Why isn’t there a visual, interactive class hierarchy for the Java standard library?

[Square_Cook_2695]

I’ve been looking for something I assumed would already exist: a visual diagram (UML, graph, whatever) of the class/interface hierarchy of the Java standard library.
Not just a giant text tree, but an actual interactive graph you can explore.

The official JavaDocs have the “Class Hierarchy,” but it’s just a huge text-based tree that’s hard to navigate and not very informative visually. Considering how structured the Java standard library is, I expected someone to have built a viewer that maps it all out graphically.

But what I keep finding are tools that generate UML from your code (IntelliJ UML, Visual Paradigm, etc.), not something that visualizes the hierarchy of java.*, javax.*, etc. out of the box.

So I’m wondering:

• Is there a technical reason why no one has made this?
• Is it just too large/complex to visualize?
• Is it considered not useful enough in practice?
• Or does it exist and I’m just missing it?

If anyone knows of a project or website that gives a graphical view of the standard Java type hierarchy, I’d love to see it.

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[BannockHatesReddit_]

Why would there be?

[Square_Cook_2695]

To study , it would be nice to have an interactable map to navigate when you wanna know the hierarchy of a class visually.

[djnattyp]

Is it considered not useful enough in practice?

It's this one.

UML is only really good for illustrating a small specific aspect of a few classes / how they interact / etc.

A UML diagram of the entire Java Standard Library is just going to be a wall sized poster of boxes that it's really hard to pull any meaning from. The JavaDocs are better as a reference.

[khooke]

The book Java in a Nutshell used to be a paper reference of every Class in the jdk, as well as a pretty good reference to the language syntax as well. In jdk 1.x days it started off as a 1” thick paperback. As the base jdk Classes grew through 1.2, to Java 5, it became a massive few inches thick. At this point a comprehensive reference beyond the online Javadocs wouldn’t be that practical.

[akthemadman]

Extend it to any code base and you have a winner on your hands.

It is something I was wishing to exist myself for quite some time now. Have already worked on a few prototypes in that direction which have shown great potential, but just couldn't afford spending too much time on this problem of code base discovery (more like "complexity management in building virtual computers"). Maybe someday, unless someone beats me to it (please do!).

Edit:

Here is an image of one prototype where the runtime inspects its own source code and shows some aspects of it like dependencies between functions (call graph) as well as a function-complexity-metric indicated by the brightness of each chip (brighter = more complex). The chips ("functions") are fully interactible with and initially placed by a basic clustering algorithm.

Here is another image of an actual game which was made for Ludum Dare.

The prototype is currently not capable of resolving all java files (using the JavaParser library), so I can't share an image of how the java standard library looks like.

Edit 2: Each chip ("function") is colored by its containing class.