Ejb Websevice Presentation

8/8/2019 Ejb Websevice Presentation

http://slidepdf.com/reader/full/ejb-websevice-presentation 1/20

Expose an Stateless Session BeanExpose an Stateless Session Beanas a Web Serviceas a Web Service

Jaliya EkanayakeJaliya Ekanayake



Agenda Agenda

Few DefinitionsFew Definitions

The Basics of Web ServicesThe Basics of Web Services

Benefits of Web ServicesBenefits of Web Services

Simple Web Service ExampleSimple Web Service Example

What is available in J2EE TechnologyWhat is available in J2EE Technology

EJB Web ServicesEJB Web Services

Exposing an EJB as a Web ServiceExposing an EJB as a Web Service

Tools Support Tools Support

Best PracticesBest Practices Sample ScenarioSample Scenario



Web ServicesWeb Services -- BasicsBasics

DefinitionsDefinitions

Web service is a software application identified by a URI [RFC 2396],Web service is a software application identified by a URI [RFC 2396],whose interfaces and bindings are capable of being defined, described,whose interfaces and bindings are capable of being defined, described,and discovered as XML artifacts. A Web service supports direct interactionsand discovered as XML artifacts. A Web service supports direct interactionswith other software agents using XML based messages exchanged viawith other software agents using XML based messages exchanged viaInternet Internet--based protocols.based protocols. W3CW3C

Web servicesWeb services----software components that are programmatically accessiblesoftware components that are programmatically accessibleover standard Internet protocolsover standard Internet protocols Java Blue PrintsJava Blue Prints

Web Services in 2005Web Services in 2005

But ultimately what I really expect in this coming years that that Web But ultimately what I really expect in this coming years that that Webservices will go from that thing that you have tried once or twice, to anservices will go from that thing that you have tried once or twice, to anintegral part of almost all your development projects.integral part of almost all your development projects. --Matt Powell theMatt Powell thecontent strategist at the MSDN Web Services Developer Center.content strategist at the MSDN Web Services Developer Center.



The ModelThe Model

SO AP HandlerSO AP Handler

Takes the parameters from the native client address space and transform (serialize)Takes the parameters from the native client address space and transform (serialize)then to SO AP.then to SO AP.

Takes the SO AP from the network and transform (deTakes the SO AP from the network and transform (de--serialize) it to parameters of serialize) it to parameters of the native service address space.the native service address space.

SO AP Handler may accept SO AP messages sent on various transport protocols.SO AP Handler may accept SO AP messages sent on various transport protocols.

E.g. HTTP, SMTP, TCP etc..E.g. HTTP, SMTP, TCP etc..

HTTP is the most popular protocolHTTP is the most popular protocol

Client

SOAP

Handler Client

Network

Server

SOAP

Handler ServiceSOAP msg SOAP msg

The Web Services Model



Benefits of Web ServicesBenefits of Web Services

Interoperabilit y in a heterogeneous environment Interoperabilit y in a heterogeneous environment

Business services through the WebBusiness services through the Web

Integration with existing systemsIntegration with existing systems


Support more client t ypesSupport more client t ypes Programming productivit y Programming productivit y



Simplest way is to use JSE(J AX Simplest way is to use JSE(J AX--RPC Service Endpoint)RPC Service Endpoint) Expose Java classes directly as web servicesExpose Java classes directly as web services

Can use SO AP Endpoints based on Servlet Containers, e.g. Apache AxisCan use SO AP Endpoints based on Servlet Containers, e.g. Apache Axis

E.g. JSE with SO AP over HTTPE.g. JSE with SO AP over HTTP

Example Using Apache AxisExample Using Apache Axis

The Code Snippet for the ServiceThe Code Snippet for the Service >>>>

The Code Snippet for the client The Code Snippet for the client >>>>

DemoDemo

Simple Web Service ExampleSimple Web Service Example

SOAP

Handler

Service

Servlet Container

SOAP

Over HTTP

JAX-RPC Service Endpoint with SOAP Over HTTP



What is available in J2EE TechnologyWhat is available in J2EE Technology

EJB components, by design, are meant for distributed computingEJB components, by design, are meant for distributed computing

EJB components are scalable, transactional, and secureEJB components are scalable, transactional, and secure

J2EE Containers provide primary services such as Naming, Login, Transaction,J2EE Containers provide primary services such as Naming, Login, Transaction,Deployment and Securit yDeployment and Securit y

Developer can focus more on Business LogicsDeveloper can focus more on Business Logics

Tons of applications have already bean written using EJBsTons of applications have already bean written using EJBs

Web Browser, Appletsand optionally

Java BeanComponents

Application Clients(Java)

Client Tier

J2EE Server

Web Tier Business Tier

JSPsand Servlets

Session BeansEntity Beans

Message DrivenBeans

EIS Tier

DB

RMIor IIOP

HTTP

J2EE Architecture



EJB Web Services (JSR 109)EJB Web Services (JSR 109)

J2EE 1.4 Allows J AX J2EE 1.4 Allows J AX--RPC (JSR 101) Web Services using Stateless SessionRPC (JSR 101) Web Services using Stateless Session

Beans.Beans. J AX J AX--RPC hides the complexit y of SO AP messages from the developer.RPC hides the complexit y of SO AP messages from the developer.

J2EE web services can be invoked by any web service client, and any J2EEJ2EE web services can be invoked by any web service client, and any J2EEweb service client can invoke any web service.web service client can invoke any web service.

Web Browser, Appletsand optionally

Java BeanComponents

Application Clients(Java)

Application Clients(Java/Non Java)

Client Tier J2EE Server

Web Tier Business Tier

JSPsand Servlets

Session BeansEntity Beans

Message DrivenBeans

EIS Tier

DB

SOAPHandler SOAP

RMIor IIOP

HTTP

Web Services in J2EE



Exposing an Stateless EJB as a Web ServiceExposing an Stateless EJB as a Web Service

Simple StepsSimple Steps Define the service interface (Depending on the business functionalit y that needs toDefine the service interface (Depending on the business functionalit y that needs to

be exposed)be exposed) >>>>

Generate the WSDL for the above service end point Generate the WSDL for the above service end point >>>>

E.g. Using Java2WSDL from ApacheE.g. Using Java2WSDL from Apache

java org.apache.axis.wsdl.Java2WSDLjava org.apache.axis.wsdl.Java2WSDL --aa --oo"CardValidatorService.wsdl""CardValidatorService.wsdl" --n "urn:ejbn "urn:ejb--ws"ws" --ll

"REPLACE_WITH_ACTUAL_URL" test.ejb.CardValidatorService"REPLACE_WITH_ACTUAL_URL" test.ejb.CardValidatorService

Create or Generate J AX Create or Generate J AX--RPC Mapping fileRPC Mapping file >>>>

Add the WSDL J AX Add the WSDL J AX--RPC Mapping file to the Manifest RPC Mapping file to the Manifest

Modif y the ejbModif y the ejb--jar.xml jar.xml >>>>

Add webservices.xml Add webservices.xml >>>> Package and DeployPackage and Deploy

DemoDemo

Accessing the web service can be done by J2EE, J2SE, J2ME or any other Accessing the web service can be done by J2EE, J2SE, J2ME or any otherclients that are running on different platforms.clients that are running on different platforms.




Servers that support JSR109Servers that support JSR109

SunSun JavaJava SystemSystem Application Application Server Platform Edition 8.1Server Platform Edition 8.1

JBOSSJBOSS--4.0.1RC14.0.1RC1

Oracle Application Server Containers for J2EE (OC4J) 10.0.3Oracle Application Server Containers for J2EE (OC4J) 10.0.3

Sun ONE (Open Network Environment) Application ServerSun ONE (Open Network Environment) Application Server

IBM Websphere V6IBM Websphere V6

Weblogic Server 7.0Weblogic Server 7.0

Apache Geronimo Apache Geronimo

IDEs and other toolsIDEs and other tools

Eclipse + Lomboz+ Jboss (Open source tool set)Eclipse + Lomboz+ Jboss (Open source tool set)

IBM WebSphere StudioIBM WebSphere Studio

SunSun JavaJava SystemSystem Application Application Server Platform Edition 8.1Server Platform Edition 8.1



Best PracticesBest Practices

Services should be coarse grainServices should be coarse grain Avoid overusing Web services in your applications Avoid overusing Web services in your applications

Design your Web service so that it creates minimal network traffic >>Design your Web service so that it creates minimal network traffic >>

Avoid maintaining any kind of state information in your EJB components that Avoid maintaining any kind of state information in your EJB components that are exposed as Web services.are exposed as Web services.

Use J AX Use J AX--RPC data t ypes as the method parameters for the Web service toRPC data t ypes as the method parameters for the Web service togive it interoperabilit y with heterogeneous Web servicesgive it interoperabilit y with heterogeneous Web services

Avoid t ypes such as Collection, HashMap, and Lists as parameters for your Avoid t ypes such as Collection, HashMap, and Lists as parameters for yourWeb service if interoperabilit y is important for your applicationWeb service if interoperabilit y is important for your application

Avoid exposing an EJB component that involves long Avoid exposing an EJB component that involves long--running transactions asrunning transactions asa Web service.a Web service.

Weigh the securit y requirements against performance, because securit y Weigh the securit y requirements against performance, because securit y comes with a higher cost. The performance costs of endcomes with a higher cost. The performance costs of end--toto--end securit y areend securit y arehigh.high.



K nown Limitations and IssuesK nown Limitations and Issues

Some Web Service Standards are still in draft levelSome Web Service Standards are still in draft level

May degrade the performance if used incorrectlyMay degrade the performance if used incorrectly

Possible securit y threats (SO AP over HTTP)Possible securit y threats (SO AP over HTTP)

Interoperabilit y issues (WSInteroperabilit y issues (WS--I Basic Profile)I Basic Profile)

Matching RequirementsMatching Requirements



Sample ScenarioSample Scenario



SummarySummary

Basics of Web ServicesBasics of Web Services

What is already there in J2EEWhat is already there in J2EE

How to expose an EJB as a Web ServiceHow to expose an EJB as a Web Service

Best PracticesBest Practices



ReferencesReferences

JBOSS DocumentationJBOSS Documentation

http://docs.jboss.org /jbossas/getting_started/start guide40/ws.htmlhttp://docs.jboss.org /jbossas/getting_started/start guide40/ws.html

Designing Web Services with the J2EE 1.4 Platform: J AX Designing Web Services with the J2EE 1.4 Platform: J AX--RPC, SO AP, and XMLRPC, SO AP, and XMLTechnologiesTechnologies

http://java.sun.com/blueprints/guidelines/designing_webservices/http://java.sun.com/blueprints/guidelines/designing_webservices/

Web Services for J2EE, Version 1.0 (JSR109)Web Services for J2EE, Version 1.0 (JSR109)

ftp://wwwftp://www--126.ibm.com/pub/jsr109/spec/1.0/websvcs126.ibm.com/pub/jsr109/spec/1.0/websvcs--1 _01 _0--fr.pdf fr.pdf

Tutorial for building J2EE Applications using JBOSS and ECLIPSETutorial for building J2EE Applications using JBOSS and ECLIPSE

http://www.tusc.com.au/tutorial/html/chap1.htmlhttp://www.tusc.com.au/tutorial/html/chap1.html

http://www.javaworld.com/javaworld/jwhttp://www.javaworld.com/javaworld/jw--0808--2004/jw2004/jw--08020802--ejbws.htmlejbws.html

http://publib.boulder.ibm.com/infocenter/iadthelp/index.jsp?topic=/com.ibm.etools.webshttp://publib.boulder.ibm.com/infocenter/iadthelp/index.jsp?topic=/com.ibm.etools.webservice.doc/concepts/cjsr109.htmlervice.doc/concepts/cjsr109.html

http://dev2dev.bea.com/products/wlserver/articles/Gilbode.jsphttp://dev2dev.bea.com/products/wlserver/articles/Gilbode.jsp

http://incubator.apache.org /projects/geronimo/http://incubator.apache.org /projects/geronimo/

http://java.sun.com/developer/technical Articles/J2EE/j2ee _ws/#designhttp://java.sun.com/developer/technical Articles/J2EE/j2ee _ws/#design



Thank YouThank You



CardValidator Web Service (JSE)CardValidator Web Service (JSE)

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Web service endpoint for the stateless EJBWeb service endpoint for the stateless EJB

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ejbejb--jar.xml jar.xml

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Ejb Websevice Presentation

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