JsonPatchInterceptor.java

//package ameba.core.ws.rs;
//
//import ameba.message.internal.MediaType;
//import com.fasterxml.jackson.databind.JsonNode;
//import com.fasterxml.jackson.databind.ObjectMapper;
//import com.github.fge.jsonpatch.JsonPatch;
//import com.github.fge.jsonpatch.JsonPatchException;
//import org.glassfish.jersey.message.MessageBodyWorkers;
//
//import javax.inject.Inject;
//import javax.ws.rs.GET;
//import javax.ws.rs.InternalServerErrorException;
//import javax.ws.rs.WebApplicationException;
//import javax.ws.rs.core.Context;
//import javax.ws.rs.core.MultivaluedHashMap;
//import javax.ws.rs.core.UriInfo;
//import javax.ws.rs.ext.MessageBodyWriter;
//import javax.ws.rs.ext.ReaderInterceptor;
//import javax.ws.rs.ext.ReaderInterceptorContext;
//import java.io.ByteArrayInputStream;
//import java.io.ByteArrayOutputStream;
//import java.io.IOException;
//import java.lang.annotation.Annotation;
//import java.lang.reflect.Method;
//
///**
// * <p>JsonPatchInterceptor class.</p>
// *
// * @author icode
// * @since 0.1.6e
// */
//@PATCH
//public class JsonPatchInterceptor implements ReaderInterceptor {
//
//    private final UriInfo uriInfo;
//    private final MessageBodyWorkers workers;
//    @Inject
//    private ObjectMapper mapper;
//
//    /**
//     * {@code PatchingInterceptor} injection constructor.
//     *
//     * @param uriInfo {@code javax.ws.rs.core.UriInfo} proxy instance.
//     * @param workers {@link org.glassfish.jersey.message.MessageBodyWorkers} message body workers.
//     */
//    public JsonPatchInterceptor(@Context UriInfo uriInfo, @Context MessageBodyWorkers workers) {
//        this.uriInfo = uriInfo;
//        this.workers = workers;
//    }
//
//    /**
//     * {@inheritDoc}
//     */
//    @SuppressWarnings("unchecked")
//    @Override
//    public Object aroundReadFrom(ReaderInterceptorContext readerInterceptorContext) throws IOException, WebApplicationException {
//        if (!MediaType.APPLICATION_JSON_PATCH_TYPE.equals(readerInterceptorContext.getMediaType())) {
//            return readerInterceptorContext.proceed();
//        }
//
//        // Get the resource we are being called on, and find the GET method
//        Object resource = uriInfo.getMatchedResources().get(0);
//
//        Method found = null;
//        for (Method next : resource.getClass().getMethods()) {
//            if (next.getAnnotation(GET.class) != null) {
//                found = next;
//                break;
//            }
//        }
//
//        if (found == null) {
//            throw new InternalServerErrorException("No matching GET method on resource");
//        }
//
//        // Invoke the get method to get the state we are trying to patch
//        Object bean;
//        try {
//            bean = found.invoke(resource);
//        } catch (Exception e) {
//            throw new WebApplicationException(e);
//        }
//
//        // Convert this object to a an array of bytes
//        ByteArrayOutputStream baos = new ByteArrayOutputStream();
//        MessageBodyWriter bodyWriter =
//                workers.getMessageBodyWriter(bean.getClass(), bean.getClass(),
//                        new Annotation[0], MediaType.APPLICATION_JSON_TYPE);
//
//        bodyWriter.writeTo(bean, bean.getClass(), bean.getClass(),
//                new Annotation[0], MediaType.APPLICATION_JSON_TYPE,
//                new MultivaluedHashMap<String, Object>(), baos);
//
//
//        // Use the Jackson 2.x classes to convert both the incoming patch
//        // and the current state of the object into a JsonNode / JsonPatch
//        JsonNode serverState = mapper.readValue(baos.toByteArray(), JsonNode.class);
//        JsonNode patchAsNode = mapper.readValue(readerInterceptorContext.getInputStream(), JsonNode.class);
//        JsonPatch patch = JsonPatch.fromJson(patchAsNode);
//
//        try {
//            // Apply the patch
//            JsonNode result = patch.apply(serverState);
//
//            // Stream the result & modify the stream on the readerInterceptor
//            ByteArrayOutputStream resultAsByteArray = new ByteArrayOutputStream();
//            mapper.writeValue(resultAsByteArray, result);
//            readerInterceptorContext.setInputStream(new ByteArrayInputStream(resultAsByteArray.toByteArray()));
//
//            // Pass control back to the Jersey code
//            return readerInterceptorContext.proceed();
//        } catch (JsonPatchException ex) {
//            throw new InternalServerErrorException("Error applying patch.", ex);
//        }
//    }
//}