How can I tell if a file was renamed?

Question

I have a program monitors log file changes. The program uses a FileInputStream to keep reading from the file. In the mean while, the log file might be rotated: the old log file is renamed and new log entries are written into a new file.

How can my program determines the file was rename so that it switch to read on the new log file?

Answer 1

According to this question, JNotify sseems to be the perfect solution to your problem :

JNotify is a java library that allow java application to listen to file system events, such as:

File created

File modified

File renamed

File deleted

Answer 2

也许您可以根据自己的需要观看文件系统并进行更改。

Answer 3

The easiest way I can think of is simply to poll for the file size every 5 seconds or something like that.

If the file you are reading from was renamed and a new one was created, then your polling will show a sudden decrease in size. You can then recreate you FileinputStream accordingly.