Eva Rose, Ph.D.
Who am I?
● Became interested in programming in H.S.
● Masters thesis on Java and the Java Virtual
● Ph.D. thesis on the Java bytecode verifier.
● Studied web services at IBM T.J.Watson
● Teach web services and advanced
programming language theory to graduate
students and juniors.
● Attached to Center for Collaborative and On-
Demand Computing (CCODC).
● also available from http://eva.rose.name
● contact and course announcements
● course objective, approach, and assessment
● class participation and attendance
● course overview
Introduction to Web services.
● What is a web service?
● SOA and distributed information systems
● Web service architecture
Go and explore....
● go to the w3c.org website, or
● go to the oasis.org website.
What does web services
● Evolved around the problem of application
integration in distributed systems.
● Removes the need for tightly coupled
● resulting in monolithic, inflexible applications.
● Hides technical details about the service
behind the service Interface
When does SOA and web
● part of the solution exists in multiple
● solution components are built and run by
● the components which needs to be
integrated have heterogenious platforms
(OS, application server, programming
● the business process could be automated
without human interaction.
● dynamic and flexible business environmet.
Example of an XML document
● Viewing Listing 2.1: purchase order
iinformation in a browser.
The XML document prolog
● The processing instruction “?xml” identifies a
document as an XML document.
● All XML documents begins with:
<?xml version=”1.0” encoding=”UTF-8” ?>
Comments in XML
● cannot be nested.
<--! this will not be processed as XML -->
XML syntax rules
● Elements ● organized as a tree.
● Attributes ● one root element
● Character data ● child, parent, sibling,
XML Element syntax
● Element start and end tags: <po> ... </po>
● Empty element: <po />
<po> Element content
... (ie, text, XML)
XML Attribute Syntax
● name-value pair
● lives within an element (start) tag.
name = “ value”
Character data (reserved)
● encoding, whitespace, entities.
Character Escape sequences
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?
The CDATA construct
● Allows any sequence of characters.
● Go to the previous file (corresponding to the
XML document on p. 43). Use the CDATA
construct instead of all the escape
See you next week.
Lecture (please read in advance): p.44-91.