DOWNLOAD XAMPP WHATS THE USE OF IT?
X->xml
A->Apache
M->MySql
P->Php
P->Perl
So just follow this link to download it:http://en.softonic.com/s/xampp-64-bit
Just press download on First one!!if you are Having 64bit computer!!
Whats the use?
Variety of uses are there so basically first use is if you are  want to run JSP programs then you can use Apache and for database there is MySql in Backend

WHERE TO PUT MY JSP CODE???
->There is docs folder under folder where you have downloded your XAMPP
under bin->there is docs folder in which you can put your  code
under your self name folder .jsp extension(this contain index.html and .jsp file)