Force used cached/local rather than download "script" each time

Question

in my jsp , i have this
<script language="javascript" src="something.js"></script>
so each time the jsp page is loaded, the browser will gurantee go to the server and download something.js . is there anyway to force something.js to remain in user browser cache as long as possible > 30 days or so... so that the next time user visit the website, this something.js can be skipped and speed up page load time?

Answer 1

I doubt it. Once the user closes his browser, I image the cache is wiped out. Also, it is not likely to keep his browser open for 30 days straight. I don't think this is a good area to look into to speed up your application. Even if you could cache the *.js, I doubt it will speed things up much. In performance tuning, you normally identify the worst bottleneck, fix it, then move on to the next one. Bottlenecks often involve fetching too much data from the database at once (example: fetching all the records from a database table rather than a subset). Also, sending too much information to the display, so much that the user can't possibly use at one viewing. In code, its often creating too many objects.