public void testIterator(){
		Set<Course> set = new HashSet<Course>();
		Iterator<Course> it = set.iterator();
		System.out.println("通过Iterator遍历");
		
		while(it.hasNext()){
//			System.out.println(it.hasNext());
//			System.out.println(".....");
			System.out.println(it.next());
		}
	}