CS 502 Architecture of Web Information Systems and Digital Libraries Spring 2002 Assignments

Assignment 0 (January 29, 2002)
Assignment 1 (February 14, 2002)
Assignment 2 (March 7, 2002)
Assignment 3 (April 18, 2002)
Assignment 4 (May 15, 2002)

Philosophy

There will be several programming assignments throughout the semester.  The assignments are designed to give students some practical experience in dealing with the technologies that make the Web and digital libraries work.  In general, the assignments will require students to understand relevant protocol or specifications documents and write a small to moderate amount of java code that demonstrates an understanding of those specifications.

These assignments are not a test of your programming skills.  Rather they meant to encourage you to read protocol specifications and APIs.  In the real world this is not done in isolation.  Thus,  students are expected to work in groups on these assignments.  At the beginning of the semester the class will break up into groups of three that will remain together for the remainder of the semester.  Members of the group are expected to share information, jointly understand protocol documents and APIs, and write the final code product.  Every member of the group will receive the same grade for the assignment and it is the responsibility of the group to ensure that the work is apportioned fairly.

Prerequisites

The assignments assume that students can program in Java and understand how to download and use class libraries.  No java or programming tutorials will be offered.

Grading

This is not a programming course.  Imaginative algorithms or data structures will not be required or play a role in grading.  Instead, grading will be based on completion of the assigned task and demonstrated understanding of the concepts and protocols underlying the assignment.  Nevertheless, assignments should demonstrate good programming practices and documentation commensurate with the 500 level of this course. 

Programming Environment

Metrowerks CodeWarrior and Borland JBuilder are the preferred environments for developing and testing programs. One of the two is required for submitting assignments.  CodeWarrior is in all the CIT and CSUG labs.  A personal version of JBuilder is available for free at http://www.borland.com/jbuilder/personal/. The assignments have been tested in both environments.

Submitting Assignments

All assignments are due by the beginning of the lecture on the due date.  NO LATE ASSIGNMENTS WILL BE ACCEPTED.

To identify your assignments and  make grading easier, assignments MUST conform to the following guidelines.  :

• Each group should identify a group leader when they form.  That persons name will serve as the "FirstLast" in the remainder of these instructions.
• The CodeWarrior or JBuilder project must be named as FirstLastAssignment# (e.g., CarlLagozeAssignment1)
• The first executable line of the program should be System.out.println("FirstLastAssignment#")
• The assignment must be submitted as an email to both lagoze@cs.cornell.edu and sk332@cs.cornell.edu with:
  • one attachment consisting of a zip file containing the project directory tree.  The name of the zip file should be as "FirstLastAssignment#.zip". An example of such a zip file is here.
  • the subject line of the email should be "CS502 FirstLastAssignment#"

Submissions that fail to conform to these guidelines will be rejected.

Work Groups

The assignment groups are:

• Newman, Gupta, Kwong
• Goines, Shay
• Yan, Tang
• Daniel, Dickinson, Anthony
• Ho, Wang, Gu
• Borbat, Yuen
• Kuhn, Ankrah
• Gan, Raad
• Miniman, Yueh
• Faaborg, Kim, Perm-Ajchariyawong

Assignment 0 - Due 1/29/2002

The purpose of this assignment is to ensure that you are familiar with the assignment submission process.  

Resources for assignment 0

• Sample submission zip file - here.

Directions for assignment 0

Write a java program that prints out your name and the assignment number in the format "FirstLastAssignment#".

Assignment 1 - Due 2/14/2002

The purpose of this assignment is to develop some experience with the HTTP protocol that serves as the basis of the World Wide Web.  Most of us only experience the Web only through a browser, such as Internet Explorer, but there is interesting and relatively simple technology under the covers.

Resources for assignment 1

• HTTP Protocol Specification - This is a long specification with only small portions that are relevant to this assignment.  One of the skills in working with specifications is not reading them linearly but navigating to the information you need.
• HTTPClient library - a class library for constructing HTTP requests and processing the responses
  • HTTPClient.jar - the class library
  • javaDoc for HTTPClient
• jTidy library - a class library for parsing and manipulating HTML documents
  • tidy.jar - the class library
  • javaDoc for jTidy

Directions for assignment 1

Write a java program that:

• takes as input parameters a URL and a MIME type
• issues an HTTP request to the input URL specifying the input type as the acceptable return type
• prints out the response headers returned by the HTTP server
• Prints out the status code and error message if any
• For HTML documents parses the returned document using the Tidy parser and output the resulting:
  • error and warning messages
  • resulting XHTML document if the parse is successful.

Assignment 2 - Due 3/7/2002

The purpose of this assignment is to develop experience parsing and manipulating XML documents using DOM, SAX, and XSLT.  XML is an fundamental part of the toolset that moves the Web from a network of documents to a globally distributed database.

Resources for assignment 2

• Apache crimson 1.1 - A Java XML parser that supports the JAXP 1.1 API.
• Instant saxon - XSL processor for Windows.

Directions for assignment 2

This assignment has three parts as stated below.  Please submit the assignment in one zip file. The zip should consist of three directories: part1, part2, part3, corresponding to the parts described below.  Parts 1 and 2 will be JBuilder project directories and part 3 will be a single xsl file.

Part 1: DOM processing

Write a java program that:

• takes as input parameter a URL (you can use http://www.w3.org/ as a good test case)
• reads the XML file (XHTML) file from the HTTP server
• parses the file using the DOM API in crimson
• analyzes the resulting DOM tree, locating the <meta> and <a> tags and produces a DOM tree that corresponds to the structure in the file dom.xml (an entry in the document for each corresponding tag)
• Write the output DOM tree to the console.

Part 2: SAX Processing

Write a java program that:

• takes as input parameter a URL (you can use http://www.w3.org/ as a good test case)
• reads the XML file (XHTML) file from the HTTP server
• parses the file using the SAX API in crimson
• locates each meta tag and writes a simple console output formatted as in sax.txt (an entry in the document for each meta tag)

Part 3: XSL Processing

Write an XSL document that processes an XML document using saxon and produces an HTML document formatted as meta_report.html.  Notes:

• You should use http://www.w3.org/ as your test case.
• HINT!: pay attention to namespace issues in the source document, and corresponding effect on the XSLT match rules.
• The url in the output report should not be hard-coded but provided by a parameter to saxon.

 Assignment 3 - Due 4/18/2002

The purpose of this assignment is to give you some experience with the most developed of RDF tools; the jena toolkit developed by HP labs in Bristol UK.  RDF is the one of the basic building blocks of the semantic web and provides the primitives for ontology development and processing.

Resources for assignment 3

• jena semantic web toolkit - a java API for manipulating RDF models.
• ABC.rdfs - RDF schema for the ABC ontology.
• dces.rdfs - RDF schema for simple Dublin Core.

Directions for assignment 3

This assignment has three parts.  Please submit the assignment in one zip file. The zip should consist of two directories: part1 and part3, corresponding to the parts described below.  The part1 directory should contain one file, an RDF schema.  The part3 directory should contain a jbuilder project. Note that part 2 of the assignment has no deliverable.

Part 1: RDF schema extension

The abc schema at ABC.rdfs provides basic resource classes and property types that can then be extended for specific community uses.  You will write an RDF schema - pubABC.rdfs that derives from basic ABC concepts for use in the publishing community. 

This schema defines the following classes:

• "Author" - a refinement of  "Agent"
• "Illustrator" - a refinement "Agent"
• "Publisher - a refinement of "Agent"
• "Publication" - a refinement of "Event"
• "HardCover" - a refinement of "Manifestation"
• "SoftCover" - a refinement of "Manifestation"

This schema defines the following properties:

• "hasAuthor" - a refinement of "hasParticipant"
• "hasIllustrator" - a refinement of "hasParticipant"
• "hasPublisher" - a refinement of "hasParticipant"

Note the following:

• While your rdf schema will be in an independent file from the ABC rdf schema, there is no facility (like xsi:schemalocation) for specifying the URL of another schema.
• Use the namespace of ABC, http://metadata.net/harmony#, to establish the association to ABC properties and classes.
• Create a new namespace URI, http://BooksAreUs.com/pubABC#, for the entities defined in your new schema.
• You may want to use the RDF schema validator and visualizer to test your new schema -
  –http://www.dfki.uni-kl.de/frodo/RDFSViz/.

Part 2: RDF Modeling

In this part of the assignment you will build an RDF model that uses entities from three namespaces:

1. http://metadata.net/harmony# - the ABC ontology
2. http://purl.org/dc/terms# - the Dublin Core properties
3. http://BooksAreUs.com/pubABC# - the extension to the ABC properties that you developed in Part 1 of this assignment.

You should develop an RDF model that describes the following:

A publishing event took place on January 1, 1999.  The event involved an author agent named "Mary Doe" and a publishing agent named "HB publishers".  The event leads to a situation in the context of which a hard cover book called "APIs are Fun - First Release" exists.  A follow on publishing event took place on January 1, 2000.  This event involved an illustrator agent named "John Smith" and a publishing agent named "SB publishers". The event leads to a situation in the context of which a soft cover book called "APIs are Fun - Illustrated" exists.  The soft cover and hard cover books are both realizations of a work called "APIs are Fun".

Please note the following in completing the above:

• You do not need to turn in anything specific to this part of the assignment.  You will be using this modeling exercise as input to Part 3 of this assignment and, thus, can draft this model up using hand-drawn diagrams.
• Use Dublin Core properties in the model to express dates, agent names, and resource titles. (You may use the dc 'title' property for agent names and resource titles).
• The examples in the ABC Ontology paper should provide ample hints on how to create the model.

Part 3: RDF Model Programming

The jena toolkit provides an API for building and manipulating RDF models.  Use jena to write a program that does the following based on the RDF model you developed in part 2:

1. Build a copy of the model in memory.
2. Prints out the values of all dublin core 'title' properties (no special formatting required).
3. Prints out the dates of all the publishing events (no special formatting required).

Before working on this programming task you will find it extremely useful to work through the tutorials in the jena release (you will find them in the tutorial directory).

 Assignment 4 - Due 5/15/2002

The purpose of this assignment is provide the opportunity to examine the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH).  This protocol is increasing popular as a low-barrier interoperability mechanism.

Special Rules for Assignment 4

Due Date and Time

This assignment MUST be submitted via email by 5pm on May 15.  Final grades are due soon after that.

Individual Effort

Unlike previous assignments, assignment 4 should be worked on individually and you will receive an individual grade for it.  You may freely borrow code from your previous assignments, much of which will be applicable for this assignment.

Resources for Assignment 4

• Open Archives Initiative Protocol for Metadata Harvesting - The specification of the protocol that you will use for this assignment.
• Open Archives Initiatives Data Provider Registry - An up-to-date list of repositories that support OAI-PMH, represented as an XML document.

Directions for Assignment 4

Write a Java program that does the following:

1. Read the OAI data provider registry at http://www.openarchives.org/Register/ListFriends.pl .
2. List the BASE-URL of repositories who support a metadata format in addition to the required oai_dc format.
3. For each repository that supports an additional format indicate whether any records have been created in that format since April 1, 2002. You need to only indicate whether "records are available" for one of the additional formats.  For example, if a repository supports oai_dc, marc, and rfc1807 formats, you can pick one (marc) and check if any records are available for that format since April 1, 2002.  Note that this means that you don't have to harvest all the records available for that format and count all of them.  Therefore you can ignore issues related to resumptionTokens - i.e., you can abort after receiving a first "incomplete list".

Hints and Notes:

1. Repeating what was stated above, you may reuse code from earlier assignments including HTTP request and response handling and XML parsing. 
2. The bulk of the work in this assignment is understanding the OAI-PMH protocol document. You are advised to spend time up front understanding the relevant protocol issues and formulating any questions you might have in this area.
3. Output formatting should be as simple as possible; e.g., simple text lists.  No credit will be given for pretty XML formatting.
4. Please submit your work as a single JBuilder or CodeWarrior Project.