Hi, I'm working with a REST API which returns a Link entity header to indicate "rel" links (previous, next, etc) for pagination over more results than are returned in a single call. In their docs they specifically reference this very outdated (and non-standard) spec [1], but it seems to be quite similar to the more current RFC 5988 [2].
The individual URI values in the Link header value contain query parameters. Here is the HC library wire trace of the entire header: 2016-03-10 22:36:31.354 [DEBUG] : org.apache.http.wire: http-outgoing-0 << "Link: <https://georgetown.test.instructure.com/api/v1/accounts/self/users?page=1&per_page=10>; rel="current",<https://georgetown.test.instructure.com/api/v1/accounts/self/users?page=2&per_page=10>; rel="next",<https://georgetown.test.instructure.com/api/v1/accounts/self/users?page=1&per_page=10>; rel="first",<https://georgetown.test.instructure.com/api/v1/accounts/self/users?page=559&per_page=10>; rel="last"[\r][\n]" When I attempt to extract this header from the HttpResponse and display the individual element values using code similar to: Header linkHeader = httpResponse.getFirstHeader("Link"); for (HeaderElement element : linkHeader.getElements()) { System.out.println("Saw HeaderElement: " + element.toString()); System.out.println("HeaderElement name: " + element.getName()); System.out.println("HeaderElement value: " + element.getValue()); } I'm seeing output for example: Saw HeaderElement: <https://georgetown.test.instructure.com/api/v1/accounts/self/users?page=1&per_page=10>; rel=current HeaderElement name: <https://georgetown.test.instructure.com/api/v1/accounts/self/users?page HeaderElement value: 1&per_page=10> So, it's splitting on the first '=' character to determine the element name vs value, which looks odd. And there doesn't seem to be a way in the API to get the value of the HeaderElement minus the parameters. Is this: 1) A bug in HttpClient's HeaderElement parsing? 2) A mistake on the part of the server sending these particular URL values (i.e. perhaps should be encoded in some way)? 3) Neither: Perhaps given knowledge of the specific header syntax and semantics, the name/value API is not appropriate for it, and I need to handle these values manually by for example: A) Stitching the URI back together manually as the name + "=" + value B) Splitting the HeaderElement#toString() on the semi-colon #3 makes me nervous at the moment since I don't fully understand the issues at hand. I'm trying to read through relevant HTTP specs to better understand the nuance of the header value syntax. But I know there are people on the list who are knowledgeable on the specs and may have a quick answer, so wanted to pose the question in the meantime. Thanks, Brent [1] http://www.w3.org/Protocols/9707-link-header.html [2] https://tools.ietf.org/html/rfc5988
