--- a/src/java.base/share/classes/sun/net/TransferProtocolClient.java	Thu Dec 13 16:14:07 2018 +0100
+++ b/src/java.base/share/classes/sun/net/TransferProtocolClient.java	Thu Dec 13 15:31:05 2018 +0100
@@ -76,7 +76,7 @@
                 System.out.print(response);
             }
 
-            if (response.length() == 0) {
+            if (response.isEmpty()) {
                 code = -1;
             } else {
                 try {