Download Lecture 02 Object Oriented Programming

Lecture 16
Other Issues in Java
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Outline
• Case study
– Financial institution
• Java Wallet
• Rapid Development
• RMI
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Java and Business Perspective
• Competitive forces in financial institution to
adopt new technology
– Increasing high fixed cost
– Generating high-margin revenues and
lowering costs of providing services
•
•
•
•
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The need for improved technology
The availability of standard payment protocols
The system reliability for 24 X 7 operations
The flexibility of the platform to absorb new
capabilities
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Evolution of Technology
• Banks were among the earliest pioneers
to apply computing technology to their
business
1966
Back office
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1976
Teller
Desk top
1986
ATMs
1996
Off-site
interface
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Technology Needs of the Financial Service
• Major issues
– Open systems
• More than 200 different proprietary systems are inefficient
• IT professionals want open standards and protocols
– Hardware platform
• Use the same hardware in a variety of client locations
• Run applications in various systems
• Provide all the advantages of a rapid application
development
• Allow reuse of the same code based in variety of different
applications along with object-oriented technology
• Allows to take advantage of the platform independence
provided by Internet technologies
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Technology Needs of the Financial Service
• Movement toward electronic payment
mechanism
– Paper based: $.60/transaction to process
– Electronic based: $.02/transaction to process
• Data warehousing
– Huge transactional databases contain
information about customer purchasing habits
• Valuable what services to provide
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Limitations Implementing New
Technologies
•
•
•
•
•
Security
Protection of private data
Authentication
Reliability
Flexibility
– Financial institution doesn’t know what
applications are going to win
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Java Solutions: Java Commerce
• Java commerce provides a complete
infrastructure for Internet-based electronic
commerce
– support all standards and payment protocols running
concurrently in the same environment
– Run everywhere (Netscape, IE, hand-held devices
– Reduce costs, efforts, and time
• Java commerce consists of the Java Electronic
Commerce Framework (JECF), which comprises
the related technologies of the Java Wallet and
Commerce Java Bean
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Java Wallet
• A family of products written in the JavaTM
programming language that are designed
to enable secure electronic commerce
operations
– Provides a single, unambiguous user
interface for electronic transaction
– The merchant offers goods or services for
sale on the WWW using applets which adhere
to the architecture built into the Java wallet
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Java Wallet
• Key concepts and components
– Gateway security model
• Foundation of the Java Wallet’s security
– Commerce JavaBeans
• Component that extend the JavaBean model
– Cassettes
• Designed Java archive (JAR) files that may contain
JavaBean as well as the resources required for their
operations
– Java Commerce Message
• A block of text sent from a commerce service to the user
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Java Wallet
• Exploit weakness in the Java Wallet
– Pickpocket
• An applet which steals information and passwords
from the Java wallet
– BookMarker
• An applet which alter the berhavior of the Java
Wallet
– DemonDialer
• An applet which can use your modem
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Java Wallet: Related Technologies
• Java Commerce API
– Provides foundation services that allow
developer to easily create new electronic
commerce application
• Rapid commerce component development
• Commerce JavaBeans Component
– A reusable commerce component that meets
specific interface requirements
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Rapid Application Development
• JavaBean technology is a significant
extension and enhancement of the Java
Language
– Enable programmer to rapidly build
applications by assembling objects and
testing them during design time
– AWT and Swing user interface classes are
JavaBean component
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RAD
• RAD is a software development technology
introduced in the 1980s
• It has been successfully and efficiently
implemented in development tools
– Visual Basic, Delphi, Power Builder, Oracle Developer
2000
• Using a RAD tool, projects can be developed
quickly and efficiently with minimum coding
• The key elements in a Java RAD tool are the
JavaBean components
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Swing Set Demo
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RAD with Swing Components
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Remote Method Invocation
• RMI is the Java Distributed Object Model for
facilitating communication among distributed
objects
– RMI technology provides a framework for building
distributed Java systems
– A Java object can invoke a method in an object on
another system on the network
• RMI is an evolution of the client/server
architecture
– A client is a component that issues requests for
services
– A server is a component that delivers the requested
services
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How Does RMI Work?
• The interface must extend the
java.rmi.Romote interface
• Steps
– The client send method parameters to the
server
– The server received the method parameter
and executes the method
– The server sends the result back to the client
– The client received the results
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How Does RMI Work?
Client
Server
Client
object
Server
stub
Return
Server Stub
Server
skeleton
RMI
registry
Server object
implementation
Register
Server object
Look for Server Object
Java RMI use a registry to provide naming services for remote objects, and use
The stub and skeleton to facilitate communications between client and server
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Stub and Skeleton
• Stub
– Resides on the client machine
– Contains all the reference information the client needs
to know about the server object
– Invokes a method that is encapsulated in the stub
– Is responsible for sending parameters to the server
and for receiving the result from the server and
returning it to the client
• Skeleton
–
–
–
–
Communicates with sthe stub on the server side
Receives parameters from the client
Passes them to the server for execution
Return the result to the stub
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Developing RMI in JBuilder
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Developing RMI in JBuilder
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Developing RMI in JBuilder
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Servlet
• Servlet technology is designed for use with the
HTTP protocol
• Servlets are Java programs that run on a Web
server
• CGI provides a simple approach for creating
dynamic Web applications
– Accept user request, process it on the server side,
and return responses to Web browser
– CGI is slow down when handling a large number of
request simultaneously, because the Web server
spawns a process for executing each CGI program
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Servlet
• Java Servlets are one of technologies
solving the problems
• Servlets are executed upon request from a
Web browser
– Run inside a servlet container
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