Add a means to convert a URI to a JimfsPath

There is no obvious way to convert a URI into a JimfsPath. Normally, one could use fs.provider().getPath(uri), but this is not implemented by JimfsFileSystemProvider; instead, it throws an exception stating:

This method should not be called directly; use Paths.get(URI) instead.

Which is funny, since on #12 @cgdecker (main contributor to the project?)

strongly recommends not using Paths.get

I would’ve used JimfsFileSystem.toPath(URI), but the entire class is set to the package-private access modifier (why the hell?).

[cgdecker]

@o2themar You’re getting that exception because you’re calling FileSystems.newFileSystem(URI, Map) with a URI with the scheme jimfs. That tells Jimfs to create a new Jimfs file system, not a zip file system, and the URI for a Jimfs file system isn’t allowed to have a path, query or fragment (because they don’t make sense in that context).

The scheme for a zip file system is jar:<underlying file system scheme>, so in the case of a file in a Jimfs file system, jar:jimfs. So your code would probably work if you just pass "jar:" + zipURI.getScheme() as the scheme for your new URI.

That said, you should be able to get a zip file system for a Jimfs path by just calling FileSystems.newFileSystem(Path, Map):

Path zipPath = pathFromJimfs;
Map<String, Object> env = new HashMap<>();
env.put("create", Boolean.toString(Files.notExists(outputZipAbsolutePath)));
env.put("encoding", "UTF-8");
FileSystem zipFileSystem = FileSystems.newFileSystem(zipPath, env);

[eyalroth]

@cgdecker I got to review this issue again with the recent activity, and I’m appalled at my previous behavior. I apologize for the demanding and combative tone. I really appreciate the work and effort you put into this!