Java Database Connectivity (JDBC)

I believe there might an ambiguity when using IPv6 IP address
format with JDBC connection address.

A common format for the connection url is:

jdbc:subprotocol:subname

Where:

subprotocol = <some name>

subname = //<{IP Address|Machine Name}[:port]>/<database name>

Example:
jdbc:sql:t9://130.168.200.30:1433/database1

An IPv6 has the format

x:x:x:x:x:x:x:x

where the 'x's are the hexadecimal values of the
eight 16-bit pieces of the address. This is the
full form. For example,

1:2:0:0:5:6

The IPv6 format also allows an abbreviation version where 0's are
replaced with "::". So, the above address could also be written
as:

1:2::5:6

An optional port number can be added. For example,

1:2:0:0:5:6:8888

or as the following if using the abbreviation version of IPv6

1:2::5:6:8888

While decoding this version of the address, an ambiguity arises.
Does the address expand to

1:2:0:5:6:8888 // no optional port number

or

1:2:0:0:5:6:8888 // contains the optional port number.

Is this correct? If so, how are vendors dealing with this?

Thanks,

.........Ken