How to use CXF, JAX-RS and HTTP Caching

Question

The CXF documentation mentions caching as Advanced HTTP:

CXF JAXRS provides support for a number of advanced HTTP features by handling If-Match, If-Modifi

Answer 1

CXF didn't implements dynamic filtering as explained here : http://www.jalg.net/2012/09/declarative-cache-control-with-jax-rs-2-0

And if you use to return directly your own objects and not CXF Response, it's hard to add a cache control header.

I find an elegant way by using a custom annotation and creating a CXF Interceptor that read this annotation and add the header.

So first, create a CacheControl annotation

@Target(ElementType.METHOD )
@Retention(RetentionPolicy.RUNTIME)
public @interface CacheControl {
    String value() default "no-cache";
}

Then, add this annotation to your CXF operation method (interface or implementation it works on both if you use an interface)

@CacheControl("max-age=600")
public Person getPerson(String name) {
    return personService.getPerson(name);
}

Then create a CacheControl interceptor that will handle the annotation and add the header to your response.

public class CacheInterceptor extends AbstractOutDatabindingInterceptor{
    public CacheInterceptor() {
        super(Phase.MARSHAL);
    }

    @Override
    public void handleMessage(Message outMessage) throws Fault {
        //search for a CacheControl annotation on the operation
        OperationResourceInfo resourceInfo = outMessage.getExchange().get(OperationResourceInfo.class);
        CacheControl cacheControl = null;
        for (Annotation annot : resourceInfo.getOutAnnotations()) {
            if(annot instanceof CacheControl) {
                cacheControl = (CacheControl) annot;
                break;
            }
        }

        //fast path for no cache control
        if(cacheControl == null) {
            return;
        }

        //search for existing headers or create new ones
        Map> headers = (Map>) outMessage.get(Message.PROTOCOL_HEADERS);
        if (headers == null) {
            headers = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
            outMessage.put(Message.PROTOCOL_HEADERS, headers);
        }

        //add Cache-Control header
        headers.put("Cache-Control", Collections.singletonList(cacheControl.value()));
    }
}

Finally configure CXF to use your interceptor, you can find all the needed information here : http://cxf.apache.org/docs/interceptors.html

Hope it will help.

Loïc