Developing Web Services with the Eclipse Web Tools Platform

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Developing Web Services with the Eclipse Web
Tools Platform

• David Gallardo

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My books

• Java Oracle Database Development
• Eclipse in Action, (lead author)
• Eclipse in Action, 2nd edition due out in
  December
• Preview article, Introducing the Eclipse Visual
  Editor available at
• http//www.manning.com/books/gallardo2

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This presentation available at

• http//www.gallardo.org

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What are Web Services?

• Extend the WWW from The Web for eyeballs to
  The Web for programs
• Move from Business2User to Business2Business
• Language/platform neutral remote procedure calls
  built on HTTP infrastructure

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Locating a web service
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Locating a web service
Publish WSDL
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Locating a web service
Query for service
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Locating a web service
Obtain WSDL
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Using a web service
Call web service operation
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Using a web service
Receive result
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Web services alphabet soup
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Fundamental standards and technologies

• XML eXtensible Markup Language The syntax used
  for Web Service messages, configuration files,
  description files, etc.
• HTTP Hypertext Transfer Protocol The standard
  transport used to communicate between Web Service
  servers and clients
• RPC Remote Procedure Call The technique of
  executing a method call remotelyhere, the client
  calling a web services operation.

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Web Service standards and technologies

• SOAP Simple Object Access Protocol. An
  XML-based standard for sending messages (in a
  SOAP envelope) between web services and clients.
• WSDLWeb Service Definition Language XML-based
  description of a web services public interface.
  (Similar to CORBA IDL.)
• UDDIUniversal Description, Discovery and
  Integration. And XML-based registry for web
  service. Interrogated with SOAP messages, returns
  WSDL documents.

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Eclipse Web Services Platform

• Provides tools for
• Web applications using JSP/servlets
• EJB
• Web Service (based on Apache AXIS)
• Database exploration

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Java Web Service related protocols

• JAXPJava API for XML Processing
• JAX-RPCJava API for XML-based RPC
• JAXRJava API for XML registries
• SAAJSOAP with Attachments API for Java
• SAXSimple API for XML processing
• DOM APIDocument Object Model API

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The rest

• We wont worry about these for now
• DIMEDirect Internet Message Encapsulation
• HTTPRReliable HTTP
• WSCLWeb Services Conversation Language
• WSCMWeb Services Component Model
• WSELWeb Services Endpoint Language
• WSFLWeb Services Flow Language
• WSMLWeb Services Meta Language
• WSXL-Web Services Experience Language
• WSUIWeb Services User Interface
• XLANGWeb Services for Business Process Design
• USMLUDDI Search Markup Language

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Eclipse WTP tools for developing a Web Service

• Top down
• You write the WSDL
• Eclipse creates the necessary glue classes and
  the services method stubs in a Java Bean
• You implement the operations
• Bottom up
• You create the web service Java Bean
• Eclipse creates the glue classes and the WSDL

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Demo

• Install WTP from Eclipse.org update site.
• Create a web service, bottom-up
• Exploring a Web Service using the Web Services
  Explorer (ideally http//www.xmethods.com, but
  here well just use the service we created.)
• Creating a web client for the GoogleAPI web
  service with WTP.
• Writing our own client.