How can I configure simple web cache for Java client application?

Question

My application sends http requests to a webservice, but because the Terms of Service limit it to one query per second it is very important for me not to send more queries than I need. I put the results of some queries into a database that I check before trying the query again but some queries results are not well suited to putting in database so I would like some sort of dumb cache that would intercept my webservice calls and if the call was a duplicate just send the results of the previous call. I would expect to be able to configure the size of the cache and have it automatically remove the oldest entry if it fills up, it would be great if the cache could be configured as a file rather than use heap memory because my application is already quite memory intensive

Answer 1

For a simple caching solution try Google Guava libraries . The CacheBuilder/CacheLoader could be configured to your requirements. Guava provides a simple caching solution that is more sofisticated than java's own HashMap but light weight when compared to Ehcache and others. This cache could be used in a web service request interceptor that helps to decide whether to initiate a web service call.

A good tutorial with an example for Guava cache could be found here