Academic Tutorials



English | French | Portugese | German | Italian
Home Advertise Payments Recommended Websites Interview Questions FAQs
News Source Codes E-Books Downloads Jobs Web Hosting
Chats

EJB Tutorial
EJB introduction
EJB container
EJB Types
Sessions in EJB
EJB entity
EJB message driven
EJB Constitutes
EJB example
EJB deploy
EJB summary

HTML Tutorials
HTML Tutorial
XHTML Tutorial
CSS Tutorial
TCP/IP Tutorial
CSS 1.0
CSS 2.0
HLML
XML Tutorials
XML Tutorial
XSL Tutorial
XSLT Tutorial
DTD Tutorial
Schema Tutorial
XForms Tutorial
XSL-FO Tutorial
XML DOM Tutorial
XLink Tutorial
XQuery Tutorial
XPath Tutorial
XPointer Tutorial
RDF Tutorial
SOAP Tutorial
WSDL Tutorial
RSS Tutorial
WAP Tutorial
Web Services Tutorial
Browser Scripting
JavaScript Tutorial
VBScript Tutorial
DHTML Tutorial
HTML DOM Tutorial
WMLScript Tutorial
E4X Tutorial
Server Scripting
ASP Tutorial
PERL Tutorial
SQL Tutorial
ADO Tutorial
CVS
Python
Apple Script
PL/SQL Tutorial
SQL Server
PHP
.NET (dotnet)
Microsoft.Net
ASP.Net
.Net Mobile
C# : C Sharp
ADO.NET
VB.NET
VC++
Multimedia
SVG Tutorial
Flash Tutorial
Media Tutorial
SMIL Tutorial
Photoshop Tutorial
Gimp Tutorial
Matlab
Gnuplot Programming
GIF Animation Tutorial
Scientific Visualization Tutorial
Graphics
Web Building
Web Browsers
Web Hosting
W3C Tutorial
Web Building
Web Quality
Web Semantic
Web Careers
Weblogic Tutorial
SEO
Web Site Hosting
Domain Name
Java Tutorials
Java Tutorial
JSP Tutorial
Servlets Tutorial
Struts Tutorial
EJB Tutorial
JMS Tutorial
JMX Tutorial
Eclipse
J2ME
JBOSS
Programming Langauges
C Tutorial
C++ Tutorial
Visual Basic Tutorial
Data Structures Using C
Cobol
Assembly Language
Mainframe
Forth Programming
Lisp Programming
Pascal
Delphi
Fortran
OOPs
Data Warehousing
CGI Programming
Emacs Tutorial
Gnome
ILU
Soft Skills
Communication Skills
Time Management
Project Management
Team Work
Leadership Skills
Corporate Communication
Negotiation Skills
Database Tutorials
Oracle
MySQL
Operating System
BSD
Symbian
Unix
Internet
IP-Masquerading
IPC
MIDI
Software Testing
Testing
Firewalls
SAP Module
ERP
ABAP
Business Warehousing
SAP Basis
Material Management
Sales & Distribution
Human Resource
Netweaver
Customer Relationship Management
Production and Planning
Networking Programming
Corba Tutorial
Networking Tutorial
Microsoft Office
Microsoft Word
Microsoft Outlook
Microsoft PowerPoint
Microsoft Publisher
Microsoft Excel
Microsoft Front Page
Microsoft InfoPath
Microsoft Access
Accounting
Financial Accounting
Managerial Accounting
Network Sites


EJB Constitutes


Previoushome Next





Constitutes an EJB


Building an EJB requires assembling the correct component parts. These include interfaces and deployment descriptors.


A D V E R T I S E M E N T



EJB Interfaces

  • All bean classes must implement javax.ejb.EnterpriseBean, or one of its subinterfaces, at some level.

    • javax.ejb.EnterpriseBean extends java.io.Serializable.
  • Session beans implement javax.ejb.SessionBean.
    • javax.ejb.SessionBean extends javax.ejb.EnterpriseBean.
    • It defines methods: ejbActivate, ejbPassivate, ejbRemove, and setSessionContext.

  • Entity Beans implement javax.ejb.EntityBean.
    • javax.ejb.EntityBean extends javax.ejb.EnterpriseBean.
    • It defines methods: ejbActivate, ejbPassivate, ejbRemove, setEntityContext, ejbLoad, ejbStore, and unsetEntityContext.

  • Message Driven Beans implement javax.ejb.MessageDrivenBean.
    • javax.ejb.MessageDrivenBean extends javax.ejb.EnterpriseBean.

    • It defines methods: ejbRemove and setMessageDrivenContext.



What Constitutes an EJB?

EJB Object

Client never invokes methods directly on an actual bean instance. All invocations go through the EJB object, which is a tool-generated class. Message requests are intercepted by the EJB object and then delegated to the actual bean instance. That is why it is called a request interceptor.

Remote Interface

A bean class exposes business methods that are cloned by the EJB object. But how do the tools that generate the EJB object know which methods to clone? The answer is the remote interface. This interface duplicates all the methods that the corresponding bean class exposes (remember that they must comply with the EJB specification). Remote clients then access the bean via this remote interface. All remote interfaces must extend javax.ejb.EJBObject.

Home Object

How do clients acquire references to EJB objects? The client asks for the EJB object from the EJB object factory. This factory is responsible for instantiating and destroying the EJB objects. This factory is called the Home object.

Home Interface

How does a home object know how you would like to initialize your EJB object? This information is provided to the container through the home interface. The home interface contains the methods for creating, destroying, and finding EJB objects. All home interfaces are derived from the javax.ejb.EJBHome interface and all home objects implement the home interface. This interface extends java.rmi.Remote.

Local Interfaces

Creating beans through the home interface and then calling the beans though the remote interface is very slow. Local interfaces speed up beans' calls. Use local objects (implemented from a local interface rather than from a remote interface) instead of EJB objects whenever possible. Also, use local home objects (implemented from a local home interface rather than from a home interface) instead of home objects. Local interfaces extend javax.ejb.EJBLocalObject and local home interfaces extend javax.ejb.EJBLocalHome.

Deployment Descriptors

You state your deployment configuration in the deployment descriptor file named ejb-jar.xml. Different application servers may have their own additional proprietary deployment descriptor files. These XML files can either be edited by hand or with a tool provided by the container vendor. You can specify:

  • Bean management and lifecycle requirements.

  • Persistence requirements for entity beans.

  • Transaction requirements.

  • Security requirements, including access control entries.

EJB-JAR file

Once you have finished compiling your classes and creating all of the necessary configuration files, you can place all of these files into an EJB-JAR file for deployment. EJB-JAR files are zip files that contain Java classes and all the other files needed for deployment. You can generate these files by hand or with tools, such as Apache Ant.



Be the first one to comment on this page.




  EJB Tutorial eBooks

No eBooks on EJB could be found as of now.

 
 EJB Tutorial FAQs
More Links » »
 
 EJB Tutorial Interview Questions
More Links » »
 
 EJB Tutorial Articles

No EJB Articles could be found as of now.

 
 EJB Tutorial News

No News on EJB could be found as of now.

 
 EJB Tutorial Jobs

No EJB Articles could be found as of now.


Share And Enjoy:These icons link to social bookmarking sites where readers can share and discover new web pages.
  • blinkbits
  • BlinkList
  • blogmarks
  • co.mments
  • connotea
  • del.icio.us
  • De.lirio.us
  • digg
  • Fark
  • feedmelinks
  • Furl
  • LinkaGoGo
  • Ma.gnolia
  • NewsVine
  • Netvouz
  • RawSugar
  • Reddit
  • scuttle
  • Shadows
  • Simpy
  • Smarking
  • Spurl
  • TailRank
  • Wists
  • YahooMyWeb

Previoushome Next

Keywords: EJB Constitutes,ejb sample code,ejb web services,open source ejb,weblogic 8.1 ejb,ejb session bean,web service ejb,ejb tutorial,ejb tutorials,ejb overview,ejb examples,ejb java,ejb faq,tomcat ejb,ejb introduction,ejb api

HTML Quizzes
HTML Quiz
XHTML Quiz
CSS Quiz
TCP/IP Quiz
CSS 1.0 Quiz
CSS 2.0 Quiz
HLML Quiz
XML Quizzes
XML Quiz
XSL Quiz
XSLT Quiz
DTD Quiz
Schema Quiz
XForms Quiz
XSL-FO Quiz
XML DOM Quiz
XLink Quiz
XQuery Quiz
XPath Quiz
XPointer Quiz
RDF Quiz
SOAP Quiz
WSDL Quiz
RSS Quiz
WAP Quiz
Web Services Quiz
Browser Scripting Quizzes
JavaScript Quiz
VBScript Quiz
DHTML Quiz
HTML DOM Quiz
WMLScript Quiz
E4X Quiz
Server Scripting Quizzes
ASP Quiz
PERL Quiz
SQL Quiz
ADO Quiz
CVS Quiz
Python Quiz
Apple Script Quiz
PL/SQL Quiz
SQL Server Quiz
PHP Quiz
.NET (dotnet) Quizzes
Microsoft.Net Quiz
ASP.Net Quiz
.Net Mobile Quiz
C# : C Sharp Quiz
ADO.NET Quiz
VB.NET Quiz
VC++ Quiz
Multimedia Quizzes
SVG Quiz
Flash Quiz
Media Quiz
SMIL Quiz
Photoshop Quiz
Gimp Quiz
Matlab Quiz
Gnuplot Programming Quiz
GIF Animation Quiz
Scientific Visualization Quiz
Graphics Quiz
Web Building Quizzes
Web Browsers Quiz
Web Hosting Quiz
W3C Quiz
Web Building Quiz
Web Quality Quiz
Web Semantic Quiz
Web Careers Quiz
Weblogic Quiz
SEO Quiz
Web Site Hosting Quiz
Domain Name Quiz
Java Quizzes
Java Quiz
JSP Quiz
Servlets Quiz
Struts Quiz
EJB Quiz
JMS Quiz
JMX Quiz
Eclipse Quiz
J2ME Quiz
JBOSS Quiz
Programming Langauges Quizzes
C Quiz
C++ Quiz
Visual Basic Quiz
Data Structures Using C Quiz
Cobol Quiz
Assembly Language Quiz
Mainframe Quiz
Forth Programming Quiz
Lisp Programming Quiz
Pascal Quiz
Delphi Quiz
Fortran Quiz
OOPs Quiz
Data Warehousing Quiz
CGI Programming Quiz
Emacs Quiz
Gnome Quiz
ILU Quiz
Soft Skills Quizzes
Communication Skills Quiz
Time Management Quiz
Project Management Quiz
Team Work Quiz
Leadership Skills Quiz
Corporate Communication Quiz
Negotiation Skills Quiz
Database Quizzes
Oracle Quiz
MySQL Quiz
Operating System Quizzes
BSD Quiz
Symbian Quiz
Unix Quiz
Internet Quiz
IP-Masquerading Quiz
IPC Quiz
MIDI Quiz
Software Testing Quizzes
Testing Quiz
Firewalls Quiz
SAP Module Quizzes
ERP Quiz
ABAP Quiz
Business Warehousing Quiz
SAP Basis Quiz
Material Management Quiz
Sales & Distribution Quiz
Human Resource Quiz
Netweaver Quiz
Customer Relationship Management Quiz
Production and Planning Quiz
Networking Programming Quizzes
Corba Quiz
Networking Quiz
Microsoft Office Quizzes
Microsoft Word Quiz
Microsoft Outlook Quiz
Microsoft PowerPoint Quiz
Microsoft Publisher Quiz
Microsoft Excel Quiz
Microsoft Front Page Quiz
Microsoft InfoPath Quiz
Microsoft Access Quiz
Accounting Quizzes
Financial Accounting Quiz
Managerial Accounting Quiz
Testimonials | Contact Us | Link to Us | Site Map
Copyright 2008. Academic Tutorials.com. All rights reserved Privacy Policies | About Us
Our Portals : Academic Tutorials | Best eBooksworld | Beyond Stats | City Details | Interview Questions | Discussions World | Excellent Mobiles | Free Bangalore | Give Me The Code | Gog Logo | Indian Free Ads | Jobs Assist | New Interview Questions | One Stop FAQs | One Stop GATE | One Stop GRE | One Stop IAS | One Stop MBA | One Stop SAP | One Stop Testing | Webhosting in India | Dedicated Server in India | Sirf Dosti | Source Codes World | Tasty Food | Tech Archive | Testing Interview Questions | Tests World | The Galz | Top Masala | Vyom | Vyom eBooks | Vyom International | Vyom Links | Vyoms | Vyom World
Copyright 2003-2019 Vyom Technosoft Pvt. Ltd., All Rights Reserved.