Testing if a file is open or not

Question

I know there are no standard Java mechanisms for testing if a file is open or not. Can anyone please tell me whether there is any libraries through which we can achieve this task, or some other ways,

This is my scenario, say I've open a docx file manually, when I try to upload that file itself its not getting uploaded since the file is opened, so if we tries to upload a file which is open outside it needs to display a message telling "The file is opened".

Do you want to know if the file is open in your process, or in *any* process? — Jonathon Reinhart, May 03 '14 at 07:55
can we find whether the file is open or not through file metadata, or header details — Alex Man, May 03 '14 at 07:57
whether it can be achieved through `client side`(by using some javascript or any) or `server side`(by using some java libraries) — Alex Man, May 03 '14 at 07:59
What do you mean by `file is opened`? are you talking about to open the file via code or from external tool? — Braj, May 03 '14 at 08:05
@Braj mean i want to know whether a file is open or not...... — Alex Man, May 03 '14 at 08:07
@Braj via code......if not possible via code, then through external libraries........ — Alex Man, May 03 '14 at 08:09
@Manu It means you have opened the file via code and now you want to know that is it already opened? — Braj, May 03 '14 at 08:11
@Braj no....this is my scenario say i've open a docx file manually, when i tries to upload that file itself its not getting uploaded since the file is opened, so if we tries to upload a file which is open outside it needs to display a message telling "The file is opened" — Alex Man, May 03 '14 at 08:14
The exception you get when trying to open it for upload is all you need. You don't need another piece of code. — user207421, May 03 '14 at 09:00

score 2 · Accepted Answer · edited May 23 '17 at 12:28

Using Java

If your client is a Java client (which you don't say in your question), you could try the following code from this answer:

Using the Apache Commons IO library...

boolean isFileUnlocked = false;
try {
    org.apache.commons.io.FileUtils.touch(yourFile);
    isFileUnlocked = true;
} catch (IOException e) {
    isFileUnlocked = false;
}

if(isFileUnlocked){
    // Do stuff you need to do with a file that is NOT locked.
} else {
    // Do stuff you need to do with a file that IS locked
}

BTW: This is the very first answer when you search for "java file is open" on Google.

Using JavaScript

However, I assume that you don't have a Java client, only a Java server and you want to upload a file via a webpage (so you have a HTML + JS client). I assume this, because you don't tell us.

JavaScript doesn't allow you to write to the disk since this would be a security issue (I think Chrome supports some kind of the JavaScript File API which allows you to write to the disk, but none of the other browsers). So you cannot test this via JavaScript.

In general

The general way to test if a file is open, would be to test if there is some lock on the file. But this would not guarantee that the file is not opened without a lock, but it should be sufficient.

Testing if a file is open or not

1 Answers1

Using Java

Using JavaScript

In general