representing hierarchical relationship

Can you suggest me "How can I represent the  hierarchical relationship through  java class?"
you are welcomed to suggest other techniques.

For  instance,   User specifies  that
           

           "Room" belongs-to "Floor" and  "Floor" belongs-to "Center"

 I want to represent this relationship as Java class, and  later want to retrieve this relationship.

-Pankesh 
representing hierarchical relationship
===


Can you suggest me "How can I represent the  hierarchical relationship through  java class?"
you are welcomed to suggest other techniques.

For  instance,   User specifies  that
           

           "Room" belongs-to "Floor" and  "Floor" belongs-to "Center"

 I want to represent this relationship as Java class, and  later want to retrieve this relationship.

-Pankesh 