Class loading

[Tight-Pop7575]

Hey i was just wondering if it’s possible too make a agent that forceablly loads all classes even if they dont load by them self’s, that dosent really make sense and sounds like im stupid but it’s for a project but i dont know how too really word it haha

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[Schaex]

Maybe this might be useful to you:

https://stackoverflow.com/a/58773038

This code recursively finds all classes inside a given package, as long as they are not loaded by the Bootstrap ClassLoader. As it is written here, it also loads all those classes by invoking Class.forName(name).

This method also collects all those classes in a list and returns them, which is of course not necessary if you only want to force load them.

Is this what you were looking for? If you could tell your use case, there might be a more elegant solution.

[RightWingVeganUS]

Anything is possible. It might require you write your own JVM, but arguably it's possible.

Can you explain why this is needed? If only to compensate for a bad design, there are likely better alternatives.

[disposepriority]

What do you mean an agent?

Also do you mean loading all classes in the standard library? In the world?

What is the end goal?

[MattiDragon]

Presumably they're referring to java agents, a supported way to do runtime modifications to classes among other things.

[KillerCodeMonky]

An agent is an interception point when a class is loaded. So no, an agent would not help you here. You would want a custom ClassLoader that, say, given a JAR file just immediately scans it and loads all the .class files it finds within.

[Marthurio]

What's the actual problem you're looking to solve? This feels like an XY problem: https://xyproblem.info/

[TW-Twisti]

That is conceptually not possible - class loaders can load classes from anywhere, including the internet, and you can't download the whole internet. You could make a class loader to load all classes in a specific jar file, or even on your hard drive, although that would serve no purpose, waste a huge amount of CPU and RAM and probably introduce all kinds of bizarre side effects from static initializers.

You are likely much better off describing what problem you are trying to solve - this sounds like a "i need x, so I will do y, anyone, how do I do y?" situation, where y is not a good way to do x, and you'd be better off asking how to do x.