How do I get the file extension of a file in Java?

Question

Just to be clear, I'm not looking for the MIME type.

Let's say I have the following input: /path/to/file/foo.txt

I'd like a way to break this input up, specifically into .txt for the extension. Is there any built-in way to do this in Java? I would like to avoid writing my own parser.

Answer 1

It's very easy, just apply FilenameUtils.getExtension from Apache Commons IO

Here is an example of how to use it (it's up to you whether you want to specify full path or just file name):

String ext1 = FilenameUtils.getExtension("/path/to/file/foo.txt"); // returns "txt"

String ext2 = FilenameUtils.getExtension("bar.exe"); // returns "exe"