String fileName = "D:/date.java.bak";         // String fileName = "D:/test.qqq";         String line;         int i = 0, j = 0, f = 0, k = 0;         try {             BufferedReader in = new BufferedReader(new FileReader(fileName));             line = in.readLine();             while (line != null) {                 // System.out.println(line);                 char c[] = line.toCharArray();                 for (int i1 = 0; i1 < c.length; i1++) {                     // 如果是字母                     if (Character.isLetter(c[i1]))                         i++;                     // 如果是数字                     else if (Character.isDigit(c[i1]))                         j++;                     // 是空格                     else if (Character.isWhitespace(c[i1]))                         f++;                 }                 line = in.readLine();                 k++;             }             in.close();             System.out                     .println("字母:" + i + ",数字:" + j + ",空格:" + f + ",行数:" + k);         } catch (IOException e) {             e.printStackTrace();         }