FileInputStream fis = null;
HashMap<Character, Integer> map = new HashMap<>();

while ((len = fis.read(b))!=-1){
// 獲得文件中的字符串
      s = new String(b, 0, len);
}

// 遍歷字符串得到每一個字符
 for (int i = 0; i < s.length() ; i++) {
     char c = s.charAt(i);
     // 判斷是否是字母
     if ( ((c>='a')&&(c<='z')) || ((c>='A')&&(c<='Z'))){
     // 將字母轉(zhuǎn)換為小寫
     char nc = Character.toLowerCase(c);
    // 判斷map集合中是否有該鍵
     if (map.containsKey(nc)){
     Integer num = map.get(nc);
     num++;
     map.put(nc,num);
  }else {
     map.put(nc,1);
    }
  }

  }

// 遍歷map集合得到數(shù)據(jù)
Set<Character> key = map.keySet();
  for (Character c : key) {
  Integer value = map.get(c);
  System.out.println("key="+c+"----"+"value="+value);
}

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

public class totalNum {
    public static void main(String[] args) throws IOException {
        // todo 統(tǒng)計字母出現(xiàn)的次數(shù)
        FileInputStream fis = null;
        String s = null;
        HashMap<Character, Integer> map = new HashMap<>();
        try {
            fis = new FileInputStream("E:\\JavaCode\\JavaSE\\Day8-25\\src\\a1\\a.txt");
            byte[] b = new byte[1024];
            int len = 0;

            while ((len = fis.read(b))!=-1){
                // 獲得文件中的字符串
                 s = new String(b, 0, len);
            }

            // 遍歷字符串得到每一個字符
            for (int i = 0; i < s.length() ; i++) {
                char c = s.charAt(i);
                // 判斷是否是字母
                if ( ((c>='a')&&(c<='z')) || ((c>='A')&&(c<='Z'))){
                    // 將字母轉(zhuǎn)換為小寫
                    char nc = Character.toLowerCase(c);
                    // 判斷map集合中是否有該鍵
                    if (map.containsKey(nc)){
                        Integer num = map.get(nc);
                        num++;
                        map.put(nc,num);
                    }else {
                        map.put(nc,1);
                    }
                }

            }

            // 遍歷map集合得到數(shù)據(jù)
            Set<Character> key = map.keySet();
            for (Character c : key) {
                Integer value = map.get(c);
                System.out.println("key="+c+"----"+"value="+value);
            }



        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            fis.close();
        }
    }
}