1 / 19

Chapter 25 - 28

Chapter 25 - 28. Object-Oriented Practices. Agenda. Object-Oriented Concepts Terminology Object-Oriented Modeling Tips Object-Oriented Data Models and DBMSs OODBMS Manifesto Object Management Architecture Common Object Request Broker Architecture. Object-Oriented Concepts.

olathe
Download Presentation

Chapter 25 - 28

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 25 - 28 Object-Oriented Practices

  2. Agenda • Object-Oriented Concepts • Terminology • Object-Oriented Modeling Tips • Object-Oriented Data Models and DBMSs • OODBMS Manifesto • Object Management Architecture • Common Object Request Broker Architecture

  3. Object-Oriented Concepts • Abstraction – encapsulation and information hiding • Identifying the essential aspects of an entity (Object) • Abstract Data Type (ADT): interface part (operation) implementation part (data structure) • Encapsulation • An object has data structure and operations • Information hiding • Internal details • Data independence

  4. Terminology • Object Identity • Classes • Operations, methods & messages • Inheritance • Polymorphism

  5. Object Identity (OID) • System generated • Unique to that object • Invariant • Independent of the values of its attributes • Invisible to the user • Advantages: • Fast, efficient, independent of content, not changeable by user

  6. Class • Definition • Group of objects with similar properties (attributes), common behavior (methods), similar relationship to other objects, and common semantics. • Diagram • Box: class name, attributes, operations (methods) • Superclasses & subclasses • Generalization & specialization

  7. Inheritance • Definition • A subclass inherits the attributes, operations, and association of its superclasses • Types • Single inheritance: one superclass • Multiple inheritance: two or more superclasses • Repeated inheritance: common superclass • Selective inheritance: limited number of properties from the superclass

  8. Operations Methods & Messages • Operations • Function or procedure may be applied to or by objects in a class • Methods • The implementation of an operation for a class • Messages • Communication between objects to execution of a method

  9. Link & Association - 1 • Link • A physical or conceptual connection between objects • Link attribute describes property of an association • Association • A description of a group of links with common structure and common semantics • Has a name (roles for problem description) • A link is an instance of an association

  10. Link & Association - 2 • Qualified association • The objects in a many role are partially or fully disambiguated by an attribute called the qualifier • A small box on the end of the association line near the source class • Multiplicity • The number of instances of one class that may relate to a single instance of an associated class • one, many, zero or one

  11. Polymorphism • Overloading • The name of a method to be reused within a class definition or across class definitions • Overriding • The name of property to be redefined in a subclass • Dynamic binding • Runtime determination of object and method

  12. Object Modeling Tips • Scope • Simplicity • Layout of diagram • Name (descriptive, crisp, and unambiguous) • Association (foreign keys) • Multiplicity • Qualifiers • Review

  13. Object-oriented DBMSs • Object-oriented data model (OODM) • A logical data model of objects supported in object-oriented programming • Object-oriented database (OODB) • A persistent and sharable collection of objects defined by an OODM • Object-oriented DBMS (OODBMS) • The manager of an OODB

  14. OODBMS Manifesto - 1 • Support complex objects • Support object identity • Support encapsulation • Support types or classes • Support inheritance between types or classes • Support dynamic binding

  15. OODBMS Manifesto - 2 • Completed computational DML • Extensible data types • Data persistence • Support very large databases • Support concurrent users • Backup & recovery • Support simple way of querying data

  16. Object Management Architecture (OMA) • Object Model (OM) • A design-portable abstract model for communicating with OMG (Object Management Group)-compliant object-oriented systems • Object Request Broker (ORB) • Handles distribution of messages between application objects (software bus) • Object Services (concurrency control, security, persistence etc.) • Common Facilities (printing, e-mail etc.) • Common Object Request Broker Architecture (CORBA) • Enable client-server interaction with a specific implementation of ORB

  17. Points To Remember • Object-Oriented Concepts • Terminology • Object-Oriented Modeling Tips • Object-Oriented Data Models and DBMSs • OODBMS Manifesto • Object Management Architecture • Common Object Request Broker Architecture

  18. Assignments • Review chapters 5-6, 11-18, 25-27 • Read chapters 19 and 20 • Exam 3 • Date: • Project • Due date: • Place:

  19. End of MIS150 • Exam date: 12/9/03 • Study! Study! Study! • Have a happy and safe holiday!!

More Related