public static void Swap(String s1, String s2) {
    String temp = s1;
    s1 = s2;
    s2 = temp;
}

private void swap(String a, String b) {
   try {
     Field value = String.class.get("value");
     value.setAccessible(true);    // this should be forbidden!!

     char[] temp = value.get(a);
     value.set(a, value.get(b));
     value.set(b, temp);           // Aaargh, please forgive me
   } catch(Exception e) {
     e.printStackTrace(e);
   }
 }

public class BubbleSort<E extends Comparable> {
	private E[] objArray; 

	.........

	public void sort() {
		if (objArray.length > 0) {
			for (int i = 0; i < objArray.length; i++)
				for (int j = i; j < objArray.length - 1; j++) {
					E o1 = objArray[j];
					E o2 = objArray[j + 1];
					
					if (o1.compareTo(o2) > 0) {
						RefObject<E> r1 = new RefObject<E>(objArray[j]);
						RefObject<E> r2 = new RefObject<E>(objArray[j + 1]);
						RefObject<E> r3 = new RefObject<E>(objArray[j]);
						
						r1.setArgvalue(r2.getArgvalue());
						r2.setArgvalue(r3.getArgvalue());
					}
				}
		}
	}
}

public final class RefObject<T>
{
    public T argvalue;
    
    public RefObject(T refarg) {
        argvalue = refarg;
    }

	public T getArgvalue() {
		return argvalue;
	}

	public void setArgvalue(T argvalue) {
		this.argvalue = argvalue;
	}
}