--- a/src/java.base/share/classes/java/security/KeyStore.java	Thu Dec 13 16:14:07 2018 +0100
+++ b/src/java.base/share/classes/java/security/KeyStore.java	Thu Dec 13 15:31:05 2018 +0100
@@ -913,7 +913,7 @@
         throws KeyStoreException, NoSuchProviderException
     {
         Objects.requireNonNull(type, "null type name");
-        if (provider == null || provider.length() == 0)
+        if (provider == null || provider.isEmpty())
             throw new IllegalArgumentException("missing provider");
         try {
             Object[] objs = Security.getImpl(type, "KeyStore", provider);