How to create and work with a file anywhere if there is no permission to create a file in the current directory?

Question

I need to create a file and use the path to that file in the application. The problem is that there is no permission to create a file in the current directory.

I am testing my application and my current directory is /opt/development/appX/bin

I can not create a file in the bin directory. I can change the directory to some other directory where I have the permission, create the file there and use it, but this is because I know the directory structure of my system.

What if I do not know the structure of the system? It could be Linux/Windows, directory names could differ. Is it possible to find a place in the system, create a file there, use it and then delete when done? I need some Java code to allow me to create a file anywhere so that I could use its path. Is there a correct way to do that?

Interrogate the file system for suitable folder candidates. Java has ample facilities for doing this. Start here: https://docs.oracle.com/javase/7/docs/api/java/io/File.html — Robert Harvey, Aug 17 '21 at 14:48
Then, look [here](https://stackoverflow.com/questions/6231779) — Robert Harvey, Aug 17 '21 at 14:55
@RobertHarvey thank you for the comment, do you mean listRoots() method for that? And then check the permission of all folders one by one? — FalseScience, Aug 17 '21 at 15:05
Then use [the other post](https://stackoverflow.com/questions/6231779) to check each folder's write permissions. — Robert Harvey, Aug 17 '21 at 15:07
in that post they create a file in some directory and then check the subdirectories. I can not know for sure if I can create a file anywhere. — FalseScience, Aug 17 '21 at 15:15
Oh, Files.walk() method could help, I will try that, thank you — FalseScience, Aug 17 '21 at 15:17
Would a temporary file work? Do you need to keep it after the JVM exits, or just briefly while performing some process? https://mkyong.com/java/how-to-create-temporary-file-in-java/ — Tim Moore, Aug 18 '21 at 07:00
@g00se Unfortunately there are no write permissions on user.home — FalseScience, Aug 18 '21 at 10:11
Then something is very wrong. A user home directory with no write permission would be useless. In fact, I'm not sure if it's possible — g00se, Aug 18 '21 at 10:30

How to create and work with a file anywhere if there is no permission to create a file in the current directory?

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