 | Level: Intermediate Michel Mitri (mitrimx@jmu.edu), Associate Professor, James Madison University
Nicholas Chase (ibmquestions@nicholaschase.com), Freelance writer, Backstop Media
03 Oct 2006
Updated 08 Mar 2007 This series details the creation of a mashup application that gives control over the data displayed back to the user; to do that, you need to build in intelligence. Now that you know how to represent information in RDF, you can start to create an ontology using the XML-based Web Ontology Language (OWL), which will enable you to automatically choose between services and parts of services.
In this tutorial
The purpose of this tutorial series is to create a mashup application so smart that users can literally add and remove services at will, and the system will know what to do with them. The series progresses as follows: -
Part 1: You learn about the concept of mashups and how they work. You then build a simple version of one and also discover serious performance problems involved in making potentially dozens of Web calls.
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Part 2: You solve some of that problem by using DB2's new pureXML capabilities to build an XML cache, which saves the results of previous requests and also enables you to retrieve specific information.
- Parts 3, 4, and 5: Ultimately, you will need to use ontologies, or vocabularies that define concepts and their relationships, so in Part 3 you started that process by learning about RDF and RDFs, two key ingredients in the Web Ontology Language (OWL), which is discussed here in Part 4. In Part 5, you will take the ontologies created in Part 4 and use them to enable users to change out information sources.
- Part 6: At this point, you have a working application and the framework in place so that the system can use semantic reasoning to understand the services at its disposal. In this part, you give the user control, enabling him or her to pick and choose the data that is used for a custom mashup.
During the course of this tutorial, you will build a sample ontology for a bookstore, which will enable you to look at how to switch out one bookstore for another in Part 5.
Objectives - What ontologies are
- What the Web Ontology Language is
- The different species of OWL
- How to create an ontology
- How to create subclasses
- Different types of OWL properties
- How to add information to the ontology to enable reasoning
- OWL-S and what it means for the classification of Web services
Prerequisites
This tutorial is for readers who want to better understand the development of ontologies, or classifications of concepts, and how they relate to the semantic Web. It is also for readers who want to understand some of the reasoning options made available by the Web Ontology Language (OWL). This tutorial assumes that you are familiar with the concepts behind the Resource Description Framework (RDF), which you can gain by reading Part 3 of this series. You should also have general familiarity with XML, but we will not be going deeply into these concepts.
No programming skills are required to complete this tutorial.
System requirements
You will need JavaScript enabled in your browser. To follow along with the code in this tutorial, you will need to install and test the following software:
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IBM® DB2® 9 (formerly known as "Viper"): This relational database also includes significant XML capabilities, which you'll need for this tutorial. You can download a trial version of DB2 9: DB2 Enterprise 9 or DB2 Express-C 9, a no-charge version of DB2 Express 9 data server.
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Apache Tomcat or other servlet engine: This tutorial assumes that you will build Web applications using servlets, so you'll need a servlet engine such as Apache Tomcat. If you choose to build the application using another environment, just make sure you have the appropriate software on hand. Download apache-tomcat-5.5.17.zip and install into a directory with no spaces in the directory name.
- Java: Apache Tomcat 5.5, with which this tutorial is built, requires Java 1.5 or higher. Download the J2SE SDK.
- To make things easier, you can use an IDE such as Eclipse or IBM Rational™ Web Developer for your development. You can download Eclipse at Eclipse.org, download a trial version of Rational Web Developer, or use your favorite development environment. You won't be doing anything fancy as far as compilation and deployment are concerned.
Duration
2 hours
Formats html, pdf
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