References: Jacquie Barker,Beginning Java Objects; Martin Fowler,UML Distilled, 1/13/ UML

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1 References: Jacquie Barker,Beginning Java Objects; Martin Fowler, Distilled, 1/13/ Programming is like building a house. An architect creates a design, and a builder uses appropriate tools to carry out the design. The builder does not proceed without a blueprint from the architect. Software developers also need a blueprint to create complex systems. The is a toolbox of graphical notations used to produce the blueprint -- a graphical depiction of the software design 1/13/ Many Object technologists were influential contributors to : James Rumbaugh : the Object Modeling Technique (OMT) Grady Booch : the Booch Method (clouds) Sally Schlaer and Stephen Mellor : state diagrams, recursive design approach Rebecca Wirfs-Brock : Responsibility driven design Beck and Cunningham: CRC cards Bertrand Meyer : Eiffel and programming by contract 1/13/

2 Many Object technologists were influential contributors to : Ivar Jacobsen : use cases for formalizing requirements James Martin and James Odell : books on Information Engineering Peter Coad and Edward Yourdon: lightweight, prototype-oriented approach to methods Derek Coleman (HP) : the Fusion method Erich Gamma, Richard Helm, Ralph Johnson, John Vlissides the Gang of Four : Design Patterns 1/13/ Experts in object technology argued for years over notations and process. Software developers could choose from many different methodologies to express their designs; there was no standard means of communication. was the outcome of the methodology wars. 1/13/ Jacobsen, Rumbaugh and Booch - dubbed The Three Amigos - joined their competing modeling languages into one to create a standard notation (i.e. common vocabulary) that developers can use to convey their designs. was adopted as the standard for the OMG (Object Management Group) a consortium that includes over 800 members in /13/

3 is not a method. It does not outline a procedure for designing software; it is a modeling language that captures the design graphically. Most methodologies consist of a modeling language and a process Whatever process you use, you can use to record the results of your analysis and design decisions. Diagrams emerge independent of some process. 1/13/ The main reason to use notation is communication. To discuss design with someone, both need to understand the modeling language, not the process used to come up with the design. Human language is imprecise Code is too detailed 1/13/ Class Diagrams In the analysis & design phases, class diagrams are used to organize the attributes and operations of a class. The simplest class diagram lists only the names of attributes without their types, and lists method names without parameters or types. Simplicity is good name ssn birthdate gpa Student registerforcourse () dropcourse () choosemajor() get and set methods are implied and not shown 1/13/

4 Basic Class Notation A box represents a class Topmost box is the name of the class Middle box lists attributes Bottom box contains operations Graphical notes about your model are depicted in boxes with folded corners Class name <<Class name>> <<Attribute>> <<Operations>> Attributes In an operation is a service Operations that you can request from any object of a class; a method is a specific implementation of the 1/13/2004 operation. 10 Basic Class Notation The characters -, #, and + convey visibility Visibility + public_attr # protected_attr - private_attr + public_opr() # protected_opr() - private_opr() 1/13/ Basic Class Notation Class diagram for the BankAccount class - balance : double BankAccount + depositfunds(amount:double):void + getbalance():double # setbalance():void + withdrawfunds(amount:double):double 1/13/

5 Basic Class Notation Example of a note that conveys meaning Bank + addaccount() + totalholdings() + totalaccounts() + deposit() + balance() The bank holds onto a number of Accounts and provides operations For manipulating those accounts. 1/13/ Class Diagrams Static attributes are underlined totalstudents name ssn birthdate gpa Student registerforcourse () dropcourse () choosemajor() 1/13/ Stereotypes You can make a model more descriptive by using stereotypes. A stereotype is a element that allows you to extend the vocabulary of the language. It consists of a word or phrase enclosed in << >>. A stereotype is placed above or to the side of an existing element. BankAccount <<accessor>> +getbalance() + depositfunds() + withdrawfunds() 1/13/

6 Stereotypes To indicate a class is an abstract class, you either use italic font for the class name or add a constraint. - balance : double + depositfunds(amount:double):void + getbalance():double # setbalance():void BankAccount {abstract} + withdrawfunds(amount:double):double 1/13/