New to Java -- Need to know if something is possible

We have an application in which some complex calculations are being done in MatLab. In order to speed things up, we are converting it to C/C++. But there is also a GUI in the MatLab code. This is all to run on Windows.
We will eventually (2 - 4 months from now, after it has been successfully converted and running) need to also port it to Linux. I am thinking that I would like to write the GUI portion in Java, so that it can be easily transferred from Windows to Linux.
There is also an "embedded" portion running in C/C++. This must remain in C++ in because it is a real-time application where literally each microsecond will matter, Java will be too slow. In addition, some of the calculations will run on a parallel processing board, and the COTS libaries that support running on the card are C/C++ libraries.
So, what I want is, to make a Java GUI that I can move from Windows to Linux, and in this GUI, each of the callbacks will then do nothing but call a C++ routine. I need the C++ routine to run completely independent of the Java Virtual Machine, to preserve the speed of the C++ library.
My questions:
If I write the GUI in Java, and have separate libraries/fucntions in C/C++ that are compiled for both Windows and Linux, can the Java GUI call these, and will they run as fast as they would in a normal C++ app? Or will it be slowed down by the JVM, and run at "interpreter speed"?
How do you call the C++ code from inside a Java interpreter? Do we compile it all in a dll, and the dll is called from Java? Do we make a C++ library, and that can be called from the Java GUI? Or is there something else. This must have been done many times, does anybody have any suggestions or experience to get me going. I think I can glom together a simple Java GUI ( I produced some Java programs several years ago), and I can get the C++ libraries going, it is connecting them that I could use some guidance.
Thanks.
- Martin

georgemc wrote:
DrLaszloJamf wrote:
georgemc wrote:
DrLaszloJamf wrote:
georgemc wrote:
Ignore the myth that Java executes slowly because it's "interpreted". It's notHear, hear. Brian Goetz is a good source of Java myth debunking. Check out his columns:
http://www.ibm.com/developerworks/views/java/libraryview.jsp?search_by=practice:
Indeedie. Here's his article I like to trot out on occasions such as this
http://java.sun.com/developer/technicalArticles/Interviews/goetz_qa.html
I love to point out on some benchmarks, Java can be faster that C. "Faster than C? That's impossible!", people sputter, as if C were a physical constant, like the speed of light -- that's "c", folks!That's borne out of the misconception that any operation in Java is simply translated by the runtime into a similar operation in native code, and, were that the case, they'd probably have a point. It completely ignores runtime optimizationsAnd other things like Java's object allocation/GC being superior to malloc(), ...

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