--- a/src/java.base/share/classes/java/lang/Long.java	Thu Dec 13 16:14:07 2018 +0100
+++ b/src/java.base/share/classes/java/lang/Long.java	Thu Dec 13 15:31:05 2018 +0100
@@ -1248,7 +1248,7 @@
         boolean negative = false;
         Long result;
 
-        if (nm.length() == 0)
+        if (nm.isEmpty())
             throw new NumberFormatException("Zero length string");
         char firstChar = nm.charAt(0);
         // Handle sign, if present