Scribd
Upload
108 views8 pages

Package Diagrams: Massimo Felici Room 1402, JCMB, KB 0131 650 5899 Mfelici@inf - Ed.ac - Uk

Package design needs to balance diverse needs Easier to build and test Better tracking and property transparency Working at a stable overview without the noise of low-level details Less conflict between distributed teams Easy refactoring and extension Vulnerable to changes (in other packages) 2004-2006 SEOC - Lecture Note 08 4 Importing and Accessing Packages Creates relationships between classes of the same name merge is a directed relationship

Uploaded by

api-26462544
Copyright
© Attribution Non-Commercial (BY-NC)
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
108 views8 pages

Package Diagrams: Massimo Felici Room 1402, JCMB, KB 0131 650 5899 Mfelici@inf - Ed.ac - Uk

Package design needs to balance diverse needs Easier to build and test Better tracking and property transparency Working at a stable overview without the noise of low-level details Less conflict between distributed teams Easy refactoring and extension Vulnerable to changes (in other packages) 2004-2006 SEOC - Lecture Note 08 4 Importing and Accessing Packages Creates relationships between classes of the same name merge is a directed relationship

Uploaded by

api-26462544
Copyright
© Attribution Non-Commercial (BY-NC)
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
You are on page 1/ 8

Package Diagrams

Massimo Felici
Room 1402, JCMB, KB
0131 650 5899
mfelici@inf.ed.ac.uk
Rationale
ƒ Provide a way to group ƒ Package design needs to
related UML elements balance diverse needs
and to scope their • Easier to build and test
names • Better tracking and
property transparency
ƒ Provide a way to • Working at a stable
visualize dependencies overview without the
between parts of your noise of low-level details
system • Less conflict between
• Vulnerable to changes (in distributed teams
other packages) • Easy refactoring and
ƒ Provide support for extension
analysis
ƒ Determine compilation
order

© 2004-2006 SEOC - Lecture Note 08 2


Representation of Packages
ƒ Packages contain different
elements (packages too)
ƒ A UML package establishes a
namespace
• To specify the context of a
UML, you provide the fully-
scoped name
• packageName::className
• In Java, a fully-scoped name
corresponds to specify the
Java package
ƒ It is possible to specify
visibility for owned and
imported elements
• public or private
• No elements – no
assumptions about the
package’s content

© 2004-2006 SEOC - Lecture Note 08 3


Element Visibility
ƒ Elements with public visibility are accessible
outside the package
ƒ Elements with private visibility are available
only to other elements inside the package
ƒ In Java, public and private visibilities
correspond to a class being public or private
to a Java package
ƒ If the public keyword is absent, then the
class is private to the package

© 2004-2006 SEOC - Lecture Note 08 4


Importing and Accessing Packages
ƒ <<import>>: Elements
of imported packages Target Packages
are available without
qualification in the
importing package
• public visibility
• private visibility
• Import specific elements,
rather than the whole
package
ƒ <<access>>:Accessing
packages whereas gives
private visibility to the
imported elements

© 2004-2006 SEOC - Lecture Note 08 5


Merging Packages
ƒ Creates relationships between classes of the same
name
ƒ Merge is a directed relationship
ƒ Rationale: the evolution from UML 1.x to UML 2.0 -
extending a base concept of elements without
renaming
ƒ Some Rules for package merge
• Private members are not merged
• Merging classes are generalized to corresponding merged
ones
• Maintain package scope for reference to classes
• Classes outside the intersection of packages are unchanged
• Subpackages are added, if they don’t exist
• Merge extends to subpachages with the same names
• Merge acquires imported elements

© 2004-2006 SEOC - Lecture Note 08 6


Package Dependencies
ƒ Structuring a Project with
Packages
ƒ Packages group UML
elements and organize a
logical system during design
and implementation
ƒ Manage Dependencies
• Directed dependency graphs
• Avoid cyclical package
dependencies
• Organize and allocate
project work to different
teams - Different groups
can work on different
packages without
destabilizing each other

© 2004-2006 SEOC - Lecture Note 08 7


Use Case Packages
ƒ Using packages to
organize use cases
ƒ Organize the functional
behavior of a system
ƒ Highlight which actors
interact with which
portions of the system

© 2004-2006 SEOC - Lecture Note 08 8

You might also like