modified some problems:
catch some exceptions
write some comments
version 1.5
modified some problems
GUI v 1.0
no scroll
some problems about bar
change the list to map,
use string buffer,
add the thread.

****************
still have some problems about the thread
Merge branch 'master' of https://github.com/Cynthia1991/assignment2-v2
change the list to map,
using string buffer
add thread
improve the gui
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still have some problem with thread!