Uni Göttingen
Institute for Informatics
Databases and Information Systems

dbis

Practical Training XML
Winter Term 2023/24

Prof. Dr. Wolfgang May

  • Module M.Inf.1802, 4 SWS, 6 ECTS-credits; it is graded (=benotet)

Course Description

The practical training builds upon the lecture Semistructured Data and XML. It introduces XML application programming based on Java and on Web Services.

Prerequisites:

  • Successful participation in the module Semistructured Data and XML or comparable good knowledge in XML, and
  • Successful participation in the "General Programming Lab/Allgemeines Programmierpraktikum" (or an equivalent course on Programming+Java).

The training uses the concepts of the XML world: XML, DTD, XPath, XQuery, XSLT, XLink, XML Schema, SQL/XML, XML APIs for Java (DOM, SAX, StAX, JAXB), and Web Service infrastructure (Apache Tomcat).
Most of the course uses the geographical sample database "Mondial" in its XML version.

  • Date and Time: Mon 14-18
  • Room: IFI 2.101 (North Campus) online via BBB
  • The course takes place in groups of 3-4 persons. There are usually 5 units: XPath/XQuery, XSLT (both based on the material of the lecture), XML and Java I (DOM/SAX/StAX), XML and Java II (JAXB and Digester), and Web Services (with an application project).
  • For every unit, there is an exercise sheet which will be discussed with one of the supervisors, using monday 14-18 slots.
  • Every monday: Optional live online "course meetings" with BigBlueButton. Course materials are provided as recordings, so the meetings consist of short comments to the new topic and questions&answers and hands-on support for the ongoing exercise sheet.
  • Materials for self-studying are provided as PDF slides and as videos (from winter term 2020/21)
  • Please also read the general and technical information about DBIS virtual teaching.

Documentation: use the slides from the SSD/XML lecture (the full slide set can be found here; Sections 1-8 were the material of the lecture, the rest is intended for the practical course) and the W3C documentation linked below. For practical exercises, the XML software is installed in the IFI CIP Pool. Short descriptions of the software to be used can be found here.

Prospective Time Schedule

Part I: Review of basics, concepts and languages around XML that should be known from the XML lecture.

Part II: XML and Java

  • 27.11.: 3. Unit: XML and Java I: DOM, SAX, StAX (and hands-on support for XSLT exercises)
    Slides: XML and Java I
    Short online meeting in StudIP/BBB; video material see below, Questions and Answers, Hands-on-meeting.
    Code fragments from the slides: to download
    Video: see StudIP WS20/21: Meeting "XMLP-2020-11-30-dom-sax-stax"
    • Exercise Sheet 3: DOM/SAX/StAX [ catdata.xml ]
    • The exercise sheet contains 7 exercises:
    • Exercises 1 and 2 are smaller "warmup" exercises for DOM and SAX/StAX, they should be done groupwise such that everybody gets into the new material. The discussion of these exercises will be rather short.
    • Ex. 3 goes a bit deeper into the idea of stream processing of XML and Java threads.
    • Exercises 4-7 handle a "real use case" in different ways. The presentation of these bigger exercises should not just be like "yes, I did it", but to present the solution ideas+strategy, an informative overview of the code and the interesting aspects, and the lessons learnt by doing it.
    • Presentations/Discussion preferably on 11./18.12.2022 (for this, we need probably two appointments).
  • 4.12.: Discussion of Exercise Sheet 2 (XSLT)
  • 11.12.2023: 4. Unit: XML and Java II: JAXB, Digester
    Slides: XML and Java II.
    JAXB uses XML Schema: Slides XML Schema
    Code fragments from the slides: to download (including the readme with the shell commands for JAXB).
    The Digester jar files can be found in /afs/informatik.uni-goettingen.de/user/d/dbisuser/XML-Tools/Digester (CIP Pool) or here.
    Note: the Digester examples on the slides work in the IFI-Pool only when /afs/informatik.uni-goettingen.de/group/dbis/public/oracle/lib/xmlparserv2.jar is not in the classpath (situation in 2019).
    Video see StudIP WS20/21,
    Exercises: Exercise Sheet 4: JAXB, Digester, HTML processing (groupwise discussion 8.1.2024)
  • 11.12.2023 afterwards: Discussion of some exercises from Exercise Sheet 3.
  • 18.12.2023: Discussion of the rest of Exercise Sheet 3.

Part III: Project/Scenario

  • 8.1.2024: 5. Unit: Web-Server-Technology, HTTP, Servlets.
    Video: see StudIP WS20/21,
    Slides: Web Services
    Installation instructions for tomcat
    XQuery Demo Servlet as .war-file
    Servlet Demo Source Code
    DBIS Git with sources for XQuery (and SQL) Web Services
    (note to myself: add all XML-P-participants in gitlab to the group dbis/Teaching/XML-Praktikum-Teilnehmer)
    For using other people's Web Services, you need HTTP internet access to their tomcat/apaches. This is usually not possible "behind" an internet provider (dynamic IP addresses). For this, you can use the institute's shell servers (with ssh forwarding) and install tomcats there (if you are on the same shellX, then bind your individual tomcats to 8080, 8081, 8082 ...):
       * login.stud.informatik.uni.goettingen.de -> shell1.cip.loc  ... shell8.cip.loc
    
  • Exercise Sheet 5: Web Services, Project: University Information Services - EXA, StudIP, FlexNow
  • 8.1.: Discussion of Exercise Sheet 4.
  • 15.1.: Project Meeting
  • 22.1.: Project Meeting, Discussion of the Exercises of Exercise Sheet 5
  • FlexNow Registration: is now opened, until Feb 10th
  • 29.1.: Project Meeting
  • 5.2.: Project Meeting