java8 stream统计字符串中每个字母的个数

String str="qqqweaaaasdffg";
HashMap<String, Long> collect = Stream.of(str.split("")).collect(Collectors.groupingBy(Function.identity(), HashMap::new, Collectors.counting()));
collect.entrySet().forEach(e->{
    System.out.println(e.getKey()+"============"+e.getValue());
});