I have a file called Main.jsp, located at the absolute url path of \"http://Mywebpage.com/Open/This/Folder/Main.jsp\".
Inside Main.jsp, there is a jsp include:
The is relative to the current request URL (as you see in browser address bar), not to the server side location of the JSP file. It's namely the webbrowser who needs to load the script, not the webserver.
So, if the current request URL is
http://Mywebpage.com/Open/This/Folder/Main.jsp
and the JS file is actually located in
http://Mywebpage.com/HL.js
then you need to reference it as
The leading slash will make it relative to the domain root.
However, if your webapp is not deployed on the domain root per se, but on a context path, such as /Open
in your (oversimplified) example, and your JS file is actually located in
http://Mywebpage.com/Open/HL.js
then you need to prepend the URL with HttpServletRequest#getContextPath().
This will end up as (rightclick page in browser, do View Source to see it)
Update: as per your update, please note that this does not apply on TLD files since they are been resolved on the server side. Normally, you should drop TLD files in /WEB-INF
folder and reference it by uri="/WEB-INF/filename.tld"
.