HTTP cache protocol interceptors to route requests that cannot be correctly represented as SimpleHttpRequest directly to the request execution pipeline bypassing the caching layer

Author: ok2c

httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/AsyncCachingExec.java

@@ -72,7 +72,6 @@
 import org.apache.hc.core5.http.HttpRequest;
 import org.apache.hc.core5.http.HttpResponse;
 import org.apache.hc.core5.http.HttpStatus;
-import org.apache.hc.core5.http.ProtocolException;
 import org.apache.hc.core5.http.impl.BasicEntityDetails;
 import org.apache.hc.core5.http.nio.AsyncDataConsumer;
 import org.apache.hc.core5.http.nio.AsyncEntityProducer;
@@ -261,11 +260,10 @@ public void doExecute(
             return;
         }
 
-        // Do not attempt to cache requests with an enclosed content body
-        // To be revised when implementing QUERY support
-        if (entityProducer != null) {
+        final SimpleHttpRequest cacheRequest = prepareRequest(request, entityProducer);
+        if (cacheRequest == null) {
             if (LOG.isDebugEnabled()) {
-                LOG.debug("{} entity enclosing request cannot be served from cache", exchangeId);
+                LOG.debug("{} request cannot be correctly executed and cached", exchangeId);
             }
             chain.proceed(request, entityProducer, scope, asyncExecCallback);
             return;
@@ -284,8 +282,6 @@ public void doExecute(
             LOG.debug("{} request cache control: {}", exchangeId, requestCacheControl);
         }
 
-        final SimpleHttpRequest cacheRequest = prepareRequest(request, entityProducer);
-
         if (!cacheableRequestPolicy.canBeServedFromCache(requestCacheControl, cacheRequest)) {
             if (LOG.isDebugEnabled()) {
                 LOG.debug("{} request cannot be served from cache", exchangeId);
@@ -416,10 +412,10 @@ public void cancelled() {
     }
 
     SimpleHttpRequest prepareRequest(final HttpRequest request,
-                                     final AsyncEntityProducer entityProducer) throws ProtocolException {
+                                     final AsyncEntityProducer entityProducer) {
         // To be revised when implementing QUERY support
         if (entityProducer != null) {
-            throw new ProtocolException("Caching of entity enclosing requests is not supported");
+            return null;
         }
         return SimpleRequestBuilder.copy(request).build();
     }

httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/CachingExec.java

@@ -61,7 +61,6 @@
 import org.apache.hc.core5.http.HttpHost;
 import org.apache.hc.core5.http.HttpStatus;
 import org.apache.hc.core5.http.HttpVersion;
-import org.apache.hc.core5.http.ProtocolException;
 import org.apache.hc.core5.http.io.entity.ByteArrayEntity;
 import org.apache.hc.core5.http.io.entity.EntityUtils;
 import org.apache.hc.core5.http.io.entity.StringEntity;
@@ -158,12 +157,10 @@ ClassicHttpResponse doExecute(
             return new BasicClassicHttpResponse(HttpStatus.SC_NOT_IMPLEMENTED);
         }
 
-        // Do not attempt to cache requests with an enclosed content body
-        // To be revised when implementing QUERY support
-        final HttpEntity requestEntity = request.getEntity();
-        if (requestEntity != null) {
+        final SimpleHttpRequest cacheRequest = prepareRequest(request);
+        if (cacheRequest == null) {
             if (LOG.isDebugEnabled()) {
-                LOG.debug("{} entity enclosing request cannot be served from cache", exchangeId);
+                LOG.debug("{} request cannot be correctly executed and cached", exchangeId);
             }
             return chain.proceed(request, scope);
         }
@@ -176,8 +173,6 @@ ClassicHttpResponse doExecute(
             CacheControlHeaderGenerator.INSTANCE.generate(requestCacheControl, request);
         }
 
-        final SimpleHttpRequest cacheRequest = prepareRequest(request);
-
         if (LOG.isDebugEnabled()) {
             LOG.debug("Request cache control: {}", requestCacheControl);
         }
@@ -226,10 +221,10 @@ private static ClassicHttpResponse convert(final SimpleHttpResponse cacheRespons
         return response;
     }
 
-    SimpleHttpRequest prepareRequest(final ClassicHttpRequest request) throws ProtocolException {
+    SimpleHttpRequest prepareRequest(final ClassicHttpRequest request) {
         // To be revised when implementing QUERY support
         if (request.getEntity() != null) {
-            throw new ProtocolException("Caching of entity enclosing requests is not supported");
+            return null;
         }
         return SimpleRequestBuilder.copy(request).build();
     }