The problem

I want to run java code from the command line, and I don’t understand why I manage to do that from within the folder holding the code, but not from another folder. I am on Windows and am using Cygwin.

Example 1: What works

The folder /usr/local/lib/mytoolfolder/ contains two folders with java code:

• mytool/(containing the class I want to run)
• utils/ (containing dependencies)

If I do

$ cd /usr/local/lib/mytoolfolder/
$ java -cp ".;utils/bin;utils/lib/*;mytool/bin;mytool/lib/*" mytool.MyTool

… the class MyTool is called without any problems, and I get the expected output.

Example 2: What does not work

If I cd to a random other folder on my computer and try to call MyTool again, now including the full paths in the class path, like so:

$ java -cp "/usr/local/lib/mytoolfolder/.;/usr/local/lib/mytoolfolder/utils/bin;/usr/local/lib/mytoolfolder/utils/lib/*;/usr/local/lib/mytoolfolder/mytool/bin;/usr/local/lib/mytoolfolder/mytool/lib/*" mytool.MyTool

… I get this ClassNotFoundException:

Error: Could not find or load main class mytool.MyTool
Caused by: java.lang.ClassNotFoundException: mytool.MyTool

What I have tried

I have checked that the classpaths are correct and I have checked permissions.

Question

I understand that this error means that java can’t find the class (obviously). I assume that this is because there is something wrong with the classpath (as Example 1 rules out that there is something wrong with the code itself).

I don’t understand WHAT is wrong with the classpath, or with this approach. Where is the flaw in my logic? And how can I make it work?

Additional tips to debug this further are also appreciated.