PurchaseOrder (OpenJPA Parent POM 3.0.0 API)

All Implemented Interfaces:

Serializable
```
@Entity
public class PurchaseOrder
extends Object
implements Serializable
```
A persistent entity to demonstrate Master in a Master-Details or Composite pattern for persistent domain model.
The Purchase Order - Line Items relationship typically demonstrates a Master-Details pattern. In JPA 2.0, following new features are added to support this common pattern used in domain modeling, and this example demonstrates them.
Compound, Derived identity: This feature allows the Details type to compose its identity from the the Master's identity.
Orphan Delete or Dependent relation: This feature allows to impose composite relation semantics to normally associative relation semantics implied in Java. Composite relation in persistence terms also translates to deletion of Details record from database when the details lose their relation to master.
Besides the above two key features, this persistent type also shows usage of
Auto-generated identity.
Enum type persistent attribute.
Date type persistent attribute.
One-to-One uni-directional, immutable mapping to Customer.
One-to-Many bi-directional, immutable mapping to LineItem.

Nested Classes
Modifier and Type	Class and Description
`static class`	`PurchaseOrder.Status` Enumerates the status of a Purchase Order.

Constructors
Modifier	Constructor and Description
`protected`	`PurchaseOrder()` A protected constructor satisfies two purposes: i) Status and creation time is set consistently.
	`PurchaseOrder(ShoppingCart cart)` Construct a new order by transferring the content of the given ShoppingCart.

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`Customer`	`getCustomer()` Gets the customer who placed this Purchase Order.
`Date`	`getDeliveredOn()` Gets the time when this order was delivered.
`long`	`getId()` Gets the immutable, auto-generated persistent identity of this Purchase Order.
`List<LineItem>`	`getItems()` Gets the items for this Purchase Order.
`Timestamp`	`getPlacedOn()` Gets the time when this order was placed.
`PurchaseOrder.Status`	`getStatus()` Gets the status of this Purchase Order.
`double`	`getTotal()` Gets the total cost of all the items in this order.
`boolean`	`isDelivered()`
`void`	`setDelivered()` Sets the status of this Purchase Order as delivered.

Class PurchaseOrder