Software Architecture

Transcription

1 Software Architecture Definitions ons.html ANSI/IEEE Std , Recommended Practice for Architectural Description of Software- Intensive Systems Architecture is defined by the recommended practice as the fundamental organization of a system, embodied in its components, their relationships to each other and the environment, and the principles governing its design and evolution.

2 Architecture and Design Software design is often divided into two categories: Software architecture design Top-level design, high-level software structure and organization of components Software detailed design Describing each component sufficiently to allow for its construction

3 Testing V Requirements -> Acceptance Testing Architecture -> System Testing Design -> Integration Testing Construction -> Unit Testing

4 Design Strategies Divide-and-conquer/stepwise refinement Top-down vs. bottom-up Data abstraction and information hiding Use of heuristics Use of patterns and pattern languages Iterative and incremental approach

5 Design Methods Function-Oriented (Structured) Object-Oriented Data-structure-centered Component-based

6 Architectural Styles Sequential Layered/Multitier Client-Server Event-driven Pipe-and-Filter Parallel State-Machine

7 Web Architecture Overview Static html text file containing html tags created manually may include some client-side scripts (e.g. JavaScript) Dynamically generated html html file produced at time of request cgi, php, asp, jsp, Servlets Html with active content html contains a program that runs at the client inside a web browser Java applets, javascript

8 Static HTML web server web browser request URL response HTML.html

9 Dynamically-generated HTML RMI Sockets CORBA EJB application JDBC DBMS web server web browser request URL response HTML.class.jsp.html

10 HTML with Active Content web server web browser.class request URL response HTML.html

11 Dynamically- application generated and Active-content HTML RMI Sockets CORBA EJB JDBC DBMS web server web browser.class request URL response HTML.class.jsp.html

12 Sample Web Architecture with Spring Framework hello.htm web.xml Dispatcher Servlet springapp-servlet.xml ProductManager.java Model Product.java Controller TestProductManager.java SpringappController.java View hello.jsp TestSpringappController.java springapp-servlet.xml build.xml build.properties

13 4+1 Architecture Views from the Unified Process Classes, interfaces, collaborations End-user Functionality Logical View Use cases Use Case View Implementation View Components Programmers Software management Active classes System integrators Performance Scalability Throughput Process View Conceptual Deployment View Physical Nodes System engineering System topology Delivery, installation Communication

14 Modeling CASE Model->code-generation->source code Source code->object code Reverse engineering

15 UML Diagrams Structural Class, Object, Component, Deployment Diagrams Behavioral Use-Case, Activity, Sequence, Communication/Collaboration, Statechart Diagrams

16 Architecturally Significant Classes Organized by Package

17 Architecturally Significant Classes TimeTrackerApplet submitelapsedtime() savelocal() readlocal() 1 1 Timer start() pause() resume() stop() getelapsedtime() <<Servlet>> TMTPageController dopost() doget() <<Servlet>> TimerController dopost() doget() submittimeentry() DBMSInterface submitquery() insert() ReportGenerator generatetaskdurationbyworker() Worker Fullname SSN Address ID Position <<JSP>> ReportResults returnreport() Each report type will correspond to one JSP Most Use Cases will have a corresponding operation here Item Name Description Assignments TimeEntry PerformDate Time W orkorder Task gettaskiterator() : Iterator addtask(t : Task) removetask(t : Task) 1 0..*

18 Class Diagrams Classes, attributes, operations Associations, aggregation, composition Inheritance/generalization

19 Architecturally Significant Interactions : Worker Menu (JSP) 1: Create Report Reports Menu (JSP) TMT Page Controller (Servlet) Report Generator (Servlet) DBMS Interface (JDBC) Report Results (JSP) 2: 3: 4: setworker 5: setproject 6: settask 7: getreport 8: 9: 10: submitquery 11: 12:

20 Communication Diagrams 3: Display Time Sheet( ) 7: Display Time Sheet( ) 1: Get Time Sheet( ) 4: Add Time Entry( ) 8: Submit Time Sheet( ) : Employee : User Interface 2: Get Time Sheet(String) 5: Add Time Entry( ) 9: Submit( ) : Time Sheet Server : Time Sheet 6: create : Time Entry

21 State Diagrams Initial Empty Create Assign Owner and Dates Assigned do/ Add Time Entry do/ Remove Time Entry entry/ Retrieve from DB Submit Submitted Approve Approved Delete Time Sheet Deleted do/ Remove Time Entry [ All Time Entries Removed ] Final Persist / Store in DB

22 Select Wallpaper Activity Diagrams Order Wallpaper Receive Wallpaper [ paneling ] Remove paneling Prepare Walls [ else ] [ old wallpaper ] Remove old wallpaper Patch and Sand Walls Paint Sizing Put Up Wallpaper

23 Logical View Describes an architecturally significant subset of the design model Contains a subset of classes, packages, and use-case realizations Concerns the functionality, behavior, use of frameworks and patterns Uses Class, Interaction, and State Diagrams

24 Process View Describes threads of control and communication between them Concerns the availability, reliability, scalability, performance, synchronization Uses Component, Class, and Collaboration Diagrams TimeTracking Server

25 Implementation View Describes software component organization Concerns team organization and configuration management Uses Component Diagrams TimeTracking Server Database

26 Deployment View Describes physical network configurations Concerns the performance, throughput, fault-tolerance, availability, installation, and maintenance Uses Deployment Diagrams UNIX Server TimeTracking Server Client PC GUI Database