Good day, I am using CacheFilter to filter a certain path to my server (which outputs an image stream to the response stream). And I've configured it in my web.xml as follows: <filter> <filter-name>imagesCache</filter-name> <filter-class>com.samaxes.cachefilter.presentation.CacheFilter</filter-class> <init-param> <param-name>privacy</param-name> <param-value>public</param-value> </init-param> <init-param> <param-name>expirationTime</param-name> <param-value>2592000</param-value> </init-param> </filter> ... <filter-mapping> <filter-name>imagesCache</filter-name> <url-pattern>/my/path/*</url-pattern> </filter-mapping> Using my firefox, if I access my url via the address bar, it hits the server the first time but uses the cache during succeeding calls. However, if the url is inside my page ( i.e. <img src="..."/> ), it seems to hit the server all the time. [EDIT] After a few more testing, accessing my image via the address bar does not work all the time. But caching does seem to work more often with it than . As to whether it really, I am not sure. Additional Info: my path is something like /my/path?then=some&query=strings. Notice that it doesn't have an extension (i.e. gif, png, jpeg ) but it's mimetype is set properly ( image/gif, image/png, image/jpeg ). I am not sure if the lack of extension or the presence of the query strings have any impact. (Also, another note. though my url have query strings, I am using the same uri + query string over and over again with my tests). Any ideas why? Thanks