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javarestjax-rsresteasy

How to get the response header in a RestEasy client?


i´m implementing a Restful service using Jax-RS 2.0 (Resteasy 3.0.7.Final) and share the interface between client and service.

The return value is void because ClientResponse is deprecated since RestEasy introduced JAX-RS 2.0 in version 3+.

To return the location of the new created object i inject the response, using the @Context annotation, and add the Content-Location header.

For example:

Shared Interface:

   @Path("/")
   @Consumes("application/xml")
   @Produces("application/xml")
   interface Resource {

        @Path("createSomething")
        void createSomething(AnyObject object);

        ...
   }

Implementation class (The Service):

    class ResourceImpl {

         ...
         @Context org.jboss.resteasy.spi.HttpResponse response;
         ...

         @Override
         void createSomething(AnyObject object) throws AnyException {

             String id = service.create(object);

             response.getOutputHeaders().putSingle("Content-Location",
                  "/createSomething/" + id);

             response.setStatus(Response.Status.CREATED.getStatusCode());
         }

    }

The client (build with the Resteasy Proxy Framework):

     ...
     ResteasyClient client = new ResteasyClientBuilder().build();
     ResteasyWebTarget target = client.target(baseUrl);

     Resource resource = (Resource) target.proxy(Resource.class);   

     resource.createSomething(anyObject);
     ...

How can i retrieve Header information (and others, like Atom Links) which has been injected by the service?

Is it reasonable to use client side Filters and Interceptors?

Thank You


Solution

  • The best solution i found was to use a Filter to process the incoming response header.

    public class HeaderFilter implements ClientResponseFilter {
    
    
      private Map<String, String> headers = new HashMap<>();
    
      private List<String> headerFilter = new ArrayList<>();
    
    
      public final void addHeaderFilter(final String header) {
    
          headerFilter.add(header);
      }
    
      public final void removeHeaderFilter(final String header) {
    
          headerFilter.remove(header);
      }
    
      public final String getHeader(final String header) {
    
          return headers.get(header);
      }
    
      @Override
      public final void filter(final ClientRequestContext requestContext,
              final ClientResponseContext responseContext) 
                                          throws IOException {
    
          headers = new HashMap<>();
    
          for (String headerToLookFor : headerFilter) {
    
              String header = responseContext.getHeaderString(headerToLookFor);
    
              if (header != null) {
    
                  headers.put(headerToLookFor, header);
              } else {
    
                  ...
              }
          }
      }
    }