The document discusses various topics related to deriving solutions for web applications, including object-oriented software engineering, modeling, measurement and estimation, design patterns, web applications, XML, software components, web services, and future trends. It covers modeling approaches like UML, metrics for estimation and quality evaluation, design patterns for common problems, standards for XML, components, and web services. It also discusses service-oriented architecture, SOAP, WSDL, UDDI, and packaging of reusable assets.

1. Deriving a solution which satisfies web application requirements

2.  Introduction
 Object Oriented Software Engineering
 Modeling and System Specification
 Software Measurement and Estimation
 Design with Patterns
 Web Application
 XML
 Software Components
 Web Services
 FutureTrends
 Conclusion
 Questions

3.  Simple modeling is essential.
 UML is used for software design.
 ObjectOrientedAnalysis is intuitive approach
of Domain Analysis
 Object Model is used in OOA

5.  Modeling is based on abstraction of world
phenomena
 System specification notations:
 UML State Machine Diagrams
 UML Object Constraint Language (OCL)
 TLA+ Notation
 Problem Frames are used for specifying
problems
 Goal-oriented requirements engineering

6.  Two types of measurement:
1. Done before development to estimate the product duration
2. Done after development to evaluate the product quality
 Use case points (UCP) method is used for effort
estimation
 Cyclomatic Complexity is used to measure the
complexity of program’s conditional logic
 Class cohesion can use Interface-based or Code-based
metrics
 Coupling metrics could be high or low
 Psychological Complexity could be measured by
Algorithmic Information Content (AIC) and Logical
Depth

7.  Convenient solutions for software design
problems
 Must be need-driven
 In Broker method, a client object invokes
methods of a remote server object
 Publisher-subscriber design pattern is used to
implement indirect communication
 Other patterns include Command, Decorator,
State and Proxy patterns.
 Concurrent Programming helps in easier
programming of reactive applications
 Security with obscurity

8.  Unlike traditional software, theWeb serves as
both development & user platform
 A Web application is a system that utilizes
W3C standards & technologies to deliver
Web-specific resources to clients.

10.  Product
 Usage
 Development
 Evolution

11.  eXtensible Markup Language
 Markups: Element, Entity reference, Comments,
Processing instructions, Marked sections,
Document type declarations
 XML Schema provides the vocabulary to state
the rules of document production.
 XPointer supports internal addressing.
 XLink allows us to create and describe links
between resources.
 XSL can translate XML documents that comply
with two different XML schemas.

12.  Components are reusable pieces of software.
 Component communicates with the rest of the
world only via its ports using events.
 Two major component architectures are:
 JavaBeans from Sun
 ActiveX controls from Microsoft .
 Computational reflection is a technique that
allows a system to maintain information about
itself (meta-information) and use this
information to change its behaviour (adapt).
 Object serialization is used to extract the object
state.

14.  Simple Object Access
Protocol
 XML based
 Encoding format for
inter-application
communication
 Document style and
RPC style
communication
 Runs on HTTP etc.
<Header>
header blocks
</Header>
body blocks
attachment blocks

15.  Service description can be
partitioned into parts
which describe :
 individualWeb services
 relationships between sets of
Web services
 WSDL (Web Service
Definition Language)
describes individual web
services
 WSDL Document can be
used to generate stub and
skeleton proxies which
interact with SOAP based
middleware

16.  Discovery agency level connection is a
publish/find mechanism
 Could be used at build-time or runtime
 Universal Description, Discovery, and Integration
is an implementation of discovery agency
 UDDI registry offers common repository for:
 service providers to publish service information
 service requestors inquire to find service information
 UDDI defines structure, publish/inquire API for
registry

17.  Apache eXtensible Interaction System
 Web Service development toolkit
 SOAP engine
 Framework for constructing SOAP servers,
clients, gateways, etc.
 It contains:
 server that plugs into servlet engines
 Java2WSDL
 WSDL2Java

18.  An OMG (Object Management Group) standard
 Used to package digital artifacts
 Guideline and recommendation of reusable
software assets:
 structure
 content
 description
 To increase reusability of software assets
 Encourage consistent and standard packaging

19.  Aspect Oriented Programming
 OMG MDA
 Autonomic Computing
 Software-as-a-Service (SaaS)
 End User Software Development
 The Business of Software

20.  XML is used for data representation onWeb
 Reusable software components are beneficial
 Service OrientedArchitecture involves client,
server and discovery agency
 SOAP is XML based protocol for inter-
application object communication
 WSDL is used forWeb service description
 UDDI implements discovery agency
 ApacheAxis is aWeb Service development
toolkit
 Reusable Asset Specification is an OMG standard
for packaging digital artifacts