Web Services Web Services Overview Overview Dr. Kanda Runapongsa - PDF document

Java Web Services, Software Park Thailand, 2004 Web Services Web Services Overview Overview Dr. Kanda Runapongsa Dr. Kanda Runapongsa Department of Computer Engineering Department of Computer Engineering Khon Kaen University Khon Kaen University 1 Outline Outline � What is Web Services? What is Web Services? � � Why Web Services? Why Web Services? � � Where is Web Services? Where is Web Services? � � Web Services Architecture and Standards Web Services Architecture and Standards � � Web Services Implementation and Tools Web Services Implementation and Tools � 2 Dr. Kanda Runapongsa, Khon Kaen University 1

Java Web Services, Software Park Thailand, 2004 In Search of a Definition In Search of a Definition � Web Services mean different things to Web Services mean different things to � different people different people � Web Services == Web Application? Web Services == Web Application? � Web Services � � Computer to Computer Computer to Computer � Web Services � � Web Application Web Application � � Computer to Human beings Computer to Human beings � � Web Services == e Web Services == e- -Commerce? Commerce? � � E E- -Commerce needs to also consider security Commerce needs to also consider security � 3 Web Services Definition by W3C Web Services Definition by W3C � A Web service is a A Web service is a software application software application � identified by a URI a URI identified by � Support direct Support direct interactions with other interactions with other � software applications software applications � Using Using XML based messages XML based messages via via � Internet- -based protocols based protocols Internet 4 Dr. Kanda Runapongsa, Khon Kaen University 2

Java Web Services, Software Park Thailand, 2004 Distributed Computing Evolution Distributed Computing Evolution 5 Traditional RPC vs. Web Services Traditional RPC vs. Web Services 6 Dr. Kanda Runapongsa, Khon Kaen University 3

Java Web Services, Software Park Thailand, 2004 Web Application vs. Web Services Web Application vs. Web Services 7 Characteristics of Web Services Characteristics of Web Services � XML based everywhere XML based everywhere � � Message Message- -based based � � Programming language independent Programming language independent � � Could be dynamically located Could be dynamically located � � Could be dynamically assembled or aggregated Could be dynamically assembled or aggregated � � Accessed over the internet Accessed over the internet � � Loosely coupled Loosely coupled � � Based on industry standards Based on industry standards � 8 Dr. Kanda Runapongsa, Khon Kaen University 4

Java Web Services, Software Park Thailand, 2004 Service Aggregation Service Aggregation SetTrade Input: Symbol Output: Price Stock Service Portal User Input: Symbol News feed 1 Output: Price, News, Input: Symbol Trade Output: News links … Brokerage 1 Brokerage n News feed n Input: Symbol, Input: Symbol, .. Input: Symbol Price, Qty Price, Qty Output: News links Output: Analysis Output: Analysis 9 Outline Outline � What is Web Services? What is Web Services? � � Why Web Services? Why Web Services? � � Where is Web Services? Where is Web Services? � � Web Services Architecture and Standards Web Services Architecture and Standards � � Web Services Implementation and Tools Web Services Implementation and Tools � 10 Dr. Kanda Runapongsa, Khon Kaen University 5

Java Web Services, Software Park Thailand, 2004 Why Web Services? Why Web Services? Platform neutral � Platform neutral � Accessible in a standard way � Accessible in a standard way � Accessible in an interoperable way � Accessible in an interoperable way � Use simple and ubiquitous tools � Use simple and ubiquitous tools � Relatively cheap � Relatively cheap � Simplify enterprise integration � Simplify enterprise integration � 11 Why Web Services? Why Web Services? � Interoperable Interoperable – – Connect across heterogeneous Connect across heterogeneous � networks using ubiquitous web- networks using ubiquitous web -based standards based standards � Economical Economical – – Recycle components, no installation Recycle components, no installation � and tight integration of software and tight integration of software � Automatic Automatic – – No human intervention required even for No human intervention required even for � highly complex transactions highly complex transactions � Accessible Accessible – – Legacy assets & internal apps are exposed Legacy assets & internal apps are exposed � and accessible on the web and accessible on the web � Available Available – – Services on any device, anywhere, anytime Services on any device, anywhere, anytime � � Scalable Scalable – – No limits on scope of applications and No limits on scope of applications and � amount of heterogeneous applications amount of heterogeneous applications 12 Dr. Kanda Runapongsa, Khon Kaen University 6

Java Web Services, Software Park Thailand, 2004 Web Services Usage Example Web Services Usage Example � Growing need for a standard lightweight Growing need for a standard lightweight � infrastructure for data exchange in e- infrastructure for data exchange in e -business business applications applications Distributor XML XML Manufacturing Supplier Factory Internet XML XML Logistics 13 Impact of Web Services on Software � Impact of Web Services on Software � “Application Dis Application Dis � Integration” ” “ � Integration 14 Dr. Kanda Runapongsa, Khon Kaen University 7

Java Web Services, Software Park Thailand, 2004 Macro Web Services – Macro Web Services – Virtual Virtual Systems Systems � A web service is accessed programmatically by A web service is accessed programmatically by � applications or other web services applications or other web services Bank Balance Net worth Stock Position Portfolio Biz News News World News 15 Micro Web Services – Micro Web Services – Virtual Apps Virtual Apps � A web service is accessed programmatically by A web service is accessed programmatically by � applications or other web services applications or other web services Spell Check Grammar Dictionary Word Processing C: \... Publishing http://... 16 Dr. Kanda Runapongsa, Khon Kaen University 8

Java Web Services, Software Park Thailand, 2004 Three Laws of Computing Three Laws of Computing � Moore Moore’ ’s Law s Law � � Computing power doubles every 18 months Computing power doubles every 18 months � � Gilder Gilder’ ’s Law s Law � � Network bandwidth capacity doubles every 12 Network bandwidth capacity doubles every 12 � months months � Metcalfe Metcalfe’ ’s Law (Net Effect) s Law (Net Effect) � � Value of network increases exponentially as Value of network increases exponentially as � number of participants increases number of participants increases 17 Impact on Integration Trigger the Impact on Integration Trigger the Network Effect Network Effect � Metcalfe Metcalfe’ ’s Law: Value of network s Law: Value of network � increases exponentially as number of increases exponentially as number of participants increases participants increases Web Services Custom integration 18 Dr. Kanda Runapongsa, Khon Kaen University 9

Java Web Services, Software Park Thailand, 2004 Myths about Web Services Myths about Web Services � Web Services are something Web Services are something � completely new: Not True! completely new: Not True! � You have to write Web Services from You have to write Web Services from � scratch: Not True! scratch: Not True! � J2EE Platform does not support web J2EE Platform does not support web � services: Not True! services: Not True! 19 Myth: Web Services is a New Myth: Web Services is a New Concept Concept � Web services is distributed computing all Web services is distributed computing all � over again – over again – only now it is based on the only now it is based on the web web Concept Distributed Computing Basic Web Services Concept Distributed Computing Basic Web Services (CORBA/ Java) (CORBA/ Java) Interface Description CORBA IDL, Java Interface WSDL Interface Description CORBA IDL, Java Interface WSDL RPC Support RPC Support ORBS, ldl2java compilers, ORBS, ldl2java compilers, SOAP, compilers for WSDL SOAP, compilers for WSDL rmic rmic Service Registry Service Registry CORBA naming service, CORBA naming service, UDDI UDDI JDNI JDNI Messaging support Messaging support CORBA Event/ Notification CORBA Event/ Notification ? ? service, JMS service, JMS Transaction support CORBA Transaction service, ? Transaction support CORBA Transaction service, ? JTS JTS 20 Dr. Kanda Runapongsa, Khon Kaen University 10