Java TreeMap use

Scene: 50 randomly generated number from 10 to 50. Then sequentially output frequency of occurrence of each number

The principle: use TreeMap, with the default sort order functionality

	public static void main(String[] args) {
		Map map  = new TreeMap();
		
		Random random = new Random();
		
		for(int i = 0; i < 50; i++){
			int number = random.nextInt(41) +10;
			Integer in = new Integer(number);
			if(map.get(in) == null){
				map.put(in, new Integer(1));
			}else {
				int value = ((Integer)map.get(in)).intValue();
				map.put(in, new Integer(value +1));
			}
		}
		
		Set set = map.keySet();
		Iterator iter = set.iterator();
		while (iter.hasNext()) {
			Integer key = (Integer)iter.next();
			Integer value = (Integer)map.get(key);
			System.out.println(key + "=" + value);
			
		}
	}