What is the deal with Java's bizarre file protocol handling?
I mean on windows UNC path's get turned into 5 slashes, and I get why that happens, but on linux an absolute path gets turned into file:/local/path/to/file
Shouldn't that have three slashes?
I'm assuming the authors of Java aren't incompetent, so is there an explanation for why that's acceptable?
Let’s start with the documentation of the URI class:
A hierarchical URI is subject to further parsing according to the syntax
[scheme
:][//authority][path][?query][#fragment]
As you can see, the authority is optional. This is supported by the URI specification, section 3:
The scheme and path components are required, though the path may be empty (no characters). When authority is present, the path must either be empty or begin with a slash ("/") character. When authority is not present, the path cannot begin with two slash characters ("//").
A file: URI can have an authority separator, //, with an effectively empty authority after it, but it serves no purpose, so there is no harm in omitting it. It’s still a fully compliant URI.