Hi,
ECC doesnot have java part (portal). YOu need to install a standalone portal system (EP) and then configure it accordingly to connect with backend systems (ECC, BI, etc.).
For this you need to configure SSO connection between EP and backend systems..
Creating System objects, respective iViews and so on.... please read below blog for more info..
How to Connect to SAP R3 System through Enterprise Portal 7.0 Using an iView. - Portal - SCN Wiki
Regards,
Prithviraj.