+ Webcrawler
???
??? -- study open source code
??? ?? ?? purpose: analyze code structure and basic componences
??? ?? ?? focus on: Nutch (http://lucene.apache.org/nutch/)
??? ??? ??? ??? ??? & HTMLParser (http://htmlparser.sourceforge.net/)
??? ?? ?? ?? ?? ?? ? & GData(http://code.google.com/apis/gdata/overview.html)

??? -- understand PageRank idea
??? ?? relative articles:
??? ?? http://en.wikipedia.org/wiki/PageRank
??? ?? http://www.thesitewizard.com/archive/google.shtml
?????? paper : "PageRank Uncoverd" by Chris Ridings and Mike Shishigin
?????? http://www.rankforsales.com/n-aa/095-seo-may-31-03.html (about Chris Ridings & SEO)
??? ?? http://en.wikipedia.org/wiki/Web_crawler (basic idea about crawler)
??? ??
??? -- familar with RSS & Atom protocol

??? -- sample coding:
??? ?? Interface: Scheduler for fetching web links
??? ?? Interface: Web page paser/Analyzer --> to deal with XML-based websites(Weblogs or news sites, RSS & Atom) --> Paser classes based on SAX parser
??? ?? Interface: Retractor/Fetcher --> to get links from page
??? ?? Interface: Collector --> check URL whether duplicated and save in URL database with certian data structure
??? ?? Interface: InformationProcesser --> PageRank should be one important factor --> (under thinking)
??? ?? Interface: Policies(Filter) --> will be served for Collector and InformationProcessor --> (under thinking)

+ Indexer/Searcher (almost done base on Lucene)