Java 中 RandomAccessFile 类读取 txt 中数字

public static void readAccess() throws Exception {
    
    String filename = "D:/file_sum/2.txt";
    RandomAccessFile raf = new RandomAccessFile(filename, "rw");
    int len = 0;
    int seek = 0;
    int index = 0;
    while ((len = raf.read()) != -1) {
        char ch = (char) len;
        if (ch >= '0' && ch <= '9') {
            index ++;
        }

        if (ch == ' ') {
            raf.seek(seek);
            byte[] buff = new byte[index + 1];
            raf.read(buff, 0, buff.length);
            System.out.println(new String(buff).trim());
            seek += (index + 1);
            index = 0;
        }
    }

    if (index > 0) {
        raf.seek(seek);
        byte[] buff = new byte[index + 1];
        raf.read(buff, 0, buff.length);
        System.out.println(new String(buff).trim());
    }

    raf.close();
}

 输出结果：