采用二进制方式将一组对象写入文件,对象以固定长度写入，并用RandomAccessFile实现随机存取；以倒序的方式从文件中读出记录，并在控制台显示-Using a set of binary object written to the file, write to object to a fixed length, and use RandomAccessFile to achieve random access　in reverse order read from the file record, and the console display