====== Class ShortestPathServer ======
Collaborate with ZhangZhi
====== Description ======
a python server responses every URL request which contains 'shortestpath'. It returns a Json file shows the shortest path from source to target in a weighted graph G.
====== Parameter ======
URL: [[http://clans.cse.cuhk.edu.hk/clansV0.002/peopleServlet?type=shortestpath&pid1=1&pid2=2]]

====== Return ======
Json file:

{{:projs:clans:docs:egp.jpg?600|}}
{{:projs:clans:docs:egc.jpg?600|}}

====== Detail Information ======
  - related modules:HTTPServer, BaseHTTPRequestHander, ThreadingMixIn, urlParse
  - MySQLdb:[[https://pypi.python.org/pypi/MySQL-python]]
  - networkx:[[https://pypi.python.org/pypi/networkx/]]
====== Function======
  - [[projs:clans:docs:sps:threadhttpserver.initdataset()]]: Create the social network and initial data set.
  - [[projs:clans:docs:sps:threadhttpserver.getdata()]]: Get dataSet.
  - [[projs:clans:docs:sps:threadhttpserver.getcompanydataset()]]: Get company information.
  - [[projs:clans:docs:sps:handler.do_get()]]
  - [[projs:clans:docs:sps:handler.calp(source,target)]]: Return the shortest from source to target in a weighted graph G.
  - [[projs:clans:docs:sps:handler.calc(source,target)]]: Return the shortest path from source company to target company based on a weighted people social network.
  - [[projs:clans:docs:sps:handler.writejson(path)]]: Return a json file shown on the website about shortest path from person to person.
  - [[projs:clans:docs:sps:handler.writejson(cid1,cid2,pathlist)]]: Returns a json file shown on the website. It is list of shortest path from source company to target company.

====== Implementation ======
  - Main idea:
  -   - call initDataset() as long as the server running
  -   - after data is ready, call do_GET() function when receives an URL request.
  -   - In do_GET() function, the main idea is: extract source pid and target pid, then call Handler.calP(source,target) to get path list of pid, then call Handler.writejson(path) to generate json file. BaseHTTPRequestHandler.wfile.write(json file) to show result on browser.
  - Add flow chat here