你实现它如下：

1. 打开使用 RandomAccessFile


2. 寻找上次文件结尾的位置。 （如果这是第一次，请寻找文件的开头。）


3. 阅读，直至到达新的文件结尾。


4. 记录文件结尾的位置。


5. 关闭 RandomAccessFile

1. Open the using RandomAccessFile
2. Seek to where the end-of-file was last time. (If this is the first time, seek to the start of the file.)
3. Read until you reach the new end-of-file.
4. Record where the end-of-file is.
5. Close the RandomAccessFile

将位置记录为距文件开头的字节偏移量，并使用相同的值进行搜索。

Record the position as a byte offset from the start of the file, and use the same value for seeking.

您可以修改上述内容以重复使用 RandomAccessFile 对象，而不是每次都打开/关闭它。

You can modify the above to reuse the RandomAccessFile object rather than opening / closing it each time.

UPDATE - RandomAccessFile 的javadoc是这里。寻找 seek 和 getFilePointer 方法。

UPDATE - The javadocs for RandomAccessFile are here. Look for the seek and getFilePointer methods.