Java 7 zip file system provider doesn't seem to accept spaces in URI

I have been testing all possible variations and permutations, but I can't seem to construct a FileSystemProvider with the zip/jar scheme for a path (URI) that contains spaces. There is a very simplistic test case available at Oracle Docs. I took the liberty of modifying the example and just adding spaces to the URI, and it stops working. Snippet below:

import java.util.*;
import java.net.URI;
import java.nio.file.*;

public class Test {
    public static void main(String [] args) throws Throwable {
        Map<String, String> env = new HashMap<>(); 
        env.put("create", "true");
        URI uri = new URI("jar:file:/c:/dir%20with%20spaces/zipfstest.zip");
        Path dir = Paths.get("C:\\dir with spaces");
        if(Files.exists(dir) && Files.isDirectory(dir)) {
            try (FileSystem zipfs = FileSystems.newFileSystem(uri, env)) {}
        }
    }
}

When I execute this code (Windows, JDK7u2, both x32 and x64), I get the following exception:

java.lang.IllegalArgumentException: Illegal character in path at index 12: file:/c:/dir with spaces/zipfstest.zip
    at com.sun.nio.zipfs.ZipFileSystemProvider.uriToPath(ZipFileSystemProvider.java:87)
    at com.sun.nio.zipfs.ZipFileSystemProvider.newFileSystem(ZipFileSystemProvider.java:107)
    at java.nio.file.FileSystems.newFileSystem(FileSystems.java:322)
    at java.nio.file.FileSystems.newFileSystem(FileSystems.java:272)

If I use + instead of %20 as the space escape character, a different exception is thrown:

java.nio.file.NoSuchFileException: c:\dir+with+spaces\zipfstest.zip
    at sun.nio.fs.WindowsException.translateToIOException(WindowsException.java:79)
    at sun.nio.fs.WindowsException.rethrowAsIOException(WindowsException.java:97)
    at sun.nio.fs.WindowsException.rethrow