Clarify path param (URI template) matching behavior of trailing '/' in incoming path

[glassfishrobot]

As mentioned in jsr356-experts:
http://java.net/projects/websocket-spec/lists/jsr356-experts/archive/2013-04/message/15

In the email http://java.net/projects/websocket-spec/lists/jsr356-experts/archive/2013-03/message/33
From: Danny Coward
Subject: Closing the gaps in the URI matching specification
Date: Mon, 18 Mar 2013 17:12:35 -0700

He gives a particular example ...

(snip)
suppose we have three endpoints and their paths:
endpoint A: /a/{var}/c
endpoint B: /a/b/c
endpoint C: /a/{var1}/{var2}
incoming URI: a/b/c matches B, not A or C, because an exact match is preferred.
incoming URI: a/d/c matches A with variable var=d, because like goldlocks, its just right
incoming URI: a/x/y/ matches C, with var1=x, var2=y
(/snip)

I have issue with In the last match of incoming path "a/x/y/" (note the trailing slash)
I feel this is a bad behavior of the matching.

A scenario to ponder this behavioral quirk.

endpoint A: "/a/{var}/c/"
endpoint B: "/a/b/c"
endpoint C: "/a/{var1}/{var2}"
endpoint D: "/a/{var1}/{var2}/{var3}"

What should the incoming path "/a/x/y/" match?
Is it endpoint C with ...
var1 = "x"
var2 = "y"
or is it endpoint D with ...
var1 = "x"
var2 = "y"
var3 = ""

I don't think it should match C as the incoming path has the trailing slash indicating another path segment.
Since we are calling this whole concept PathParam, I feel that this would keep us consistent as well.

[glassfishrobot]

@glassfishrobot Commented
Reported by joakimerdfelt

[glassfishrobot]

@glassfishrobot Commented
markt_asf said:
RFC3986 essentially says it is up to us how to handle trailing /.

I currently prefer the position that /a/b != /a/b/ and that /a/b/ does not match /a/{var}

This is closely aligned with how to handle //.

[glassfishrobot]

@glassfishrobot Commented
dannycoward said:
Yes I think /a/b != /a/b/, especially because some http servers in front of the websocket impl may find the difference significant.

[glassfishrobot]

@glassfishrobot Commented
This issue was imported from java.net JIRA WEBSOCKET_SPEC-195

[glassfishrobot]

• Issue Imported From: https://github.com/javaee/websocket-spec/issues/195
• Original Issue Raised By:@glassfishrobot
• Original Issue Assigned To: @pavelbucek

[markt-asf]

This is covered (arguably indirectly) in the current specification text where it states:

the paths do not match if they do
not have the same number of segments, using ’/’ as the separator

That means /a/b/ can't match /a/{var} as the number of segments differ. I'll add an explicit example to the documentation.