adding biz logic to java beans? (memory)

[Joshua]

hi all.
i am new to java (was dotnet developer)
i am designing a bit complex system based on MVC pattern.
what i am wondering is, what's gonna happen if i implement complex
business logic into java beans, which is for only jsp pages?

i've already finished the first design phase.
my java bean classes contain another java bean classes as their
property. could this design yield some memory problem when deployed?
should java beans contain only primitive types?

help poor java beginner...-_-