java 读取键盘输入到txt文件，统计每个单词出现的次数并输出

package javatest;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Scanner;
import java.util.Set;

public class Demo {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入 ：");
        String inputStr = scanner.nextLine();

        System.out.println("inputStr :  " + inputStr);
        File file = new File("D:/test/test01.txt");
        FileOutputStream fileOut;
        try {
            fileOut = new FileOutputStream(file);
            fileOut.write(inputStr.getBytes());
        } catch (FileNotFoundException e) {
            e.printStackTrace();

        } catch (IOException e) {

            e.printStackTrace();

        }

        String result = "";
        try {
            BufferedReader br = new BufferedReader(new FileReader(file));//构造一个BufferedReader类来读取文件
            String s = null;
            while ((s = br.readLine()) != null) {//使用readLine方法，一次读一行
                result = result + s + " ";
            }
            br.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
        System.out.println("---------------------------------------------");
        System.out.println(result);
        String[] arr = result.split(" ");

        System.out.println(Arrays.toString(arr));
        System.out.println(arr.length);

        Map<String, Integer> map = new HashMap<>();

        for (String str : arr) {
            Integer num = map.get(str);
            map.put(str, num == null ? 1 : num + 1);
        }
        Set set = map.entrySet();
        Iterator it = set.iterator();
        System.out.println("---------------------------------------------");

        System.out.println("方法一 ：");

        while (it.hasNext()) {
            Map.Entry<String, Integer> entry = (Map.Entry<String, Integer>) it.next();
            System.out.println("单词 " + entry.getKey() + " 出现次数 : " + entry.getValue());
        }
        System.out.println("---------------------------------------------");

        System.out.println("方法二 ：");

        Iterator it01 = map.keySet().iterator();
        while (it01.hasNext()) {
            Object key = it01.next();
            System.out.println("单词 " + key + " 出现次数 : " + map.get(key));

        }
    }
}
package javatest;

import java.io.BufferedReade