统计字符串中每个元素出现的次数

private static void CountStr(String str) {
	// TODO Auto-generated method stub
	char[] array = str.toCharArray();
	HashMap<Character, Integer> hm = new HashMap<Character, Integer>();
	for(char c:array) {
		if(!hm.containsKey(c)) {
			hm.put(c, 1);
		}else {
			//	重复即覆盖
			hm.put(c, hm.get(c)+1);
		}
	}
	for(char key:hm.keySet()) {
			System.out.print(key + "" + hm.get(key));
		}
	}