WebServices

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title
Web Services Basics For Non-programmers
author
Pete George (NobleProg Ltd)

Day One Schedule ⌘

  1. Introductions
  2. Service-Oriented Architecture
  3. Web Services Overview
  4. XML
  5. SOAP

Web Services Overview ⌘

Learning Objectives

  • To understand what a Web service is
  • To be aware of the development of Web services
  • To understand the reasons for the popularity of Web services
  • To be aware of the existence of Web service standards

Web Services Definition ⌘

“a software system designed to support interoperable machine-to-machine interaction over a network.” (W3C)

“a means to connect services together.” (Barry, 2013)

Web Service Architecture ⌘

SOA 3.png

Remote Procedure Call (RPC)⌘

Web Services 1.png

RPC Protocols ⌘

Protocols, e.g. DCOM, specify: WebServices-2.png

  • What address of target computer looks like
  • How data should be packaged
  • How response is retrieved
  • How to initiate call
  • How to handle errors

Web Services History ⌘

WebServices 2.png

Web Services History 1 ⌘

WebServices 4.png

Web Services History 2 ⌘

WebServices 6.png

Web Services History 3 ⌘

WebServices 7.png

Web Services Today ⌘

WebServices 8.png

Which Type of Web Service? ⌘

  • Best for your development environment
  • Used most by services you will use
  • Used most by external services you will use
  • All of the above

Why are Web Services Popular? ⌘

  • Business benefits
  • Development benefits
  • Snowball effect

Why are Web Services Popular? ⌘

  • Business benefits

-Easier exchange of data

-Industry-wide standards

-More external services available to all

-Efficient merging of systems (e.g. in acquisitions)

Easier Data Exchange ⌘

  • Data elements are sent in addition to value
  • XML:

-<element>value</element>

-E.g. <city>Liverpool</city>

  • JSON

-“element” : “value”

-E.g. “city”:”Liverpool”

What About Mismatches? ⌘

  • Application 1:

-<city>Liverpool</city>

-<town>Cheltenham</town>

  • Application 2:

-<city>Liverpool</city>

-<city>Cheltenham</city>

Agreed Data Exchange Standards ⌘

  • Minimize development costs
  • Minimize processing errors

Semantic Vocabularies ⌘

  • Also known as XML Vocabularies
  • NB: both XML and JSON can use the same vocabularies/elements

-<city>Liverpool</city>

-“city”: “Liverpool”

Industry-Wide Standards ⌘

  • Web services created opportunity to establish industry-wide standardized vocabularies
  • Two types:

-Common Semantic Vocabularies

-Specific Semantic Vocabularies

Common Semantic Vocabularies ⌘

  • EXAMPLES
  • Mail.XML

-XML specification for communication.

  • eXtensible Customer Relationships Language

-XML standard specification to represent customer relationships in a standard way.

  • Open Office XML

-OpenDocument Format (ODF). Open XML-based document file format for office applications.

Specific Semantic Vocabularies ⌘

  • EXAMPLES
  • Flexible Image Transport System Markup Language (FITSML)

-Astronomy XML specification

  • HR-XML

-Human Resources XML specification

  • DocBook

-XML vocabulary for Publishing industry

More External Services Available ⌘

WebServices 9.png

Merging Systems ⌘

WebServices 10.png

Why are Web Services Popular? ⌘

  • Development benefits

-Interoperability

-Reduced development time

-Reduced maintenance

-Reduced brittleness

Interoperability ⌘

WebServices 11.png

Reduced Development Time ⌘

WebServices 12.png

Reduced Maintenance ⌘

WebServices 13.png

Brittleness ⌘

WebServices 14.png

Reduced Brittleness XML ⌘

WebServices 15.png

Reduced Brittleness JSON ⌘

WebServices 16.png

Why are Web Services Popular? ⌘

  • Snowball effect

-Popularity of Web services forced vendors to include in their products

  • More Web services in products increases popularity

-Popularity of Web services ….

-Popularity of Web services create demand for training and tools

  • More training and tools increases popularity of Web services

-Popularity of Web services…

“WS-” Specifications ⌘

  • No single defined set or governing body for Web service specifications
  • “WS-” = shorthand for Web service specifications

-WS-Security, WS-Discovery et al

-SOAP

-XML

-etc

Quiz – No Prizes! No Pressure! ⌘

WebServices 02.png