RESTEasy provides the @Cache and @NoCache annotations, following the JAX-RS specifications, with the @GET annotation for controlling the cache. These annotations can be applied at class and method levels.

The @NoCache annotation is used to specify when caching is not required; hence, the server needs to respond back with a fresh response for every request.

The @Cache annotation is used when the caching of a response is required. Given ahead is a brief list of attributes used to control the caching behavior. Take some time to refer to the previous chapter, which talks in detail about each of these attributes.

• maxAge: This indicates the maximum time the response message will remain in the cache.
• sMaxAge: This is the same as maxAge, but it applies for a proxy cache. 
• noStore: This is used to avoid caching sensitive information set to true.
• mustRevalidate: If this is true, it revalidates the cache content and serves the fresh response.
• proxyRevalidate: This is the same as mustRevalidate, but it applies for a proxy cache. 
• isPrivate: If this is true, the response messages will be cached for a single user only and will not be shared. If false, it means that the response messages can be cached by any cache. 

Given ahead is the application of cache-control annotations for caching the response of the findDepartment function of DepartmentService:

//The response of findDepartment method will be cached for the specified maxAge //duration and user will get the response from cache for same department id //request until the cache expires.

 @GET
 @Path("{id}")
 @Produces(MediaType.APPLICATION_JSON)
 @Cache(maxAge=2000,mustRevalidate = false,noStore = true, proxyRevalidate = false, sMaxAge = 2000)
 public Departments findDepartment(@PathParam("id") Short id) {
 return entityManager.find(Departments.class, id);
 }

In the preceding code snippet, when the client invokes the findDepartment function, the server will respond back with the response from the cache if it exists; otherwise, it will execute the function and return the response. In the latter case, the response will be cached as per the caching definition and will be used to serve future requests.