RSS News Aggregator

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RSS News Aggregator

• by Cheng Guo

Advised by Gary Ridsdale Chris Watkiss
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What is RSS?

• RSS stands for Really Simple Syndication
• A XML-based file format for syndicating web
  content, such as news and blogs.
• RSS is not limited to news and blogs, it can be
  used for anything that can be broken down into
  discrete items.

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What is RSS feeds and News Aggregator?

• RSS feed is an XML file that contains information
  written in the RSS format.
• A News aggregator is either a web-based or
  desktop application that helps users to manage
  and syndicate RSS feeds.

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Versions of RSS
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A typical RSS 2.0 feed

• lt?xml version"1.0" ?gt
• - ltrss version"2.0"gt
• - ltchannelgt
•   lttitlegtLiftoff Newslt/titlegt
•   ltlinkgthttp//liftoff.msfc.nasa.gov/lt/linkgt
•   ltdescriptiongtLiftoff to Space
  Exploration.lt/descriptiongt
•   ltlanguagegten-uslt/languagegt
•   ltpubDategtTue, 10 Jun 2003 040000
  GMTlt/pubDategt
•   ltlastBuildDategtTue, 10 Jun 2003 094101
  GMTlt/lastBuildDategt
•   ltdocsgthttp//blogs.law.harvard.edu/tech/rsslt/doc
  sgt
•   ltgeneratorgtWeblog Editor 2.0lt/generatorgt
•   ltmanagingEditorgteditor_at_example.comlt/managingEdit
  orgt
•   ltwebMastergtwebmaster_at_example.comlt/webMastergt
• - ltitemgt
•   lttitlegtStar Citylt/titlegt
•   ltlinkgthttp//liftoff.msfc.nasa.gov/news/2003/new
  s-starcity.asplt/linkgt
•   ltdescriptiongtHow do Americans get ready to work
  with Russians aboard the International Space
  Station? They take a crash course in culture,
  language and protocol at Russia's lta
  href"http//howe.iki.rssi.ru/GCTC/gctc_e.htm"gtSta
  r Citylt/agt.lt/descriptiongt
•   ltpubDategtTue, 03 Jun 2003 093921
  GMTlt/pubDategt
•   ltguidgthttp//liftoff.msfc.nasa.gov/2003/06/03.ht
  mlitem573lt/guidgt

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System Design
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System Design User Interface
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System Design - Mediator
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System Design Multi-Threading

• Depending on the users internet connection, the
  time needed for updating each RSS feed varies
  significantly.
• We need to allow users to interact with the
  application while the application is updating RSS
  feeds.
• Solution use a different thread to handle RSS
  updating and another thread to respond to any
  changes in the GUI.

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System Design RSS Parsing

• Each tag is an object.
• Identifying tag at runtime.

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System Design RSS Parsing
if (current_tag.equals("title"))
else if(current_tag.equals("lin
k") . else if .
Class c Class.forName(tag_name)
Class parameter new ClassString.class
Method m c.getMethod(METHOD_NAME,parameter)
Object o c.newInstance() Object
argument new Object fixed m.invoke(o,argume
nt)
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System Design RSS Parsing

• Advantages of representing tags as objects
• It is easy to support further RSS format changes
  if new tags are needed.
• Reduce the complexity of code.
• Parse only necessary tags
• Improve performance

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System Demonstration

• Any questions?