תרשים המחלקות ותרשים העצמים

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Randell Shaw
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1 1 תרשים המחלקות ותרשים העצמים

2 חלק שלישי: ניתוח ועיצוב מערכות מידע באמצעות שימוש ב- UML ומתודולוגיית ה- Process )UP( Unified E1 3 E2 2

3 Outline UML Introduction Class Diagram Class Association Self association Aggregation & Composition Dependency Object Diagram Association Class Diagram: Qualifiers Class Diagram: Association Class Class Diagram: Inheritance (Generalization) 3

4 UML Introdcution - Modeling A model is a simplification of reality. Through modeling we achieve four aims: 1. Models help us to visualize a system as it is or as we want it to be. 2. Models permit us to specify the structure or behavior of a system. 3. Models give us a template that guides us in constructing a system. 4. Models document the decisions we have made. 4

5 UML Introdcution Donald Bell, Staff, IBM. 15 Jun 2003: Way back in the late twentieth century to be exact -- the Object Management Group (OMG) released the Unified Modeling Language (UML). One of the purposes of UML was to provide the development community with a stable and common design language that could be used to develop and build computer applications. UML brought forth a unified standard modeling notation that IT professionals had been wanting for years. Using UML, IT professionals could now read and disseminate system structure and design plans -- just as construction workers have been doing for years with blueprints of buildings. 5

UML Unified Modeling Language Visualizing, specifying, constructing, and documenting objectoriented systems is exactly the purpose of the UML.

6 UML Unified Modeling Language Visualizing, specifying, constructing, and documenting objectoriented systems is exactly the purpose of the UML. Exactly like architects blueprints. The constructing part is debatable. You already know how to speak it (Object-Oriented); here you will learn to read and exercise writing it. 6

7 The Diagrams of UML 2.0 Class diagram (s) Object diagram (s) Sequence diagram (i) State machine (b) Use Case diagram (f) Package diagram (s) These ones we ll see Classification of diagrams: Interaction diagram (i) Communication diagram (i) Timing diagram (i) Activity diagram (f) Component diagram (s) Composite diagram (s) Deployment diagram (s) these ones we won t. (s) structure (b) behavior (f) functional (i) interaction 7

8 Class Diagram Definition: A class diagram is a graphic presentation of the static view that shows a collection of declarative (static) model elements, such as classes, types, and their content, and relationships. 8

9 Class Diagram Basic Elements: Class Class Elements Name Typed Attributes Typed Methods Visual Representation A class is a description of a set of objects that share the same attributes, operations, relationships, and semantics. 9

10 Class Diagram Basic Elements: Association Association Name Roles name Multiplicity a a..b a..* Elements Visual Presentation multiplicity name multiplicity -role -role Association Association - a structural relationship that specifies that objects of one thing (class) are connected to objects of another. Aggregation - an association between two classes or components defined as is part of. Composition - a strong form of aggregation. 10

Recursive data structures, self-reference Examples: Class

11 Class Diagram Basic Elements: Self Association Association can be between a class and itself. Recursive data structures, self-reference Examples: Class Inheritance and Polymorphism, University Courses with Pre- Requisites. How would you model a nodes-and-edges graph? 11

12 Class Diagram Basic Elements: Composition Composition has exactly two rules which differ it from ordinary associations: A constituent part can belong to exactly one assembly. Once a constituent part has been assigned an assembly, it has a coincident lifetime with the assembly. 12

13 Class Diagram Basic Elements: Aggregation Aggregation is a Modeling Placebo does not have any actual semantics. would be treated just like association in code generation, model analysis, etc. 13

14 Class Diagram Basic Elements: Association Aggregation and Composition Wrong! Right! 14

15 Class Diagram Basic Elements: Dependency Dependencies - is a relationship that states that one thing (class) uses the information and services of another thing (class). Underline is the notation for static operation/attributes. Some patterns reduce dependencies usage to a minimum. 15

16 - חברת טיולים דוגמה 1 חברת טיולים מארגנת טיולים מסוגים שונים. לכל טיול יש שם, רשימת ערים לביקור, תאריך יציאה ותאריך חזרה. עיר מוגדר ע"י שם העיר, מדינה, מספר ימי לביקור ופרטיו של המדריך )ת.ז, שם וכתובת (. מדריך יכול להדריך בערים שונים, אך לכל עיר יכול להיות מדריך אחד בלבד. עבור כל טיול מנהלים רשימת מטיילים. מטייל מוגדר ע"י ת.ז, שם, רשימת טלפונים )קוד,מספר( ומחיר לטיול. gm Tour -name -departure -arrival Visua 0..* 1..* gm City -name -country -days Visua 0..* 0..* ad Telephon -code -number Vi 0..* gm 1 -id -name -cost Tourist 1..* 1 Visua gm -id -name Guide -address Visua מה יותר מובן )הסיפור או הדיאגראמה(? 16

17 - קורסים באוניברסיטה דוגמה 2 באוניברסיטה ניתנים קורסים. כל קורס יכול להיות מורכב ממספר סמינרים )אך לא חייב(. לסמינר משובצים סטודנטים. כל סטודנט חייב להשתתף לפחות בסמינר אחד. עוזר ההוראה של הסמינר הוא סטודנט. Pa Pa Pa Student 0..* takes 1..* Seminar section of -student 0..* Course -teaching assistant 1 0..* assists ו- associations roles ברירות המחדל של מאוד חשובים להבנת התרשים והמערכת השתמשו בהם. multiplicity מבלבלות ובעייתיות ציינו במפורש את ה- multiplicity. 17

18 Object Diagram It depicts objects and their relationships at a certain point in time, typically a special case of either a class diagram or a communication diagram [Scott W.Ambler]. It shows instances instead of classes. They are useful for explaining small pieces with complicated relationships, especially recursive relationships. [Randy Miller] It is closely linked to class diagram. Just as an object is an instance of a class, an object diagram could be viewed as an instance of a class diagram. It is used for testing and refining class diagram. 18

19 Object Diagram Basic Elements: Links and Associations Object Name Attributes Links Name Type Elements Association Aggregation Composition Generalizations Dependencies Visual Presentation object name : class -attribute 1 = "value" -attribute 2="value" attribute n="value" -role link :class object name : class name -role Why there is no multiplicity? 19

20 Pa Pa )המשך מדוגמא 2( Pa דוגמה 3 Student 0..* takes 1..* Seminar section of -student 0..* Course -teaching assistant 1 0..* assists a) Right OD b) Wrong OD tali : Student assists takes assists sem1 : Seminar sem2 : Seminar cou1 : Course amir : Student assists sem1 : Seminar amir : Student takes assists sem1 : Seminar ooad : Course ooad : Course 20

21 Pa Pa )המשך( Pa דוגמה 3 Student 0..* takes 1..* Seminar section of -student 0..* Course -teaching assistant 1 0..* assists OD שגוי/תקין?. כמות ה- links לא יכולה לעלות/לגרוע על כמות ה- associations 21

22 Pa Pa Pa דוגמה 4 Student -teaching assistant * takes 1..* Seminar section of -student {NAND} 0..* 0..* Course assists OD שגוי/תקין? tali : Student takes sem1 : Seminar cou1 : Course takes assists sem2 : Seminar amir : Student takes assists sem1 : Seminar ooad : Course 22

23 במדינה יש כמה ערים ולכולם שמות שונים Class Diagram: Qualifiers - מה מהבאים הכי נכון?.a.b.c 23

24 Class Diagram: Association Class An association class is an association whose links have identities. It is possible to define a association class if relationship between classes has additional properties. Association class constraint: A single instance of the association between any 2 instances of the associated class (the regular association constraint). An association class can have attributes. 24

25 Association Class Definitive Example /etc/termcap read John Doe /etc/termcap read-write Mary Brown /usr/does/.login read-write John Doe A rule of thumb Association classes are better for many to many relationships. 25

26 דוגמה 5 עובדים בפרויקט עובדים משובצים לפרויקטים שונים בתפקידים שונים. יש לשמור את תיאור התפקיד ומשכורת של עובד פר פרויקט עליו הוא עובד. a) Class Diagram b) Object Diagram DavidP1:Role -description="manager" -salary="10..." David:Employee p1:project OrenP1:Role -description="tester" -salary="50..." Oren:Employee p2:project OrenP2:Role -description="tester" -salary="50..." The constraint comes from the association semantics. 26

27 What do the diagrams describe? a) b) c) 27

28 Class Diagram: Inheritance (Generalization) Inheritance models is a and is like relationship, enabling you to reuse existing data and code easily. The subclass inherits from super-class: Attribute Operation Relationship Interface 28

29 Class Diagram: Inheritance (Generalization) Some patterns: Create a conceptual subclass of a super-class when: 1. The subclass has additional attributes of interest. 2. The subclass has additional associations of interest. 3. The subclass concept is operated on, handled, reacted to, or manipulated differently than the super-class or other subclasses, in ways that are of interest. 4. The subclass concept represents an animate thing (for example, animal, robot) that behaves differently than the super-class or other subclasses, in ways that are of interest. 29

30 Class Diagram: Inheritance (Generalization) Create a conceptual super-class in a generalization relationship to subclasses when: 1. The potential conceptual subclasses represent variations of a similar concept. 2. The subclasses will conform to the 100% and Is-a rules. 3. All subclasses have the same attribute which can be factored out and expressed in the super-class. 4. All subclasses have the same association which can be factored out and related to the super-class. 30

31 Representing Abstract Concepts and their Concrete Manifestations What is a flight? The plane? The path? Both but in two different contexts? So let s represent it! 31

- מבחן. - 4 עבודות ב- JAVA. הגשה בזוגות דרך ה- System Submission

- מבחן. - 4 עבודות ב- JAVA. הגשה בזוגות דרך ה- System Submission 1 - מבחן. - 4 עבודות ב- JAVA 60% 40% הגשה בזוגות דרך ה- System Submission 2 UML Class Diagrams Packages Class Path JAR Files חלק ראשון: חלק שני: 3 An abstraction of software features A structure that singles