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How do I track what java is actually looking for as it traverses CLASSPATH?

How is the java utility that begins the process of launching a class told to "spill its guts" on what it's doing as it tries to load classes?
In particular, what file paths is it TRYING to access, only to perhaps discover whatever it's looking for is not there, at least as it interprets the specification given? There was a way to get that information, but I can't find it now.
Note that this is Java version "1.8.0_333" on Windows 10.
I've tried every flag known to me, via the -h and -X flags, and I strongly suspect what I'm looking for is (was) an X flag that's been removed, just as the -X help output warns. And so, there must be an OS way to figure this out, I sure hope!
You might ask why? Whatever for? What are you trying to do? Well, that's the bulk of this question's text. To wit:
As one of the very early users of Java (I started with 1.1) way back in the '90s, I had an issue moving an application suite I'd written for my company on Linux to MS Windows and I got it working by using Cygwin. Along the way, this same sort of issue came up and I quite vividly recall having found a mechanism for getting the Java launcher to articulate just what file specifications - paths - it was actually using in searching for the appropriate class. And through using this, I found that the CLASSPATH was being specified incorrectly, and with some experimentation, I got it working reliably. Now I need to do that again!
This flag I'd used was immensely helpful in figuring out just what the file specification format CLASSPATH needed to be (we're not talking semicolons here) this combination of OS, Java, and Cygwin. After some hours of what I hope was reasonable hunting, I'm wondering if this capability has been removed at some point? Either that or "I'm looking for the wrong thing." Heck, since the source is available (I think!), maybe some brave soul has hacked the java utility to do such a thing?
It may help to understand that for this application I wrote for my company, it was a major goal to have the source work pretty much the same on all Windows and Linux / Unix systems (and at the time, macOS), and just use a configuration file to tell the code what's different. And that wasn't easy to figure out, but with this flag, it wasn't that hard, either.
But, unfortunately, I haven't needed this knowledge since I figured it all out all those years ago, and apparently, this little kernel of knowledge is very hard to find today. Or, it's no longer pertinent to the modern version(s).
I don't think this has anything much to do with the actual problem, but it may help in people's thinking if they understood the scenario: The current situation is that I have a fully functional installation of this software on Windows 7 to use as a comparison for how to configure things on Windows 10 (and hopefully younger). The Windows 7 is running a pretty modern Cygwin installation and very nearly the most modern Java - just a sub-version away from the new installation from last week on a Windows 10 box. (Everything's bright and shiny new on the new box.)
The required format for CLASSPATH on the nearly identical but fully functional Windows 7 system is:
CLASSPATH="C:/opt/OurInstallationDir/lib"
And that's it.
This value is picked up in several places as the code later needs to launch Java itself to do some unusual things. However, the java command that gets it all going is launched from a C program - not that that matters for this problem - but the C program (compiled under Cygwin, but perfectly runnable from any Windows environment) helps ensure that the Java environment is secured (policy file contents and so forth) before getting into Java, else it refuses. And this program on Windows 11 launches Java just fine, it's just giving it a CLASSPATH that isn't useful, apparently, even though the files are there where they should be, etc.
Configuring things as before just doesn't work, even from the command line. No version of specifying CLASSPATH seems to work if it's more than a dot; the only thing that works, is being in the /lib directory when starting and using "-cp ." ... But that's just not going to fly for so many reasons! To be a little more clear, I've tried reversing the slashes, using /cygdrive/c/, and whatever else I could think of. But, at least we know that if you're in the directory and use -cp, it will find and launch the program. So, there's nothing wrong with the Java, just pointing the java utility at it.
Again: How is the java utility that begins the process of launching a class told to "spill its guts" on what it's doing as it's trying to load classes?

You use this construct on the JVM:
java -XX:+TraceClassPaths -cp "C:\opt\SomeDirectory\lib" myClass
I was able to get confirmation of what Java was using, not only for my CLASSPATH, but "internally" by using the above.
The fact that it echoed back both what I was doing and what it was doing somehow gave me the insight to check everything about it. Java itself doesn't work (at all) if it's installed in a location that it thinks has a link in it, and it's own fetches go right back to the system disk specification.
From that I found that Java on Windows won't take a CLASSPATH that has a link in it!
Simply ensuring that the whole tree was specified "from the top" of the drive it's on works. If it's not, it won't.
It's now working happily using the syntax noted above.
This is quite different from every other application I've seen on Windows. But, well, it's Java!
This really came from a pointer from Mark Rotteveel who commented above about this article: How to track when class is loaded and destroyed in jvm? And therein I learned how to get the list of all the options the presently in-use JVM supports. All Java developers should be aware of this in my opinion, so thanks to Mark for that.

Does class.forName("com.mysql.jdbc.Driver") working on current versions of Netbeans?

I have been following several tutorials on YT on how to connect NetBeans with XAMPP and it seems like all the posted videos are older versions of NetBeans.
Whenever I use the Class.forName("com.mysql.jdbc.Driver"); on my command line it shows up with an error of "Class.forName()" should not load JDBC 4.0+ drivers unlike theirs which shows no errors.
Is there an alternative for this command on the current version of NetBeans?
And I can't seem to connect my NetBeans on XAMPP no matter what methods I follow from the internet.

Class.forName to load the driver hasn't been neccessary for 15 years. Whatever book or tutorial got you there, you might want to consider tossing it in the trash and finding something a little bit more up to date.
However, you've made another mistake: You've misjudged what you're looking at. The message "Class.forName()" should not load JDBC 4.0+ drivers is not an error. It is sonarcube warning. (sonarcube is a linting tool: It finds aspects of your code that are definitely or likely bugged or otherwise almost universally derided as bad style and tells you about it).
You should not ignore these warnings - they are pointing at places in your code that are either broken, or will likely break in the future, or are likely to lead to problems (that's what 'bad code style' is: Code that is hard to maintain or otherwise likely to cause unneccessary hardship in the near future).
The fix is trivial. Just ditch the line. Whenever you open a connection, the JDBC system will automatically just figure it out, as long as the driver is on the classpath. You don't have to 'load it' like this.

Connection Reset using Java's FileUtils or BufferedInputStream

we are having problems downloading a file from a remote server. We have a very high chance of getting a connection reset exception, although the same code works fine with other files we download from different servers.
We already tried using BufferedInputStream, but had the same problem there. That's why we switched to FileUtils copyURLToFile() method in hope that this will be a bit more robust. But that didn't improve the problem.
It seems like browsers don't have a problem downloading the file (at least it worked every time we tried), we just have the problem in Java (or Lucee using Java to be precise). Lucee's (and Railo's before that) built in functions had the same problem, that's why we started using Java in the first place. So far with no success.
Are there any ways to make this download more robust?
We also have little to no influence on the server that hosts the file, so ideally we should fix the problem on our side.
Thanks a lot!

How to simulate File::Stat.ino in jruby or java?

I am currently trying to have Logstash work on Solaris with the File Input method. But I am encountering some bugs (see LOGSTASH-665). After digging a lot, it appears that native support for File.stat on my system (SunOS 5.10, JDK 1.6.0_21, 32 bit) is totally deficient, so I am looking for a way to properly handle it.
Specifically I want to access the inode information. Based on the metadata I can gather about the file (like its path and whatever is available on solaris), I want to calculate a number which is unique for that file, and which changes when the file is replaced by another file which has the same name. At first I thought about simply using a hash of the file path and used this function as a replacement, but indeed, when the file is rolled over the number does not change, so I need to also access the ctime information...
..Or make a system call to get the ls -li result to get the real inode number by another way.
Problem is that I never used ruby before, I am more used to java, so I am struggling to find a solution. Every suggestion will be appreciated.

The best solution I know of is to wrap the native call using JNI or JNA.
There do appear to be a couple of projects that have done this, although I haven't used either of them. See this question: Is there a Java library of Unix functions?

Works fine in NetBeans, Have some errors when built

I am in a very very upset situation. My program worked 100% fine when it is in netbeans, but when I build it it has some issues. That is, in my program, there is an one interface and 10 implementation classes. Program calls correct correct implementation class based on how the user save the file (eg: if user save it as game.yellow, it will call "YellowImpl.java", if saved as game.red, then "RedImpl.java" likewise).
But when it is built, it is calling everything fine, instead YellowImpl!! Which means, if the user saves it as game.red, it will call "RedImpl" correctly and same to all other implementations instead YellowImpl. When the user save the file as game.yellow, the program do nothing!!! But this is not happening when it is inside the netbeans! I tried clean and build too, still not good! What is causing this ? Please help!
However, I am unable to provide the code, because it has lot of codings
PS: I am using some libs too

It's difficult to understand exactly what issue you are having with your explaination and no code. However I assume you are having issue with implementation naming conventions.
Perhaps the below link can help.
Java Interfaces/Implementation naming convention

I am agree with #Rhys: it is hard to understand what happens in your application. Just let me give you an advice: do not think (even for 1 second) that there is a bug in java compiler, JVM etc. It is definitely your bug.
How to find it? I suggest you to use remote debugging.
Run your application outside IDE (NetBeans in your case) with enabled remote debugger, connect to it with net beans and debug your application. I believe you will fined the problem within minutes.
How to enable remote debugging? Add the following long string to your java execution command line:
-Xdebug -Xrunjdwp:transport=dt_socket,address=8000,server=y,suspend=n
If something happens in very beginning of your program execution use suspend=y.
Now connect to this application from NetBeans. It is simple, just configure it to port 8000 according to the configuration of your application.
That's it. Good luck.

Thanks a lot for the replies guys. However, I managed to find the issue. That was a simple, capital case!! I have a package called "kolor" and all the implementations are inside that. In my "YelloImpl" class, I have mentioned the package as "Kolor" (Note that "K" is capital). It was fine in netbeans, but outside it wasn't. After clearing this out, everything went fine. Thanks all for the replies again.