Java实现大量文件中读取关键字

package searchWorld;

// 实现从大量文件中超过一百次的关键字

import java.io.File;
import java.io.IOException;
import java.util.Scanner;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.LongAdder;

public class BlockingQueueTest {
    // blockqueue len = 10
    private static final int FILE_QUEUE_SIZE = 10;
    private static final int SEARCH_THREADS = 1000;
    private static final File DUMMY = new File("");
    private static BlockingQueue<File> queue = new ArrayBlockingQueue<>(FILE_QUEUE_SIZE);
    private static ConcurrentHashMap<String,LongAdder> hashMap = new ConcurrentHashMap<>();
    public static void main(String[] args) {
        // input a dir

        try(Scanner in = new Scanner(System.in)) {
            System.out.println("请输入一个目录");
            String directory = in.nextLine();
            Runnable enumerator = () -> {
                try {
                    enumrate(new File(directory));

                    // add a last file DUMMY as bool
                    queue.put(DUMMY);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            };
            new Thread(enumerator).start();
            for (int i = 1; i <=SEARCH_THREADS ; i++) {
                Runnable search = ()->{
                  boolean done = false;
                  while (!done){
                      try {
                          File file = queue.take();
                          if(file == DUMMY){
                              queue.put(file);
                              done = true;
                          }else search(file);
                          done = true;
                      } catch (InterruptedException e) {
                          e.printStackTrace();
                      } catch (IOException e) {
                          e.printStackTrace();
                      }
                  }
                };
                new Thread(search).start();
            }

            while (Thread.activeCount() == 1){
                getMoreHundredWord();
            }
        }


    }

    // put all file to a blockqueue
    public static void enumrate(File directory) throws InterruptedException{
        File[] files = directory.listFiles();
        for (File file: files
             ) {
            if(file.isDirectory()) enumrate(file);
            else {queue.put(file);}
        }
    }

    // search keywords
    public static void search(File file) throws IOException{
        try(Scanner in = new Scanner(file,"UTF-8")) {
            while (in.hasNextLine()){
                String line = in.nextLine();
                // regular get word
                line =line.replaceAll("[^a-zA-Z\\s+]", "");
                String[] words =line.split("[\\s+,\\.\n]");
                System.out.println(words);
                for(String word:words) {
                    // automic update
                    hashMap.putIfAbsent(word, new LongAdder());
                    hashMap.get(word).increment();
                }
            }
        }

    }

    // get > 100 words
    public static void getMoreHundredWord(){
        hashMap.forEach(1,
                (k, v) -> {
                if (v.longValue() > new Long(100).longValue())
                System.out.println(k + " -> " + v);
        });

    }
}