2. OO development is iterative
OO development is iterative
OOA/D artifacts feed into implementation
OOA/D artifacts feed into implementation
model in a traceable manner
model in a traceable manner
Some tools generate partial code from UML
Some tools generate partial code from UML
But programming not trivial generation!
But programming not trivial generation!
Programmers make changes as the work
Programmers make changes as the work
out the details
out the details
Therefore, Expect and plan for change and
Therefore, Expect and plan for change and
deviation from design during programming
deviation from design during programming
3. Mapping Designs to Code
Mapping Designs to Code
Write source code for:
Write source code for:
– Class and interface definitions
Class and interface definitions
– Method definitions
Method definitions
Work from OOA/D artifacts
Work from OOA/D artifacts
– Create class definitions for Domain Class
Create class definitions for Domain Class
Diagrams (DCDs)
Diagrams (DCDs)
– Create methods from Interaction diagrams
Create methods from Interaction diagrams
4. From DCD to Java class
From DCD to Java class
public class SalesLineItem
{
private int quantity;
private ProductDescription description;
public SalesLineItem(ProductDescription desc, int qty) { ... }
public Money getSubtotal() { ... }
}
SalesLineItem
quantity : Integer
getSubtotal() : Money
ProductDescription
description : Text
price : Money
itemID : ItemID
...
1
description
Fig. 20.1
Fig. 20.1
5. From Interaction diagram to method
From Interaction diagram to method
Fig. 20.4
Fig. 20.4
2: makeLineItem(desc, qty)
enterItem(id, qty)
1: desc := getProductDescription(id)
:Register :Sale
:Product
Catalog
{
ProductDescription desc = catalog.ProductDescription(id);
currentSale.makeLineItem(desc, qty);
}
6. Collection classes
Collection classes
SalesLineItem
quantity : Integer
getSubtotal()
1..*
Sale
isComplete : Boolean
time : DateTime
becomeComplete()
makeLineItem()
makePayment()
getTtotal()
public class Sale
{
...
private List lineItems = new ArrayList();
}
A collection class is necessary to
maintain attribute visibility to all the
SalesLineItems.
lineItems
Fig. 20.5
Fig. 20.5
What collection class has been added to the design and why?
7. Exception handling
Exception handling
Why is it wise to consider large-scale
Why is it wise to consider large-scale
exception handling strategies during
exception handling strategies during
design modeling?
design modeling?
In UML, exceptions can be inserted as
In UML, exceptions can be inserted as
property strings of messages
property strings of messages
8. Why implement from least-coupled
Why implement from least-coupled
to most-coupled?
to most-coupled?
SalesLineItem
quantity : Integer
getSubtotal()
ProductCatalog
...
getProductDesc(...)
ProductDescription
description : Text
price : Money
itemID : ItemID
...
Store
address : Address
name : Text
addSale(...)
Payment
amount : Money
...
1..*
1..*
Register
...
endSale()
enterItem(...)
makeNewSale()
makePayment(...)
Sale
isComplete : Boolean
time : DateTime
becomeComplete()
makeLineItem(...)
makePayment(...)
getTotal()
...
1
1
1
1
1
1
*
1
2
3
4
5
6
7
Fig. 20.7
Fig. 20.7
