anchor.diff:  	}
   ----
   
  -
   Doing this will not only include `'ETag'` and `'Cache-Control'` headers in the response, it will **also convert the
  -response to a `HTTP 304 Not Modified` response with an empty body** if the conditional headers sent by the client
  +response to an `HTTP 304 Not Modified` response with an empty body** if the conditional headers sent by the client
   match the caching information set by the Controller.
  -
   
   An `@RequestMapping` method may also wish to support the same behavior.
   This can be achieved as follows:
  
positive.code: === Cache-Control HTTP header
  
  Spring Web MVC supports many use cases and ways to configure "Cache-Control" headers for
  an application. While the https://tools.ietf.org/html/rfc7234#section-5.2.2[RFC 7234 Section 5.2.2]
  completely describes that header and its possible directives, there are several ways to
  address the most common cases.
  
  Spring Web MVC is using a configuration convention in several of its APIs:
  `setCachePeriod(int seconds)`:
  
  * A `-1` value won't generate a `'Cache-Control'` response header
  * A `0` value will prevent caching using the `'Cache-Control: no-store'` directive
  * A `n > 0` value will cache the given response for `n` seconds using the
  `'Cache-Control: max-age=n'` directive
  
  The {javadoc-baseurl}/org/springframework/http/CacheControl.html[`CacheControl`] builder
  class simply describes the available "Cache-Control" directives and makes it easier to
  build your own HTTP caching strategy. Once built, a `CacheControl` instance can be then
  taken as an argument in several Spring Web MVC APIs.
  
  
  [source,java,indent=0]
  
negative.code: Static resources should be served with appropriate `'Cache-Control'` and conditional
  headers for optimal performance.
  <<mvc-config-static-resources,Configuring a `ResourceHttpRequestHandler`>> for serving
  static resources not only natively writes `'Last-Modified'` headers by reading a file's
  metadata, but also `'Cache-Control'` headers if properly configured.
  
  You can set the `cachePeriod` attribute on a `ResourceHttpRequestHandler` or use
  a `CacheControl` instance, which supports more specific directives:
  