Java基础 小练习——统计各种文件的数量

public static void main(String[] args) {
    File f = new File("E:\\Java基础资料\\哈哈");
    HashMap<String, Integer> count = getCount(f);
    StringBuilder sb = new StringBuilder();
    for (Map.Entry<String, Integer> entry : count.entrySet()) {
        sb.append(entry.getKey()).append(":").append(entry.getValue()).append("个\n");
    }
    System.out.println(sb);
}

public static HashMap<String, Integer> getCount(File f) {
    HashMap<String, Integer> hm = new HashMap<>();
    for (File file : f.listFiles()) {
        if (file.isFile()) {
            String[] strings = file.getName().split("\\.");
            if(hm.containsKey(strings[strings.length - 1]))
                hm.put(strings[strings.length - 1], hm.get(strings[strings.length - 1]) + 1);
            else
                hm.put(strings[strings.length - 1], 1);
        } else {
            HashMap<String, Integer> hashMap = getCount(file);
            Set<Map.Entry<String, Integer>> entries = hashMap.entrySet();
            for (Map.Entry<String, Integer> entry : entries) {
                if(hm.containsKey(entry.getKey()))
                    hm.put(entry.getKey(), hm.get(entry.getKey()) + entry.getValue());
                else
                    hm.put(entry.getKey(), entry.getValue());
            }
        }
    }
    return hm;
}