Cache HTTP Response in Spring MVC Rest service

Question

I have a spring MVC rest service that returns data in XML. I would like to cache this xml response. How can I achieve this? Is it possible to do this using mvc:interceptors?

Answer 1

You could make this work, but I think there are better solutions.

First, if you want to use Spring MVC interceptors, you'll use the postHandle method to store something in your cache and the preHandle to check the cache and possible circumvent processing. The question is, what do you store in the cache. You would need to store the complete response. This means that you would have to easily get the full response from your ModelAndView in postHandle. This may or may not be easy, depending on how you're doing things.

You're most likely better off using a different caching mechanism all together. I recommend caching at the web server level. This is especially true if you're looking to cache in the interceptor level as that is right "next" to the web server and I don't see any benefit in re-inventing the wheel there. Apache has a cache module. So does nginx. Varnish is pretty awesome too.

I should also mention that you should not cache until you've determined that you need to (don't prematurely optimize). This is a waste of your time and effort. Secondly, when you've determined that you do have performance issues that need to be fixed (and caching is the correct solution), you should cache the right data in the right place.

Now, say you've determined that you do have a performance problem and some sort of caching is a good solution. The next thing to determine is what can be cached. If, for every URL, you return the same data, then caching at the web server (Apache, nginx, Varnish, etc.) level will be your best bet.

Often, you will have cases where two clients will hit the same URL and get different data. This is most easily seen on a site like Facebook. I see different data when I'm logged in than my friend sees. In this case, you will not be able to cache at the web server level. You will need to cache inside your application. Usually this means caching at the database level.