Java 2 Platform Enterprise EditionJ2EE

1
Java 2 Platform Enterprise Edition(J2EE) A Model
for Enterprise Application Development Report
from the Java Days ConferenceAthens,Greece
17/01/2002 Nikolaos Th. Korfiatis(nkorf_at_acm.org
)Research AssistantInformation Systems
Technologies LaboratoryDepartment of Management
Science and TechnologyAthens University of
Economics and Business Athens, Greece
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The Platform for Enterprise Solutions

• According to SUN the J2EE platform
• Represents a single standard for implementing and
  deploying enterprise applications.
• Has been designed through an open process.
• Is engaging a range of enterprise computing
  vendors, to ensure that it meets the widest
  possible range of enterprise application
  requirements.
• Addresses the core issues that impede
  organizations efforts to maintain a competitive
  place in the information economy.

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J2EE Architecture Overview

• The J2EE architecture is designed to provide
  server-side and client-side support for
• Developing enterprise, multitier applications.
• Providing client services and business logic for
  an application, and backend enterprise
  information systems
• Providing data and knowledge management.

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J2EE Platform Benefits

• With a set of features designed specifically to
  expedite the
• process of distributed application development,
  the J2EE
• platform offers several benefits such as
• Simplified architecture and development
• Scalability to meet demand variations
• Integration with existing information systems
• Choices of servers, tools, components
• Flexible security model

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Simplified Architecture and Development

• The J2EE platform supports a simplified,
  component-based development model.
• Because its based on the Java programming
  language and the Java 2 Platform, Standard
  Edition (J2SE TM platform), this model offers
  Write Once, Run Anywhere portability, supported
  by any server product that conforms to the J2EE
  standard.
• The component-based J2EE development model can
  enhance application development productivity in a
  number of ways

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Simplified Architecture and Development

• Maps easily to application functionality
• Component-based application models map easily and
  flexibly to the functionality desired from an
  application.
• Component-based design also simplifies
  application
• maintenance, since components can be
  updated and
• replaced independently new functionality
  can be shimmed into existing
  applications simply by updating selected
  components.

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Simplified Architecture and Development (2)

• Enables assembly- and deploy-time behaviors
• Components can expect the availability of
  standard services in the runtime environment, and
  can be dynamically connected to other components
  providing well-defined interfaces.
• As a result, many application behaviors can be
  configured at the time of application assembly or
  deployment, without any recoding required.

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Simplified Architecture and Development (3)

• Supports division of labor
• Components help divide the labor of application
  development among specific skill sets, enabling
  each member of a development team to focus on his
  or her ability.
• Thus, JSP templates can be created by graphic
  designers, their behavior by Java programming
  language coders, business logic by domain
  experts, and application assembly and deployment
  by the appropriate team members.
• This division of labor also helps expedite
  application maintenance.

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Integrating Existing Enterprise Information
Systems

• The J2EE platform, together with the J2SE
  platform, includes a number of industry standard
  APIs for access to existing enterprise
  information systems. Basic access to these
  systems is provided by the following APIs
• JDBC TM is the API for accessing relational data
  from Java.
• The Java Naming and Directory Interface TM (JNDI)
  is the API for accessing information in
  enterprise name and directory services.
• The Java Message Service (JMS) is the API for
  sending and receiving messages via enterprise
  messaging systems like IBM MQ Series and TIBCO
  Rendezvous.
• JavaMail TM is the API for sending and receiving
  email.
• Java IDL is the API for calling CORBA services.

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Support for Business Logic Components

• In the J2EE platform, middle-tier business logic
  is implemented in the middle tier as Enterprise
  JavaBeans components (also referred to as
  enterprise beans). Enterprise beans allow the
  component or application developer to concentrate
  on the business logic while the complexities of
  delivering a reliable, scalable service are
  handled by the EJB server.
• The J2EE platform and EJB architecture have
  complementary goals. The EJB component model is
  the backbone of the J2EE programming model. The
  J2EE plat-form complements the EJB specification
  by
• Fully specifying the APIs that an enterprise bean
  developer can use to implement enterprise beans.
• Defining the larger, distributed programming
  environment in which enterprise beans are used as
  business logic components.

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Scalability

• J2EE containers provide a mechanism that supports
  simplified scaling of distributed applications,
  without requiring any effort on the part of the
  application development team. Because J2EE
  containers provide components with transaction
  support, database connections, life cycle
  management, and other features that influence
  performance, they can be designed to provide
  scalability in these areas. This can achieved, by
  
• Providing database connection pooling so
  containers can ensure that clients will have
  access to data quickly.
• By allowing server providers freedom to configure
  containers to run on multiple systems. Web
  containers can be implemented to perform
  automatic load balancing as the demand for a
  particular application fluctuates.

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Choice of Servers, Tools, and Components

• The J2EE standard and J2EE brand are central to
  creating a marketplace for servers, tools, and
  components. The J2EE brand on a server product
  ensures the kind of ubiquity thats fundamental
  to the goals of the J2EE platform. In addition,
  J2EE
• standards ensure a lively marketplace for tools
  and components.
• A range of server choicesApplication
  development organizations can expect J2EE branded
  platforms from a variety of vendors, providing a
  range of choices in hardware platforms, operating
  systems, and server configurations. This ensures
  that businesses get a choice of servers
  appropriate to the strategic purpose of the
  applications they need.
• Designed for tool support
• Both EJB and JSP components are designed to be
  manipulated by graphical development tools, and
  to allow automating many of the application
  development tasks traditionally requiring the
  ability to write and debug code.

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Choice of Servers, Tools, and Components

• Both J2EE server providers and third-party
  tool developers can develop tools that conform to
  J2EE standards and support various application
  development tasks and styles. Application
  developers get a choice of tools to manipulate
  and assemble components, and individual team
  members may choose tools that suit their specific
  requirements best.
• A marketplace for componentsComponent-based
  design ensures that many types of behavior can be
  standardized, packaged, and reused by any J2EE
  application. Component vendors will provide a
  variety of off-the-shelf component solutions,
  including accounting beans, user interface
  templates, and even vertical market functionality
  of interest in specific industries. Application
  architects get a choice of standardized
  components to handle common or specialized tasks.

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Simplified, Unified Security Model

• The J2EE security model is designed to support
  single sign-on access to application services.
  Component developers can specify the security
  requirements of a component at the method level,
  to ensure that only users with appropriate
  permissions can access specific data operations.
• While the EJB and Java Servlet APIs both provide
  mechanisms for building security checks into
  code, the basic mechanism for matching users with
  roles (groups of users having specific
  permissions) is performed entirely at application
  deployment time. This provides both greater
  flexibility and better security control.

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Summary

• The challenge to IT professionals today is to
  efficiently develop and deploy distributed
  applications for use on both corporate intranets
  and over the Internet. Companies that can do this
  effectively will gain strategic advantage in the
  information economy.
• The Java 2 Platform, Enterprise Edition is a
  standard set of Java technologies that streamline
  the development, deployment, and management of
  enterprise applications. The J2EE platform is
  functionally complete in the sense that it is
  possible to develop a large class of enterprise
  applications using all the range of technologies
  that the java language can provide.

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References Resources

• http//www.sun.com/developers/evangcentralSUN
  Microsystems Technology Evangelists Main Page.
• http//Java.sun.comThe Java Language Reference.
• http//www.maxgoff.com
• Max Goff is a Technology Evangelist for Sun
  Microsystems, specializing in various Java
  technology-related topics.

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Java 2 Platform Enterprise Edition(J2EE) A Model
for Enterprise Application Development Report
from the Java Days ConferenceAthens,Greece
17/01/2002 Nikolaos Th. Korfiatis(nkorf_at_msn.co
m)Undergraduate StudentDepartment of
Management Science and TechnologyAthens
University of Economics and Business