[2013/1/6 - 2013/1/11] - error handled in json response

[enoy]

override the error resolver to handle the exception in json response.

[enoy]

1/6:
write a HandlerExceptionResolver sample to handle exception & respond json (using PrintWriter).

TODO:
Implement JSON & XML ExceptionResolver.
read spring code to check how to implements ModelAndView
1/7 1. convert object to json & xml
1/7 2. implement view for json & xml
1/8 3. write JSON ExceptionResolver according to SimpleMappingExceptionResolver (how to read prop key)
1/9-10 4. write XMLExceptionResolver according to SimpleMappingExceptionResolver
1/11 5. Integrated HTML, JSON & XML ExceptionResolver

[yanxuehe]

apply my changes to upstream. read it and understand it.
finish the upload file func

[enoy]

fail to push to upstream(master rejected - non-fast-foarward)...
sent code to ur QQ

[enoy]

Format code and change try...catch to throws.