Spring REST URL Encoding Scheme: %20 or + Which one?

Question

I made a Spring REST application where you can perform CRUD operations based on HTTP methods of POST, PUT, GET, DELETE. I have the typical URI template of

http://host/root/{id}/{name}/{address} and etc.

We have a client who is accessing this REST service. Apparently they are sending parameters for multi-word name and address in the following form:

http://host/root/11/John+Smith/10+Las+Vegas+USA

They are using the HTML encoding scheme based on application/x-www-form-urlencoded type. According to the article in Wikipedia

The application/x-www-form-urlencoded type

The encoding used by default is based on a very early version of the general URI percent-encoding rules, with a number of modifications such as newline normalization and replacing spaces with "+" instead of "%20". - http://en.wikipedia.org/wiki/Percent-encoding

However it appears the standard URL encoding scheme is to use %20 in replacing spaces in URI templates. Which one is correct?

My Spring REST automatically converts %20 to spaces. It's interpreted correctly. I'm using Spring 3.0.4. When + is met by my REST service, it's accepted as is. Of course when I put validation to exclude +, it is indeed excluded as expected.

Am I within standards or are there such double standards? Or is the client using an ancient scheme?

Answer 1

The point is that application/x-www-form-urlencoded can be used only in request parameters, whereas percent encoding is also supported in a path.

So,

http://host/root/11/?name=John+Smith&address=10+Las+Vegas+USA

is fine and will be properly decoded by Spring MVC, but

http://host/root/11/John+Smith/10+Las+Vegas+USA

is wrong and Spring MVC doesn't decode it, because the following form should be used instead:

http://host/root/11/John%20Smith/10%20Las%20Vegas%20USA