1. Web Services Course Introduction Week1 Eva Rose, Ph.D.

2. Who am I? ● Became interested in programming in H.S. ● Masters thesis on Java and the Java Virtual Machine. ● Ph.D. thesis on the Java bytecode verifier. ● Studied web services at IBM T.J.Watson research center. ● Teach web services and advanced programming language theory to graduate students and juniors. ● Attached to Center for Collaborative and On- Demand Computing (CCODC).

3. Syllabus ● also available from http://eva.rose.namehttp://eva.rose.name ● contact and course announcements ● course objective, approach, and assessment ● class participation and attendance ● course overview

4. Introduction to Web services. ● What is a web service? ● SOA and distributed information systems ● Web service architecture

5. Go and explore.... ● go to the w3c.org website, or ● go to the oasis.org website.

6. What does web services “solve”? ● Evolved around the problem of application integration in distributed systems. ● Removes the need for tightly coupled components, ● resulting in monolithic, inflexible applications. ● Hides technical details about the service behind the service Interface

7. When does SOA and web services apply? ● part of the solution exists in multiple networks. ● solution components are built and run by different organizations. ● the components which needs to be integrated have heterogenious platforms (OS, application server, programming language). ● the business process could be automated without human interaction. ● dynamic and flexible business environmet.

8. Example of an XML document ● Viewing Listing 2.1: purchase order iinformation in a browser.

9. The XML document prolog ● The processing instruction “?xml” identifies a document as an XML document. ● All XML documents begins with:

10. Comments in XML ● cannot be nested.

11. XML syntax rules ● Elements ● Attributes ● Character data ● organized as a tree. ● one root element ● child, parent, sibling,...

12. XML Element syntax ● Element start and end tags:... ● Empty element: ● Non-empty:... Element content (ie, text, XML)

13. XML Attribute Syntax ● name-value pair ● lives within an element (start) tag. name = “ value”

14. Character data (reserved) ● encoding, whitespace, entities. <>&'“<>&'“ CharacterEscape sequences < > & &apos; "

15. Exercise: Escape characters ● Go to eclipse on your lab machine. ● Use the text editor to enter the XML document on p.43. ● Open the XML document in your browser. What do you see?

16. The CDATA construct ● Allows any sequence of characters. <![ CDATA{... ]]>

17. Exercise: CDATA ● Go to the previous file (corresponding to the XML document on p. 43). Use the CDATA construct instead of all the escape characters.

18. See you next week. Lecture (please read in advance): p.44-91.