NIO2 Path Symbols Java

Question

If I created a two paths such as:

 Path path3 = Paths.get("E:\\data");
 Path path4 = Paths.get("E:\\user\\home");

And then make a new Path(relativePath) by using the relativize() method on the two paths, creating: "..\user\home" does the path symbol(..) in this case refer to "data" or does it just indicate a relative path?

 Path relativePath = path3.relativize(path4);
 // ..\user\home <- output

So my Question is, what does the Path symbol (..) represent?

• deHaar: How exactly have you used relativize() on the two paths and created "..\user\home"? What't the output if you use toAbsolutePath().toString() on the resulting path?
• Progman: Does this answer your question? What do the dots mean in relative file path?
• LuCio: The JavaDoc of Path.relativize(Path other) (link) shows an example: if this path is "/a/b" and the given path is "/a/x" then the resulting relative path may be "../x". The relative path from "a/b" to "/a/x" is to go back to the parent folder ("..") and there to to go into the the target folder "x".

Answer 1

The relativize method needs two inputs but doesn't "secretly" encode the base path into it's output, so your relativePath has to be applied to another base path to actually access a path on disk.

But you can apply it to a different base path, e.g. if you want to sync two folder structures below two different base paths.

tl;dr: it just indicates a relative path.

But take care with your path separator: if you hardcode that into your path strings like in your example, it will fail on other systems. Better split up the individual parts in extra strings like this:

Path path4 = Paths.get("E:", "user", "home");