WebServices

<slideshow style="nobleprog" headingmark="⌘" incmark="…" scaled="true" font="Trebuchet MS" >

title

Web Services Basics For Non-programmers

author

Pete George (NobleProg Ltd)

</slideshow>

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 ⌘

Remote Procedure Call (RPC)⌘

RPC Protocols ⌘

Protocols, e.g. DCOM, specify:

• 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 ⌘

Web Services History 1 ⌘

Web Services History 2 ⌘

Web Services History 3 ⌘

Web Services Today ⌘

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 ⌘

Merging Systems ⌘

Why are Web Services Popular? ⌘

• Development benefits

-Interoperability

-Reduced development time

-Reduced maintenance

-Reduced brittleness

Interoperability ⌘

Reduced Development Time ⌘

Reduced Maintenance ⌘

Brittleness ⌘

Reduced Brittleness XML ⌘

Reduced Brittleness JSON ⌘

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! ⌘