From 3fdbeeeccb6a5fcfd1fc18b0aa0aa2a3c2f08370 Mon Sep 17 00:00:00 2001
From: "luca.frosini" <luca.frosini@isti.cnr.it>
Date: Tue, 28 Mar 2017 14:00:32 +0000
Subject: [PATCH] Fixed HEAD http request management

git-svn-id: https://svn.d4science.research-infrastructures.eu/gcube/trunk/information-system/resource-registry-api@146395 82a268e6-3cf1-43bd-a215-b396298e98cf
---
 .../api/rest/httputils/HTTPCall.java          | 50 +++++++++++++++----
 1 file changed, 40 insertions(+), 10 deletions(-)

diff --git a/src/main/java/org/gcube/informationsystem/resourceregistry/api/rest/httputils/HTTPCall.java b/src/main/java/org/gcube/informationsystem/resourceregistry/api/rest/httputils/HTTPCall.java
index 42ac9a7..f6212ef 100644
--- a/src/main/java/org/gcube/informationsystem/resourceregistry/api/rest/httputils/HTTPCall.java
+++ b/src/main/java/org/gcube/informationsystem/resourceregistry/api/rest/httputils/HTTPCall.java
@@ -15,8 +15,15 @@ import org.gcube.common.authorization.library.provider.SecurityTokenProvider;
 import org.gcube.common.scope.api.ScopeProvider;
 import org.gcube.informationsystem.impl.utils.ISMapper;
 import org.gcube.informationsystem.model.ISManageable;
+import org.gcube.informationsystem.model.entity.Facet;
+import org.gcube.informationsystem.model.entity.Resource;
+import org.gcube.informationsystem.model.relation.Relation;
 import org.gcube.informationsystem.resourceregistry.api.exceptions.ExceptionMapper;
 import org.gcube.informationsystem.resourceregistry.api.exceptions.ResourceRegistryException;
+import org.gcube.informationsystem.resourceregistry.api.exceptions.entity.facet.FacetNotFoundException;
+import org.gcube.informationsystem.resourceregistry.api.exceptions.entity.resource.ResourceNotFoundException;
+import org.gcube.informationsystem.resourceregistry.api.exceptions.er.ERNotFoundException;
+import org.gcube.informationsystem.resourceregistry.api.exceptions.relation.RelationNotFoundException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -28,7 +35,7 @@ public class HTTPCall<C> {
 	public static final String APPLICATION_JSON_CHARSET_UTF_8 = "application/json;charset=UTF-8";
 	
 	public enum HTTPMETHOD {
-		GET, POST, PUT, DELETE;
+		HEAD, GET, POST, PUT, DELETE;
 
 		@Override
 		public String toString() {
@@ -172,6 +179,21 @@ public class HTTPCall<C> {
 		return result;
 	}
 	
+	protected void throwElementNotFoundException(Class<C> clz)
+			throws ERNotFoundException, ResourceRegistryException {
+		
+		String error = String.format("Requested %s instance was not found", clz.getSimpleName());
+		
+		if (Resource.class.isAssignableFrom(clz)) {
+			throw new ResourceNotFoundException(error);
+		} else if (Facet.class.isAssignableFrom(clz)) {
+			throw new FacetNotFoundException(error);
+		} else if (Relation.class.isAssignableFrom(clz)) {
+			throw new RelationNotFoundException(error);
+		}
+
+	}
+	
 	@SuppressWarnings("unchecked")
 	public C call(Class<C> clz, URL url, String userAgent) throws Exception {
 		HttpURLConnection connection = getConnection(url, userAgent);
@@ -179,13 +201,25 @@ public class HTTPCall<C> {
 		String responseMessage = connection.getResponseMessage();
 		int responseCode  = connection.getResponseCode();
 		
+		logger.debug("Response code for {} {} is {} : {}",
+				method, connection.getURL(), responseCode,
+				responseMessage);
+		
+		if(method == HTTPMETHOD.HEAD){
+			if(responseCode == HttpURLConnection.HTTP_NO_CONTENT){
+				return null;
+			}
+			if(responseCode == HttpURLConnection.HTTP_NOT_FOUND){
+				throwElementNotFoundException(clz);
+			}
+		}
+		
+		
 		if (responseCode != HttpURLConnection.HTTP_OK) {
 			
-			logger.error("Response code for {} is {} : {}",
-					connection.getURL(), responseCode,
-					responseMessage);
+			InputStream inputStream = connection.getErrorStream();
+			StringBuilder result = getStringBuilder(inputStream);
 			
-			StringBuilder result = getStringBuilder(connection.getErrorStream());
 			String res = result.toString();
 			
 			ResourceRegistryException rre = null;
@@ -197,12 +231,8 @@ public class HTTPCall<C> {
 			
 			throw rre;
 			
-		}else{
-			logger.debug("Response code for {} is {} : {}",
-					connection.getURL(), responseCode,
-					responseMessage);
 		}
-
+		
 		StringBuilder result = getStringBuilder(connection.getInputStream());
 
 		String res = result.toString();