enables retry on connection drop

src/main/java/com/microsoft/graph/http/CoreHttpProvider.java

@@ -31,6 +31,7 @@
 import java.io.UnsupportedEncodingException;
 import java.net.URL;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -58,6 +59,7 @@
 import okhttp3.Headers;
 import okhttp3.MediaType;
 import okhttp3.OkHttpClient;
+import okhttp3.Protocol;
 import okhttp3.Request;
 import okhttp3.RequestBody;
 import okhttp3.Response;
@@ -356,21 +358,24 @@ private <Result, Body, DeserializeType> Result sendRequestInternal(final IHttpRe
 					throws ClientException {
 
 		try {
+			if(this.connectionConfig == null) {
+				this.connectionConfig = new DefaultConnectionConfig();
+			}
 			if(this.corehttpClient == null) {
-				OkHttpClient.Builder okBuilder = HttpClients.createDefault(new ICoreAuthenticationProvider() {
+				final ICoreAuthenticationProvider authProvider = new ICoreAuthenticationProvider() {
 					@Override
 					public Request authenticateRequest(Request request) {
 						return request;
 					}
-				}).newBuilder();
-				if(this.connectionConfig == null) {
-					this.connectionConfig = new DefaultConnectionConfig();
-				}
-				okBuilder.connectTimeout(connectionConfig.getConnectTimeout(), TimeUnit.MILLISECONDS);
-				okBuilder.readTimeout(connectionConfig.getReadTimeout(), TimeUnit.MILLISECONDS);
-				okBuilder.followRedirects(false);
-				okBuilder.retryOnConnectionFailure(false);
-				this.corehttpClient = okBuilder.build();
+				};
+				this.corehttpClient = HttpClients
+									.createDefault(authProvider)
+									.newBuilder()
+									.connectTimeout(connectionConfig.getConnectTimeout(), TimeUnit.MILLISECONDS)
+									.readTimeout(connectionConfig.getReadTimeout(), TimeUnit.MILLISECONDS)
+									.followRedirects(false)
+									.protocols(Arrays.asList(Protocol.HTTP_1_1)) //https://stackoverflow.com/questions/62031298/sockettimeout-on-java-11-but-not-on-java-8
+									.build();
 			}
 			if (authenticationProvider != null) {
 				authenticationProvider.authenticateRequest(request);

src/test/java/com/microsoft/graph/functional/BatchTests.java

@@ -68,6 +68,7 @@ public void GetsABatchFromRequests() throws IOException{
         assertEquals(200, batchResponse.code());
 
         final MSBatchResponseContent responseContent = new MSBatchResponseContent(batchResponse);
+        batchResponse.close();
 
         assertEquals(400, responseContent.getResponseById(userPostId).code()); //400:we're not providing enough properties for the call to go through
         assertEquals(200, responseContent.getResponseById(meGetId).code());

src/test/java/com/microsoft/graph/functional/UserTests.java

@@ -1,5 +1,6 @@
 package com.microsoft.graph.functional;
 
+import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 
@@ -8,6 +9,9 @@
 import java.io.InputStream;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
 
 import org.junit.Before;
 import org.junit.Ignore;
@@ -31,7 +35,6 @@
 import com.microsoft.graph.requests.extensions.IOrganizationCollectionPage;
 import com.microsoft.graph.requests.extensions.IUsedInsightCollectionPage;
 import com.microsoft.graph.requests.extensions.IUserCollectionPage;
-
 @Ignore
 public class UserTests {
 	IGraphServiceClient graphServiceClient = null;
@@ -170,6 +173,27 @@ public void meMemberof() {
 		IDirectoryObjectCollectionWithReferencesPage page = graphServiceClient.me().memberOf().buildRequest().get();
 		assertNotNull(page);
 	}
+	@Test
+	public void getMeAndRetryOnThrottling() throws Exception {
+		ExecutorService exec = Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors() * 2);
+		try {
+			for(Integer i = 0; i < 2000; i++) {
+				exec.submit(new Runnable() {
+					@Override
+					public void run() {
+						final IUserCollectionPage users = graphServiceClient.users().buildRequest().get();
+						assertNotNull(users);
+						final List<User> currentPage = users.getCurrentPage();
+						assertNotNull(currentPage);
+						assertNotEquals(0, currentPage.size());
+					}
+				});
+			}
+			exec.awaitTermination(5L, TimeUnit.MINUTES);
+		} finally {
+			exec.shutdown();
+		}
+	}
 
 	@Test
 	public void emptyPostContentType() {