DEV475 Mastering Object-Oriented Analysis and Design with UML ...

DEV475 Mastering Object-Oriented Analysis and Design with UMLWhat Is a Component?What Is a Component?• A non-trivial, nearly independent, andreplaceable part of a system that fulfillsa clear function in the context of a welldefinedarchitecture• A component may be• A source code componentSource FileName• A run time component• An executable componentComponentInterfaceExecutableNameComponentNameOO Principle: EncapsulationMastering Object Oriented Analysis and Design with UMLCopyright © 2003 Rational Software, all rights reserved 34From the UML User’s Guide (Booch, 1999): A component is “a physical andreplaceable part of a system that conforms to and provides the realization of a set ofinterfaces.”Software components include:• Source code components (for example, .h, .cpp files, shell scripts, data files),• Binary code components. Examples include: Java Beans, ActiveX controls, COMobjects (DLL's and OCX's from VB), CORBA objects), and• Executable components (.exe’s).Stereotypes (with alternate icons) may be used to define these specific kinds ofcomponents.Component-based development is the creation and deployment of software-intensivesystems assembled from components. Component software development should notbe confused with object-oriented programming (OOP). OOP is a way to buildobject-based software components. Component-based development (CBD) is atechnology that allows you to combine object-based components. OOP is concernedwith creating objects, CBD is concerned with making objects work together.A component conforms to and provides the physical realization of a set of interfaces.Components are implementation things. They are the physical realization of anabstraction in your design. Interfaces were discussed earlier in this module.2 - 34