VirtualMachine.allClasses() does not return a loaded class when the class is
not initialized. This prevents reloading of the uninitialized class in our
application.

Consider the test case:

public class Main {
 public static void foo(Foo f) {
 }

 public static void main(String[] args) throws ClassNotFoundException {
   //load class, but don't initialize it
   Class.forName("Foo", false, Main.class.getClassLoader());
   //alternative: call Main.class.getMethods();
   new Foo().bar(); // breakpoint here
 }

}

class Foo {
 static {
   System.out.println("Foo initialized");
 }

 void bar() {
   System.out.println("yy");
 }
}

When debugger stops at breakpoint, where Foo is loaded but not initialized,
VirtualMachine.allClasses() does not contain a class Foo as it should,
according to
https://docs.oracle.com/javase/8/docs/jdk/api/jpda/jdi/com/sun/jdi/VirtualMachine.html#allClasses()

jdk1.8.0_131\bin\jdb" Main
Initializing jdb ...
> stop at Main:9
Deferring breakpoint Main:9.
It will be set after the class is loaded.
> run
run Main
Set uncaught java.lang.Throwable
Set deferred uncaught java.lang.Throwable
>
VM Started: Set deferred breakpoint Main:9

Breakpoint hit: "thread=main", Main.main(), line=9 bci=12
9 new Foo().bar(); // breakpoint here

main[1] class Foo
"Foo" is not a valid id or class name.
main[1]

It's not until we initialize Foo that it is then returned by
VirtualMachine.allClasses():

main[1] step
>
Step completed: "thread=main", Foo.<clinit>(), line=16 bci=0
16 System.out.println("Foo initialized");

main[1] class Foo
Class: Foo
extends: java.lang.Object