CODEWITHSUNDEEP
javafilebyte
Kel Varnsen
Kel Varnsen

Reputation: 354

Byte array to File object without saving to disk

I have a method that takes in a byte[] that came from Files.readAllBytes() in a different part of the code for either .txt or .docx files. I want to create a new File object from the bytes to later read contents from, without saving that file to disk. Is this possible? Or is there a better way to get the contents from the File bytes?

Upvotes: 3

Views: 12276

Answers (1)

rzwitserloot
rzwitserloot

Reputation: 103913

That's not how it works. a java.io.File object is a light wrapper: Check out the source code - it's got a String field that contains the path and that is all it has aside from some bookkeeping stuff.

It is not possible to represent arbitrary data with a java.io.File object. j.i.File objects represent literal files on disk and are not capable of representing anything else.

Files.readAllBytes gets you the contents from the bytes, that's.. why the method has that name.

The usual solution is that a method in some library that takes a File is overloaded; there will also be a method that takes a byte[], or, if that isn't around, a method that takes an InputStream (you can make an IS from a byte[] easily: new ByteArrayInputStream(byteArr) will do the job).

If the API you are using doesn't contain any such methods, it's a bad API and you should either find something else, or grit your teeth and accept that you're using a bad API, with all the workarounds that this implies, including having to save bytes to disk just to satisfy the asinine API.

But look first; I bet there is a byte[] and/or InputStream variant (or possibly URL or ByteBuffer or ByteStream or a few other more exotic variants).

Upvotes: 6

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