Geospatial Web Services Introduction to Geospatial Web Services
Web services
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Java Web ServicesJava Web Services CSCI 4300CSCI 4300
Diagrams from the Sun Java Web Services Diagrams from the Sun Java Web Services Tutorial,Tutorial,
http://java.sun.com/webservices/docs/1.6/tutorial/doc/http://java.sun.com/webservices/docs/1.6/tutorial/doc/
What are Web Services?What are Web Services?
• Business-to-Business (B2B) communication• Packaged in XML “SOAP” messages
Example: Travel AgentExample: Travel Agent
Service-Oriented Architecture Service-Oriented Architecture (SOA)(SOA)
Needs:1. Mechanism for discovering services (registry)2. Language for specifying service contract (Web
service semantic)
Simple Object Access Protocol Simple Object Access Protocol (SOAP)(SOAP)
• Envelope: top-level element, represents entire message
• Header: optional info to guide delivery and processing by multiple actors, e.g. shipping, logging, accounting
• Body: contains request / response info
• Fault: carries error messages
<?xml version="1.0"?<soap:Envelope xmlns:soap=…"> <soap:Header> ... ... </soap:Header> <soap:Body> ... ... <soap:Fault> ... ... </soap:Fault> </soap:Body>
</soap:Envelope>
Interfacing SOAP with Proprietary Interfacing SOAP with Proprietary business processbusiness process
Example: SOAP over AJAX Example: SOAP over AJAX
• Using a “WS” package to handle SOAP encoding
XHttpRequest lifecycleXHttpRequest lifecycle
Java XML Binding (JAXB)Java XML Binding (JAXB)
• Marshalling: collecting data into XML• Binding: generating Java classes to represent
XML
How Binding WorksHow Binding Works
Old-school remote Java: RMIOld-school remote Java: RMI
Remote Java using Web Services Remote Java using Web Services Model (JAX-RPC)Model (JAX-RPC)
Another View of JAX-RPCAnother View of JAX-RPC
• This shows the JAX-RPC runtime and HTTP/SOAP transport
• In this case client and server are both Java
Yet Another ViewYet Another View
• Showing the role of WSDL to coordinate client and server
• In his case the client is not necessarily in Java!
Java XML Registry (JAXR)Java XML Registry (JAXR)
• Java API overlaid on native registry systems • A registry allows location of objects
WSDL (Fujitsu version)WSDL (Fujitsu version)
WSDL (Sun version)WSDL (Sun version)
UDDI ArchitectureUDDI Architecture
AcknowledgementsAcknowledgements
• Webservices strategy: http://www.webservices-strategy.com/
• SOAP/proprietary interface: http://www.ebizq.net• SOAP over AJAX diagrams:
http://www.ibm.com/developerworks/webservices/library/ws-wsajax/
• Web services architecture:
http://www.w3.org/2003/Talks/0317-ws-intro/• Fujitsu WDSL diagram: xml.fujitsu.com
• RPC diagrams: http://www.onjava.com/pub/a/onjava/2002/04/24/jax-rpc.html
• “Figure 1”: http://dev2dev.bea.com/lpt/a/345
• JAX-J2EE: www.vsj.co.uk