An Overview of J2EE and WebServices

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An Overview of J2EE and WebServices

• Kinshuk Dutta

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Overview of J2EE

• J2EE supports the following technologies
• Extensible Markup Language
• Web Applications
• Web Services Support / WSDL Standard Format
• UDDI and ebXML Standard Formats
• HTTP-SOAP Transport Protocol
• J2EE comes with a built in application server

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XML

• J2EE defines Java API for XML Processing (JAXP)
  API for processing XML
• Uses SAX and DOM standarts

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Web Applications

• Java Servlets/JSP are part of the Suns J2EE
  Enterprise Architecture
• The web development part
• Java Servlet is a Common Gateway Interface (CGI)
  scripting technology
• CGI scripting is used to generate dynamic
  content.
• Java Servlet
• is a simple, consistent mechanism for extending
  the functionality of a web server
• Are precompiled Java programs that are executed
  on the server side.
• Require a Servlet container to run in
• Java Server Pages (JSP)
• A simplified, fast way to create dynamic web
  content
• HTML or XML pages with embedded Java Code or Java
  Beans
• Can be a mix of template data in HTML/XML with
  some dynamic content
• A JSP is a complied to a Java Servlet
  automatically by the Servlet container, it is
  then cached
• The main difference between JSP Servlets is
  basically that servlets are pre-compiled

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Web Services and J2EE

• Web services are built using Java API for
  XML-based RPC (JAX-RPC)
• RPC requests and responses are represented using
  SOAP 1.1
• Web service endpoints and clients use JAX-RPC
• Uses WSDL to describe web services

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How a web service is deployed?

• Has built in binaries
• to compile web
• services
• Has a user friendly
• Deploy Tool
• Services are deployed to Application Server
• Stubs, classes and WSDL are automatically
  generated from java files by precompiled
  binaries.

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Invoking a Web Service

• Three ways to design
• Static Stub
• Dynamic Proxy
• Dynamic Invocation Interface (DII)
• Problem Parsing WSDL file is not included in the
  standart API.
• Solution wsdl4j implementing Java Specification
  Request (JSR) 110

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J2EE and XML Registries

• Uses Java API for XML Registries (JAXR) to
  provide access to different kinds of XML
  Registries.
• Consists of a JAXR client and JAXR provider.

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HTTP SOAP

• SOAP with attachments (SAAJ) API is used
• Write SOAP messaging applications directly rather
  than using JAX-RPC
• Support SOAP 1.1

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EDMR Service
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EDMR Service Flow
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THE END

• THANKS!!!

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THE END

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