Java Development Tools

Ok so i was being helped by someone on here and it was very helpful, so another problem maybe someone can answer. In jdeveloper my code will run, everything is correct. I looked at the output path of where it stores the class file and went there and got the class file and from a command prompt i tried "java class file name and thought it would run it. it gave me errors however in jdeveloper it runs no problem.

I was talking with someone that stated it wont run without jdeveloper because jdev does some work in the background, the work is that it knows what package it is coming from or what not.

so my question is what additional information would i need to input when simply running java class file name that jdeveloper includes in the back ground or should i simply copy the code from the .java file and compile it from my command prompt hence making a new class file construted through command prompt?