    private static Unsafe unsafe;

    static {
        try {
            Field field = Unsafe.class.getDeclaredField("theUnsafe");
            field.setAccessible(true);
            unsafe = (Unsafe) field.get(null);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static long addressOf(Object o) throws Exception {
        Object[] array = new Object[] { o };

        long baseOffset = unsafe.arrayBaseOffset(Object[].class);
        int addressSize = unsafe.addressSize();
        long objectAddress;
        switch (addressSize) {
        case 4:
            objectAddress = unsafe.getInt(array, baseOffset);
            break;
        case 8:
            objectAddress = unsafe.getLong(array, baseOffset);
            break;
        default:
            throw new Error("unsupported address size: " + addressSize);
        }

        return (objectAddress);
    }

    public static void main(String... args) throws Exception {
        Object mine = "Hi there".toCharArray();
        long address = addressOf(mine);
        System.out.println("Addess: " + address);

        // Verify address works - should see the characters in the array in the output
        printBytes(address, 27);

    }

    public static void printBytes(long objectAddress, int num) {
        for (long i = 0; i < num; i++) {
            int cur = unsafe.getByte(objectAddress + i);
            System.out.print((char) cur);
        }
        System.out.println();
    }
}