Dynamic Loading Class in RMI

I create a interface...and implement in SERVER Directory ....
when i RUN client i got Exception CLASS DEF NOT FOUND....

FIRST I START WEB SERVER in (download directory) first window
1) ---> java NanoHTTPD 8080

then i start rmi registry ( second window)(RMIDIR Directory)
2) ---->RMIREGISTRY
then i start Server (Third window) (Server Directory)
3) ---->java -Djava.rmi.server.codebase=http://localhost:8080/ WarehouseServer
then i start client
(Four window) (client Directory)
4) ---->java WarehouseClient
when i run client then i got exception class name not found.....because i use Interface object in client code......

SO HOW DYNAMIC DOWNLOADING CLASS IS DONE???

if I Manually Copy CLASS file IN CLIENT directory then program successfully run.......
PLEASE TELL ME HOW TO do a DYNAMIC DOWNLOADING CLASS.......

You need to KeepItDown

Does the troubleshooting tips here help?