Hi,
this is my first post in this forum..I am developing a web app that has an Invoice,CartItem,Customer classes..I need to identify the kind of mapping I need to create.

A user creates cartitems and adds them to ShoppingCart .
An Invoice has a Customer and a Set of CartItem objects.I believe cartitem is not dependent upon the invoice's lifetime.So, when an invoice is deleted,the cartitems should not be deleted.

I tried to create the Invoice.hbm.xml and used <set> to associate cartItems to Invoice and decided to not to mention cascade option so that deletion of Invoice does not affect cartitems.

I would like some advice/opinion regarding this..Is this the right way of mapping the associations?
I have copied relevant portions of the code below..Please tell me if this is the correct way.

thanks,
mark

Invoice.java
==========
public class Invoice {
private Customer customer;
private Set<CartItem> cartItems;
private Date invoiceDate;
private int invoiceNumber;
private boolean isProcessed;
public Invoice() {
super();
isProcessed = false;
cartItems = new HashSet<CartItem>();
}
...
}
CartItem.java
========
public class CartItem {
private Product product;
private int quantity;
...
}

Invoice.hbm.xml
==========
...
<class name="Invoice" table="INVOICE">
<id name="invoice_id" column="INVOICE_ID" type="long">
<generator class="native"/>
</id>
<property name="invoiceDate" type="date" column="INVOICE_DATE" />
<property name="invoiceNumber" type="int" column="INVOICE_NUMBER" unique="true"/>
<property name="isProcessed" type="boolean" column="IS_PROCESSED" />

<many-to-one name="customer" class="Customer" column="CUSTOMER_ID" lazy="false" />

<!--when an invoice is deleted the cart items should not be deleted -->
<set name="cartItems" table="CARTITEM" lazy="false" >
<key column="INVOICE_ID" />
<one-to-many class="CartItem" />
</set>
</class>
...