Component Diagram :
A component diagram provides a physical view of the system. Its purpose is to show the dependencies that the software has on the other software components (e.g., software libraries) in the system. The diagram can be
shown at a very high level, with just the large-grain components, or it can be shown at the component package level.2
Modeling a component diagram is best described through an example. Below Diagram shows four components: Reporting Tool, Billboard Service, Servlet 2.2 API, and JDBC API. The arrowed lines from the Reporting Tool component to the Billboard Service, Servlet 2.2 API, and JDBC API components mean that the Reporting Tool is dependent on those three components.
The deployment diagram shows how a system will be physically deployed in the hardware environment. Its purpose is to show where the different components of the system will physically run and how they will communicate with each other. Since the diagram models the physical runtime, a system’s production staff will make considerable use of this
The notation in a deployment diagram includes the notation elements used in a component diagram, with a couple of additions, including the concept of a node. A node represents either a physical machine or a virtual machine node (e.g., a mainframe node). To model a node, simply draw a three-dimensional cube with the name of the node at the top of the cube. Use the naming convention used in sequence diagrams: [instance name] : [instance type] (e.g., “w3reporting.myco.com : Application Server”).
The deployment diagram above shows that the users access the Reporting Tool by using a browser running on their local machine and connecting via HTTP over their company’s intranet to the Reporting Tool. This tool physically runs on the Application Server named w3reporting.myco.com. The diagram shows the Reporting Tool component
drawn inside of IBM WebSphere, which in turn is drawn inside of the node w3.reporting.myco.com. The Reporting Tool connects to its reporting database using the Java language to IBM DB2’s JDBC interface, which then communicates to the actual DB2 database running on the server named db1.myco.com using native DB2 communication. In addition to talking to the reporting database, the Report Tool component communicates via
SOAP over HTTPS to the Billboard Service.
UML Objects oriented Concepts:
UML can be described as the successor of object oriented analysis and design.
An object contains both data and methods that control the data. The data represents the state of the object. A class describes an object and they also form hierarchy to model real world system. The hierarchy is represented as inheritance and the classes can also be associated in different manners as per the requirement.
The objects are the real world entities that exist around us and the basic concepts like abstraction, encapsulation, inheritance, polymorphism all can be represented using UML.
So UML is powerful enough to represent all the concepts exists in object oriented analysis and design. UML diagrams are representation of object oriented concepts only. So before learning UML, it becomes important to understand OO concepts in details.
Following are some fundamental concepts of object oriented world:
- Objects: Objects represent an entity and the basic building block.
- Class: Class is the blue print of an object.
- Abstraction: Abstraction represents the behavior of an real world entity.
- Encapsulation: Encapsulation is the mechanism of binding the data together and hiding them from outside world.
- Inheritance: Inheritance is the mechanism of making new classes from existing one.
- Polymorphism: It defines the mechanism to exists in different forms.