Java 列出多个文件中单词的频率

我创建了一个程序，可以查看某个目录中的文本文件，然后继续列出该文件中的单词

例如，如果我的文本文件包含这个

你好，我叫约翰，你好，我的朋友

输出将显示

你好2

我的2

名字1

是1

约翰1

但是现在我希望我的程序搜索目录中的多个文本文件，并列出所有文本文件中出现的所有单词

这是我的程序，它将在一个文件中列出单词

import java.io.File;
import java.io.FileNotFoundException;
import java.util.HashMap;
import java.util.Scanner;

public class WordCountstackquestion implements Runnable {

    private String filename;

    public WordCountstackquestion(String filename) {
        this.filename = filename;
    }

    public void run() {
        int count = 0;
        try {
            HashMap<String, Integer> map = new HashMap<String, Integer>();
            Scanner in = new Scanner(new File(filename));

            while (in.hasNext()) {
                String word = in.next();

                if (map.containsKey(word))
                    map.put(word, map.get(word) + 1);
                else {
                    map.put(word, 1);
                }
                count++;

            }
            System.out.println(filename + " : " + count);

            for (String word : map.keySet()) {
                System.out.println(word + " " + map.get(word));

            }
        } catch (FileNotFoundException e) {
            System.out.println(filename + " was not found.");
        }
    }

}

我尝试使用一些在线资源来创建一个可以查看多个文件的方法。然而，我正在努力，似乎无法在我的程序中正确地实现它

每个文件都有一个工人类

 int count;

   @Override
   public void run()
   {
      count = 0;
      /* Count the words... */
      ...
      ++count;
      ...
   }

然后用这个方法来使用它们

public static void main(String args[]) throws InterruptedException
   {
      WordCount[] counters = new WordCount[args.length];
      for (int idx = 0; idx < args.length; ++idx) {
         counters[idx] = new WordCount(args[idx]);
         counters[idx].start();
      }
      int total = 0;
      for (WordCount counter : counters) {
        counter.join();
        total += counter.count;
      }
      System.out.println("Total: " + total);
   }

publicstaticvoidmain（字符串args[]）抛出中断异常
{
WordCount[]计数器=新的WordCount[args.length]；
对于（int idx=0；idx

我假设所有这些文件都位于同一个目录中。您可以这样做：

public void run() {
    // Replace the link to your filename variable
    File f = new File("link/to/folder/here");
    // Check if file is a directory (always do this if you are going to use listFiles()
    if (f.isDirectory()) {
        // I've moved to scanner object outside the code in order to prevent mass creation of an object
        Scanner in = null;
        // Lists all files in a directory
        // You could also use a for loop, but I prefer enchanced for loops
        for (File file : f.listFiles()) {
            // Everything here is your old code, utilizing a new file (now named "f" instead of "filename"
            int count = 0;
            try {
                HashMap<String, Integer> map = new HashMap<String, Integer>();
                in = new Scanner(f);

                while (in.hasNext()) {
                    String word = in.next();

                    if (map.containsKey(word))
                        map.put(word, map.get(word) + 1);
                    else {
                        map.put(word, 1);
                    }
                    count++;

                }
                System.out.println(f + " : " + count);

                for (String word : map.keySet()) {
                    System.out.println(word + " " + map.get(word));

                }
            } catch (FileNotFoundException e) {
                System.out.println(file + " was not found.");
            }
        }
        // Once done with the scanner, close it (I didn't see it in your code, so including it now)
        in.close();
    }
}

---

所以，问题是如何处理多个文件？您的程序当前输出什么？如果使用多线程，请不要直接访问变量。创建一个名为getCount（）的方法并添加同步修饰符。我的程序当前将只输出单个文件中的单词列表，我希望能够执行多个文件。感谢您的帮助，但是，当我疲于实现您的代码时，我的程序将终止，而不输出任何内容？我所做的只是将我的WordCountstackquestion类中的run方法更改为您的，然后运行我的Mainstackquestion类。为什么什么都不输出，程序就终止了？提前谢谢你的帮助！我查看了它，在方法中调用了“f”变量而不是“file”变量。说明您不应该复制和粘贴代码，而是应该了解它的工作原理并自己实现（就像重新编码一样）。

public void run() {
    // Replace the link to your filename variable
    File f = new File("link/to/folder/here");
    // Check if file is a directory (always do this if you are going to use listFiles()
    if (f.isDirectory()) {
        // I've moved to scanner object outside the code in order to prevent mass creation of an object
        Scanner in = null;
        // Lists all files in a directory
        // You could also use a for loop, but I prefer enchanced for loops
        for (File file : f.listFiles()) {
            // Everything here is your old code, utilizing a new file (now named "f" instead of "filename"
            int count = 0;
            try {
                HashMap<String, Integer> map = new HashMap<String, Integer>();
                in = new Scanner(f);

                while (in.hasNext()) {
                    String word = in.next();

                    if (map.containsKey(word))
                        map.put(word, map.get(word) + 1);
                    else {
                        map.put(word, 1);
                    }
                    count++;

                }
                System.out.println(f + " : " + count);

                for (String word : map.keySet()) {
                    System.out.println(word + " " + map.get(word));

                }
            } catch (FileNotFoundException e) {
                System.out.println(file + " was not found.");
            }
        }
        // Once done with the scanner, close it (I didn't see it in your code, so including it now)
        in.close();
    }
}

for(String s : arraylist){
    File f = new File(s);
}