What is the difference between a URL, a URI, and a URN?

What is the difference between a URL, a URI, and a URN?

Which characters make a URL invalid? Are these valid URLs? example.com/file[/].html http://example.com/file[/].html

We are moving from Java 8 to Java 11, and thus, from Spring Boot 1.5.6 to 2.1.2. We noticed, that when using RestTemplate, the '+' sign is not encoded to '%2B' anymore (changes by SPR-14828). This ...

I believe the definition and implementation of Java's URI.resolve method is incompatible with RFC 3986 section 5.2.2. I understand that the Java API defines how that method works, and if it were ch...

I'm building a JS library which has a requirement of looking at form[action] and a[href] values and resolving them into absolute URLs. For example, I'm on http://a/b/c/d;p?q and encounter an href v...

The doc of URLComponents.init(url:resolvingAgainstBaseURL:) says: Returns the initialized URL components object, or nil if the URL could not be parsed. Knowing that: Swift URL/NSURL is for URLs ...

See: https://www.rfc-editor.org/rfc/rfc3986#section-3 And: https://www.rfc-editor.org/rfc/rfc3986#section-3.3 The origin of "abempty" is mysterious to me, and a quick search didn't turn u...

I'd like to use , in URL querystring value but it is reserved character. However, we can see many e-commerce sites give comma-galore querystring urls in these days. What do we consider when we use...

The RFC 3986 URI: Generic Syntax specification lists a semicolon as a reserved (sub-delim) character: reserved = gen-delims / sub-delims gen-delims = ":" / "/" / "?" ...

is there a class to encode a generic String following the RFC 3986 specification? That is: "hello world" => "hello%20world" Not (RFC 1738): "hello+world" Thanks

TL;TR: Is (first) question mark in URL part of query or is is just a separator followed by query? The RFC 1738, section 3.3, suggests that the "?" (question mark) is not part of the query...

RFC 3986 specifies that the host component of a URI is 'case insensitive'. However, it doesn't specify what 'case insensitive' means in terms of UCS or UTF-8 characters. Examples given in the RFC (...

Assume an absolute http or https URL. I'm looking for an "official" or generally accepted name for the part of the URL that comes before the path. http://foo:[email protected]:8042/...

According to RFC 3986 the following characters are reserved and need to be percent-encoded in order to be used in a URI other than as their reserved uses: :/?#[]@!$&'()*+,;= Furthermore it spe...

When the URL http:///example.org is opened in Firefox or webkit-based browsers, it opens http://example.org. I wonder if this is a valid behavior, i.e. if the extra slash should be stripped and exa...

I have a question regarding URLs: I've read the RFC 3986 and still have a question about one URL: If a URI contains an authority component, then the path component must either be empty or begi...

First, some quick background... As part of an integration with a third party vendor, I have a C# .Net web application that receives a URL with a bunch of information in the query string. That URL i...

I need to generate a href to a URI. All easy with the exception when it comes to reserved characters which need percent-encoding, e.g. link to /some/path;element should appear as <a href="/some/...

I tried to find this in the relevant RFC, IETF RFC 3986, but couldn't figure it. Do URIs for HTTP allow Unicode, or non-ASCII of any kind? Can you please cite the section and the RFC that supports ...