--- a/src/java.base/share/classes/javax/security/auth/callback/PasswordCallback.java	Thu Dec 13 16:14:07 2018 +0100
+++ b/src/java.base/share/classes/javax/security/auth/callback/PasswordCallback.java	Thu Dec 13 15:31:05 2018 +0100
@@ -67,7 +67,7 @@
      *                  if {@code prompt} has a length of 0.
      */
     public PasswordCallback(String prompt, boolean echoOn) {
-        if (prompt == null || prompt.length() == 0)
+        if (prompt == null || prompt.isEmpty())
             throw new IllegalArgumentException();
 
         this.prompt = prompt;