java统计一个文本文件英文单词

package test;

import java.io.*;
import java.util.*;

public class wordCount2 {
    public  static void main(String[] args) throws IOException {
        File file = new File("/Users/jiachenglin/Desktop/HP7.txt");
        try (FileInputStream fis = new FileInputStream(file);
             InputStreamReader isr = new InputStreamReader(fis, "gbk");
             BufferedReader br = new BufferedReader(isr)) {
            String str;
            Map<String, Integer> map = new TreeMap<>();
            while ((str = br.readLine()) != null) {
                String[] words = str.split("[ ,.:;'!…\"{}()?\\[\\]]");
                for (int i = 0; i < words.length; i++) {
                    String key = words[i].toLowerCase().trim();

                    //添加单词
                    if (key.length() > 0 && Character.isLetter(key.charAt(0))) {
                        if (!map.containsKey(key))
                            map.put(key, 1);
                        else
                            map.put(key, map.get(key) + 1);
                    }
                }

            }
            //Set<Map.Entry<String, Integer>> entrySet = map.entrySet();
            List<Map.Entry<String, Integer>> entrys = new ArrayList<>(map.entrySet());
            Collections.sort(entrys, new myComparator());
            int flag=0;
            String[] a=new String[1000000];
            System.out.println("请输入要查看的单词数");
            Scanner s=new Scanner(System.in);
            flag=s.nextInt();
            int i=0;
                for (Map.Entry<String, Integer> entry : entrys) {
                    //输出单词和数目
                    a[i]=entry.getKey()+"  "+entry.getValue();//利用字符串数组将Map中的key与value组合
                    i++;
                }
                for(int j=0;j<flag;j++){
                    System.out.println(a[j]);
                }
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

}
class myComparator implements Comparator<Map.Entry> {
    public int compare(Map.Entry o1, Map.Entry o2) {
        return ((Integer) o2.getValue()).compareTo((Integer) o1.getValue());
    }
}