Enterprise Computing part 1

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Enterprise Computing part 1
Pierluigi Frisco
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Enterprise Computing part 1
Pierluigi Frisco
P.Frisco_at_exeter.ac.uk Tel [phone] Room 179
(only on appointment)
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Enterprise Computing

• EJB
• threads and synchronization
• security
• data warehousing
• communication substrates
• GRIDS computing.

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Enterprise Computing
assistant John R. Owen j.r.owen_at_ex.ac.uk
http//www.dcs.ex.ac.uk/studyRes/COM3510
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Enterprise Computing books
title Enterprise JavaBeans (4th edition) author
R. Monson-Haefel publisher OReilly
title Java Distributed Computing author J.
Farley publisher OReilly
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Enterprise JavaBeans (EJB)
A state-of-the-art architecture for developing,
deploying, and managing reliable enterprise
applications in production environments.
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Two-tier application architecture
PC
DB server
presentation logic
business logic
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Two-tier application architecture
advantages
easy to develop.
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Three-tier application architecture
Middle-tier server
Client Computer
DB server
presentation logic
business logic
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Three-tier application architecture
the middle-tier server improves scalability by
reusing expensive resources (database
connections) security is improved and
application management
advantages
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Early web-based application architecture
Web
Web server
CGI-bin scripts
web application
Common Gateway Interface
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CGI-bin scripts (Common Gateway Interface)
it is possible to write web-based applications
advantages
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J2EE application architecture (Java 2
Platform Enterprise Edition)
A standard architecture specifically oriented to
the development and deployment of enterprise
web-oriented applications using Java.
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J2EE application architecture Web-based
applications
Web server
EJB server
EJB container
Web container
RMI
Web application
enterprise bean
DB
client
internet
Web-EJB container
EJB container
local invocation
enterprise bean
Web application
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J2EE application architecture Web service
interactions
enterprise applications
J2EE .net Other
DB
Web SvC business logic
Internet or Intranet
EJB container
enterprise bean
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J2EE application architecture two-tier
applications
client
DB server
application-client container
presentation components
business logic
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J2EE application architecture three-tier
applications
client
business logic
DB
application-client container
EJB container
presentation components
enterprise bean
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J2EE application architecture three-tier
applications
advantages
simplicity application portability component
reusability separation of business logic from
representation logic easy development of Web
services
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Enterprise JavaBeans (EJB)
Managed server-side components for the modular
construction of enterprise applications.
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Enterprise JavaBeans (EJB)
Managed server-side components for the modular
construction of enterprise applications.
It means that EJB are distributed in binary
format and are configurable, so that the client
programmer can use them to create custom
applications.
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Enterprise JavaBeans (EJB)
Managed server-side components for the modular
construction of enterprise applications.
It means that EJB objects are allocated in a
process on some server, not on the client
machine. EJB can offer remote view, local view,
or both.
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Enterprise JavaBeans (EJB)
Managed server-side components for the modular
construction of enterprise applications.
It means that when a EJB object is active in
memory, its hosting process (the EJB container)
provides management functionalities.
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Remote Method Invocation (RMI) loop
Client Network Middle tier
skeleton
server object
stub
5) return result
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Container
EJB server
EJB container
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EJB containers

• object persistence
• declarative security control
• declarative transaction control
• concurrency management
• scalability management.

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Our imaginary business
? ? ?
Titan Cruises