Stupid JRE Error

Question

I have a program that compiles succesfully. The name of the .class file that has the Main() routine is Main.class.
I go to run this class from my command prompt and I get the following error:
C:\Program Files\WS_FTP\proj2>java -cp c:\magician\classes Main
Exception in thread "main" java.lang.NoClassDefFoundError: Main
What do you mean it can't find the Main class??!?! It's right there!!!
This is what the directory listing looks like
C:\Program Files\WS_FTP\proj2>dir /w
Volume in drive C has no label
Volume Serial Number is 3910-0625
Directory of C:\Program Files\WS_FTP\proj2
[.] [..] BOOLEA~1.JAV WS_FTP.LOG CYLIND~1.JAV
DOUBLE~1.JAV ELLIPS~1.JAV GLPANE~1.JAV MAIN~1.JAV MAKEFILE
PARAME~1.JAV POLYGO~1.JAV POLYME~1.JAV README SHAPE~1.JAV
TORUS~1.JAV UVSHAP~1.JAV VERTEX~1.JAV WORLDV~1.JAV BOOLEA~1.CLA
PARAME~1.CLA CYLIND~1.CLA UVSHAP~1.CLA SHAPE~1.CLA DOUBLE~1.CLA
VERTEX~1.CLA POLYGO~1.CLA ELLIPS~1.CLA GLPANE~1.CLA MAIN$1~1.CLA
MAIN$2~1.CLA MAIN$3~1.CLA MAIN~1.CLA WORLDV~1.CLA POLYME~1.CLA
TORUS~1.CLA HELLOD~1.JAV
35 file(s) 84,030 bytes
2 dir(s) 4,967.33 MB free
Can anyone help with this?
Thanks!!!

Answer 1

So you told java to run your class using "c:\magician\classes" as the classpath. You say "It's right there!!!" but then go on to demonstrate that in fact it isn't right there, it's somewhere else, in "C:\Program Files\WS_FTP\proj2". That exception (NoClassDefFoundError) means that java can't find the file in your classpath, which is correct since Main.class isn't in "C:\magician\classes".
Try changing your classpath to include the directory where Main.class is located. Simplest way to do that in your case is
C:\Program Files\WS_FTP\proj2>java -cp .;c:\magician\classes Main
(In case you didn't know, "." is a DOS shortcut meaning "the current directory.)