Chapter 10[ 269 ]We then define a factory class for the customer object. The methods that we need to
implement are isLeaf (returns false), newInstance (to create the customer object),
and onNodeCompleted (to save it):
public class CustomerFactory extends AbstractFactory {public boolean isLeaf() {
return false
}public Object newInstance(FactoryBuilderSupport builder,
Object name, Object value, Map attributes
) throws InstantiationException, IllegalAccessException {
Customer customer = null
if (attributes != null)
customer = new Customer(attributes)
else
customer = new Customer()
return customer
}public void onNodeCompleted(FactoryBuilderSupport builder,
Object parent, Object customer) {
customer.save()
}
}The factory for invoices is equally straightforward. The only addition is that we
need to take care of the parent-child relationship between customer and invoice.
We do this by adding a setParent method, which will call addToInvoices on the
customer object if required. We also need to check the value parameter passed to
newInstance to see whether a parent is being set at this point:
public class InvoiceFactory extends AbstractFactory {public boolean isLeaf() {
return false
}public Object newInstance(FactoryBuilderSupport builder,
Object name, Object value, Map attributes
) throws InstantiationException, IllegalAccessException {
Invoice invoice = null
if (attributes != null)
invoice = new Invoice(attributes)