I knew hibernate can lazy a collection. But most time I found so many class have association(not one-to-many). If I load one instance, it perhaps load A,B,C,D,E and so on. Sometime I need all class (A-E) for business but sometime I only need A,B. That means at this time I don't care infomation about C, D, E though it has association between A, B, C, D, E.
Can hibernate lazy init C, D, E in when the association is many-to-one, one-to-one?

Read the documentation, chapter "performance".