Is the Java classpath final after JVM startup?

Question

I have read a lot about the Java class loading process lately. Often I came across texts that claimed that it is not possible to add classes to the classpath during runtime and

Answer 1

So shouldn't it be possible to add a JAR or *.class file to the classpath after the JVM started ...

You add jars and directories to the classpath, not classes. The classes are in either the directory, or the jar.

And if not, does that mean that the classpath is searched on JVM startup and all fully qualified names of the found classes are cached in an internal "list"?

That could be easily tested: Set the classpath, start your program, move a new class into the CP, call 'Class.forName ("NewClass") from your program. Does it find the new class?