--- a/src/java.base/share/classes/com/sun/net/ssl/TrustManagerFactory.java	Thu Dec 13 16:14:07 2018 +0100
+++ b/src/java.base/share/classes/com/sun/net/ssl/TrustManagerFactory.java	Thu Dec 13 15:31:05 2018 +0100
@@ -155,7 +155,7 @@
                                                  String provider)
         throws NoSuchAlgorithmException, NoSuchProviderException
     {
-        if (provider == null || provider.length() == 0)
+        if (provider == null || provider.isEmpty())
             throw new IllegalArgumentException("missing provider");
         Object[] objs = SSLSecurity.getImpl(algorithm, "TrustManagerFactory",
                                             provider);