Trying To Make A Spigot Plugin, Struggling With First Part

So i learned that the first part to make a spigot plugin is get buildtools.jar, which I did. But now, Im trying to build it in command prompt (I use windows) and it won't work. Im doing this:

Code:

java -jar BuildTools.jar

And here is the error message I get:
Unable to access jarfile BuildTools.jar



So, what am I doing wrong?
Just as a side note, yes, I did put the directory in before typing that in.

 

If your java path isn't set right, that won't work

 

SPIGOT
You know what that's another word for?
Heheh

 

A faucet thingy