FULL PRODUCT VERSION :
java version "1.8.0_45"
Java(TM) SE Runtime Environment (build 1.8.0_45-b14)
Java HotSpot(TM) 64-Bit Server VM (build 25.45-b02, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
OS X Yosemite: Version 10.10.4 (14E46)

EXTRA RELEVANT SYSTEM CONFIGURATION :
I'm on a network with full support for IPv6.

A DESCRIPTION OF THE PROBLEM :
Opening a socket to an IPv6-only host results in a 'No Route to Host' exception when instantiating a socket with either a host name or an IP address.  I should note that I can ping the host, connect to the host with a web browser, and connect with sockets in other languages.    Opening a socket with other programming languages results in a successful socket connection (tested in python).  If instead of instantiating the socket with a hostname, i specify the IP address with the scope id of the interface appended (%4 for me on en0), the socket connects successfully and doesn't throw an exception.  

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
You might have to try this with several configurations.  For me this happens reliably on my wireless card (scope id %4), and works correctly on my wired card (scope id %13).

1.  Stage an host with only an IPv6 address on a network that supports IPv6.
2.  Instantiate a socket with the hostname of the target IPv6 host.
3.  If you're attempting this on the correct configuration, the socket will throw a 'No Route to Host' exception even if there is a route to the host.



EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The socket to connect successfully.  This is what happens on the same computer with python as well as web browsers (written in c, c++, and objective c).  Other languages can successfully connect.
ACTUAL -
The no route to host exception throws when I'm connected on my wireless adapter (scope id %4), but not when I'm connected on my wired adapter (scope id %13).  This was attempted on several other computers with identical configurations.  Reportedly, the socket successfully connected when a different user attempted this on java 1.6 after failing with an identical error message on the current version of java.

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
// This fails:

try {
	Socket s = new Socket("your:ipv6:add:ress:here:0:39:0", 443);
} catch (UnknownHostException e) {
	e.printStackTrace();
} catch (IOException e) {
	e.printStackTrace();
} 

---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
// this succeeds

try {
	Socket s = new Socket("your:ipv6:add:ress:here:0:39:0%4", 443);
} catch (UnknownHostException e) {
	e.printStackTrace();
} catch (IOException e) {
	e.printStackTrace();
}