public static void main(String[] args)
      throws IOException {
    //举个读取一本小说的例子
        String file="src\\book.txt";
        Map<Character,Integer> map=
                        countAll(file,"GBK");
        int all=0;
        Collection<Integer> values=map.values();
        
        for(int n:values){
            all+=n;
        }
        List<Entry<Character,Integer>> list=//像这里使用Map.Entry内部类，类似的应该怎么理解，运用？？？
            new ArrayList<Entry<Character,Integer>>(
                    map.entrySet());    
        Collections.sort(list,new 
                Comparator<Entry<Character,Integer>>(){
            private int dir=-1;
            public int compare(Entry<Character,Integer> o1,
                    Entry<Character,Integer> o2) {
                return dir*(o1.getValue()-o2.getValue());
            }
        });
        for(int i=0;i<10;i++){
            Entry<Character,Integer> entry=list.get(i);
            char ch=entry.getKey();
            int n=entry.getValue();
            System.out.println(
                    ch+":"+n+"个  "+((double)n/all)*100);    
        }
        System.out.println("不重复字数）："+map.size());
        System.out.println("文字总数："+all);
    }
    public static Map<Character,Integer> countAll(
            String file,String encoding)
             throws IOException {
        InputStreamReader in=
           new InputStreamReader(
             new BufferedInputStream(
              new FileInputStream(file)),encoding);
        Set<Character> set=
                new HashSet<Character>();
        set.add(',');
        set.add('　');
        set.add('，');
        set.add('。');
        set.add('：');
        set.add(':');
        //set.add(':');
        set.add('\n');
        set.add('\r');
        
        Map<Character,Integer> map=
                new HashMap<Character,Integer>();
        int c;
        int i=0;
        while((c=in.read())!=-1){
            char ch=(char)c;
            if(set.contains(ch)){//忽略掉回车换行，标点符号那些
                System.out.println(i++);
                continue;
            }
            Integer n=map.get(ch);
            map.put(ch, n==null? 1:n+1);
        }
        
        in.close();
        return map;
    }
}