--- a/src/java.base/share/classes/javax/security/auth/callback/TextOutputCallback.java	Thu Dec 13 16:14:07 2018 +0100
+++ b/src/java.base/share/classes/javax/security/auth/callback/TextOutputCallback.java	Thu Dec 13 15:31:05 2018 +0100
@@ -74,7 +74,7 @@
     public TextOutputCallback(int messageType, String message) {
         if ((messageType != INFORMATION &&
                 messageType != WARNING && messageType != ERROR) ||
-            message == null || message.length() == 0)
+            message == null || message.isEmpty())
             throw new IllegalArgumentException();
 
         this.messageType = messageType;