CODEWITHSUNDEEP
javafiledetectfile-watcher
JaffolasCage
JaffolasCage

Reputation: 31

Detect a file that will be modified

I have a large directory containing files that are modified by a seperate system at varying intervals. I am running a watcher on this directory to detect which files are modified.

I'm wondering if there is some sort of trigger that occurs when a file is accessed by the system for modification. If so, the following would apply:

Using Java, is it possible to detect which files are about to be modified and make a temporary backup before that happens?
Alternately, is it possible to compare the newly modified file against it's previous version?

In this scenario, it is impossible to make a back up of every file as the files are large and there are many of them.

Example:

I have four files:

a.xml
b.xml
c.xml
d.log

b.xml has a new section added.

Is it possible to copy the newly created section into d.log?

Upvotes: 2

Views: 623

Answers (3)

awd
awd

Reputation: 2322

No. you can not detect a file that will be modified. not until they come up with a highly accurate future predicting AI system.

your best approach would be to maintain a versioned backup of the the files. I would start with looking into some source code management system design considerations.

Upvotes: 1

Jitendra S.Tomar
Jitendra S.Tomar

Reputation: 53

I can think of one way which could be a possible solution to your problem. "Maintain a log file which tracks lastModified date of each files and you can verify which file has been modified by using your log file.

-- Jitendra

Upvotes: 3

Sid Mani
Sid Mani

Reputation: 369

How would you know if the files are about to be modified? The system handles all of the file IO. The only way you could do that is to have the program doing the modification trigger the backup, and then make the modifications. For comparison, it depends on what you want. If you want a line-by-line comparison, that should be fairly simple to do using Java's file IO classes. If you just want to check if they are the same or not, you can use a checksum on both files.

Upvotes: 1

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