class Item {

@ManyToMany
   @JoinTable(table = @Table(name = "FUNCTIONITEM_ROLE_LINK"), joinColumns = { @JoinColumn(name = "item_id") }, inverseJoinColumns = { @JoinColumn(name = "role_id") })
   List<Role> roles;



/**
* @param roles
*            The roles to set.
*/
public void setRoles(List<UserRole> roles) {
   this.roles = roles;
}

@Transient
public void addRole(UserRole role) {
   roles.add(role);
}

}

Item newItem = new Item();
newItem.setActionPage("#new");
newItem.setLabel("New");
newItem.addRole(UserDelegate.getRole("user"));