pedido de árboles en Java

Set<String> ts = new TreeSet<String>();
	String[] v = {"1", "3", "1", "2"};

	for(int i=0; i< v.length; i++) 
	{
		ts.add(v[i]);
	}

	Iterator it = (Iterator) ts.iterator();

	while(it.nextInt())
	{
		System.out.println(it.next()+" ");
	}

}
Grieving Guanaco