Question

I have a jsp file pageshow.jsp and the parameter id,

Is there any way to cache the jsp file in server-side based on the url parameter

Requesting page pageshow.jsp?id=100 get from cache instead of building from server
Requesting page pageshow.jsp?id=200 get from cache instead of building from server

Above two pages should have different cache content since their parameter are different

This may avoid the rebuilding the jsp file in server side and also decrease the server load

Answer 1

I’d take a look at using a CachingHttpFilter similar to what AlexR has proposed, but look at using the HTTP headers to control the caching rather than storing data in a roll-your-own-content-cache.

This article explains nicely how to go about comparing the If-Modified-Since HTTP header when a URL is requested subsequent times. It’s then up to your Filter to send back a HTTP 304 response.

Comparison of dates:

The client asks the server to a specific page: if the client has
already read the page, it sends a request (to server) containing the
last modification date of its cached page (eg “If-Modified-Since:
21/07/2002 13:47:24 GMT”);There also the header If-Unmodified-Since;

The server compares this date given by the client with the last
modified date of requested page:

if the page on the server has the same date, then the server informs
the client that it can use the version’s page in its cache (“HTTP/1.1
304 Not Modified”). The exchange between client and server stops
there;

if the page on the server is newer, then the server informs the client
of the change (“Last-modified: 21/06/2012 08:45:37 p.m. GMT”) and sent
this page to client. The browser stores the date of last change of the
page.

You will also want to look at the ETag HTTP Header.

Unfortunately caching sounds simple but is often difficult to get right. Tuning your database queries is often the best place to start with improving your application performance.