Resteasy is a popular Java framework for building RESTful web services. One of its features is the ability to cache HTTP responses using the @Cache and @NoCache annotations.
Caching REST Response
To use the @Cache annotation, you need to add it to a method that returns an HTTP response. The annotation takes a few parameters that control the caching behavior. For example, you can specify the maximum age of the cached response, or the number of seconds it should be cached for. You can also specify a list of headers that should be included in the cached response.
Here is an example of how to use the @Cache annotation:
@GET @Path("/cache") @Cache(maxAge = 3600, sMaxAge = 1800, mustRevalidate = true, proxyRevalidate = true) public Response getCustomerCache() { Customer c = new Customer("John Doe"); return Response.ok(c).build(); }
The above example will cache the response for one hour (3600 seconds) for the client, and 30 minutes (1800 seconds) for any intermediate proxy servers. It also requires revalidation from the client and proxy after the cache expires.
Here is the Header of the Response when we call the endpoint:
Disabling Cache
The @NoCache annotation can be used to prevent caching of a specific resource. You simply need to add it to the method that returns the response.
Here is an example of how to use the @NoCache annotation:
@GET @Path("/nocache") @NoCache public Response getCustomerNoCache() { Customer c = new Customer("John Doe"); return Response.ok(c).build(); }
The above example will prevent caching of the response for this specific resource.
Here is the Response Header when we invoke the endpoint:
It is important to note that, caching can only be useful when it is used correctly, and it is not a substitute for good server-side performance. The use of caching should be considered on a case-by-case basis and be part of a overall performance optimization strategy.
Conclusion
In summary, Resteasy’s @Cache and @NoCache annotations provide a simple way to enable caching of HTTP responses. The @Cache annotation can be used to specify caching parameters, while the @NoCache annotation can be used to prevent caching of a specific resource. It is important to use them correctly in order to improve the overall performance of your RESTful web service.