Jersey: Default Cache Control to no-cache

Question

While writing a RESTful web service, I am encountering issues if I enable any sort of caching on my client (currently a .NET thick client). By default Jersey is not sending any sort of cache control header, so the client is caching most pages automatically (which seems to be valid behaviour).

I would like to have Jersey by default send a cache control of "no-cache", and then in particular responses override the cache control.

Is there any way to do this with Jersey?

I've found that RESTeasy has the ability to use the @NoCache annotation to specify the setting for the whole class, but I've not found anything similar with Jersey.

Answer 1

This is easy with Jersey by using a ResourceFilterFactory - you can create any custom annotation you attach to your methods to set cache control settings. ResourceFilterFactories get called for each discovered resource method when the application initializes - in your ResourceFilterFactory you can check if the method has your @CacheControlHeader annotation (or whatever you want to call it) - if not, simply return response filter that adds "no-cache" directive to the response, otherwise it should use the settings from the annotation. Here is an example of how to do that:

public class CacheFilterFactory implements ResourceFilterFactory {     private static final List<ResourceFilter> NO_CACHE_FILTER = Collections.<ResourceFilter>singletonList(new CacheResponseFilter("no-cache"));      @Override     public List<ResourceFilter> create(AbstractMethod am) {         CacheControlHeader cch = am.getAnnotation(CacheControlHeader.class);         if (cch == null) {             return NO_CACHE_FILTER;         } else {             return Collections.<ResourceFilter>singletonList(new CacheResponseFilter(cch.value()));         }     }      private static class CacheResponseFilter implements ResourceFilter, ContainerResponseFilter {         private final String headerValue;          CacheResponseFilter(String headerValue) {             this.headerValue = headerValue;         }          @Override         public ContainerRequestFilter getRequestFilter() {             return null;         }          @Override         public ContainerResponseFilter getResponseFilter() {             return this;         }          @Override         public ContainerResponse filter(ContainerRequest request, ContainerResponse response) {             // attache Cache Control header to each response based on the annotation value             response.getHttpHeaders().putSingle(HttpHeaders.CACHE_CONTROL, headerValue);             return response;         }     } } 

The annotation can look like this:

@Retention(RetentionPolicy.RUNTIME) @Target(ElementType.METHOD) public @interface CacheControlHeader {     String value(); } 

The ResourceFilterFactory can be registered in your application by adding the following init param to the definition of Jersey servlet in web.xml:

<init-param>     <param-name>com.sun.jersey.spi.container.ResourceFilters</param-name>     <param-value>package.name.CacheFilterFactory</param-value> </init-param>