Cannot show javadoc of core JDK classes on JDK 9+

[jumarko]

UPDATE 2: for now, there seem to be consistent issues with at least:

• cider-javadoc -> adds an extra "java.base" javadoc url path segment which leads to 404 NOT FOUND error
• cider-doc doesn't show proper javadoc for newer(?) JDK classes (e.g. java.lang.Module)

UPDATE: It must be something in my ./lein/profiles.clj - when I remove them it works. I'll try to find out what's causing that.

I can't display javadoc for core classes like java.lang.String even though JDK sources are available.

It works when I use JDK 8.
If I use anything more recent (tested with JDK 9 and 11) then it doesn't work.

Perhaps related to #2686

Expected behavior

When invoking cider-javadoc the javadoc for the String class should be displayed:

Actual behavior

Javadoc is not shown:

Steps to reproduce the problem

• set java version to JDK 11 (perhaps using jenv)
• run cider-jack-in
• type String into the REPL/buffer and try to show javadoc

Environment & Version information

CIDER version information

CIDER 0.22.0snapshot (package: 20190808.1659), nREPL 0.6.0
Clojure 1.10.1, Java 11.0.2

Lein/Boot version

lein -v
Leiningen 2.9.1 on Java 11.0.2 OpenJDK 64-Bit Server VM

Emacs version

25.3.1

Using Spacemacs

Operating system

Mac OS X 10.14.5

[bbatsov]

UPDATE: It must be something in my ./lein/profiles.clj - when I remove them it works. I'll try to find out what's causing that.

What's in your profiles? //cc @jeffvalk

[jumarko]

There are quite a few things in my profiles.clj although I commented out many of them yesterday. The current version is here: https://github.com/jumarko/clojure-experiments/blob/master/lein-profiles.clj.

Unfortunately, I'm now not so sure that it's completely caused by the presence of profiles.clj.
It seems that it works even when I'm using my current profiles.clj (at least on https://github.com/jumarko/lein-sample) for things like java.lang.String or java.lang.Number.
However, it doesn't seem to work for newer classes like java.lang.Module.

Moreover, the cider-javadoc seems to be broken for (at least) JDK 11.
clojure.java.javadoc/javadoc works without problems; e.g.

(javadoc String)
;;=> opens proper docs: https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/String.html

However, invoking cider-javadoc yields https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java.base/java/lang/String.html which returns NOT FOUND (extra "java.base" segment in the middle of the URL path)

[bbatsov]

Hmm, that's pretty weird as we actually have a bunch of unit tests for URLs for different JDK versions - see https://github.com/clojure-emacs/orchard/blob/master/test/orchard/java_test.clj#L199

[jeffvalk]

Regarding the original issue: Is there anything at play that would affect classloaders?

The JDK sources are dynamically loaded by orchard.java; if something causes src.zip to be loaded by a classloader that is too low in the hierarchy, its contents won't be visible on the classpath when orchard.java.parser looks for a particular class' source file. (This is only a potential issue on JDK9+; prior to that, classloaders at the top of the hierarchy were de facto dynamic.)

[jumarko]

@bbatsov those tests look correct but I think the problem is in the info/javadoc-info function which is called on the result and that adds the extra "java.base" segment to the url path in the resolve-javadoc-function.

More specifically, when I tested it with "java.base/java/util/Random.html#nextLong()" it went to the path of dereferencing the javadoc/*remote-javadocs* which for *core-java-api* returns and JDK 11 returns this url: "https://docs.oracle.com/en/java/javase/11/docs/api/java.base/" - notice that "java.base" prefix is already there:

orchard.info> (javadoc-info "java.base/java/util/Random.html#nextLong()")
;;=>
{:javadoc
"https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java.base/java/util/Random.html#nextLong()"}

[jumarko]

@jeffvalk
I'm not sure I can answer your question.
But perhaps it's more related to #2686 ?

I've updated the description to state two things (cider-javadoc not working for JDK 11 and cider-doc not working for classes like java.lang.Module).
I'd say let's ignore my issues with cider-doc and core java.lang classes (at least until I can figure out what exactly is causing the issues or come up with a solid reproducer).

[jeffvalk]

notice that "java.base" prefix is already there

That appears to be true, and hence broken. clojure.java.javadoc/*remote-javadocs* returns wrong URLs for any JDK class not in the java.base module. This includes a lot of common classes (e.g. java.sql.*, java.util.logging.*, etc).

If we want correct URLs, it seems we shouldn't rely on what clojure.java.javadoc currently supplies.

[bbatsov]

Yeah, I think we should just replicate this in orchard. I think this will be pretty simple. Might also be a good idea to open an upstream issue report in Clojure.

[jumarko]

Asked for clarification of the upstream lib behavior here: https://ask.clojure.org/index.php/8422/clojure-javadoc-javadoc-fails-javadoc-classes-outside-module

[dpsutton]

clojure-emacs/orchard#84

fixes this. I've also got a jira ticket to add a doc url for java 13. Can add a backport for this while we wait if desired.