--- old/src/jdk.scripting.nashorn.shell/share/classes/jdk/nashorn/tools/jjs/NashornCompleter.java	2015-08-25 16:46:42.046339300 +0530
+++ new/src/jdk.scripting.nashorn.shell/share/classes/jdk/nashorn/tools/jjs/NashornCompleter.java	2015-08-25 16:46:41.706338800 +0530
@@ -254,6 +254,11 @@
 
     // read file name from the user using by showing a swing file chooser diablog
     private static String readFileName(final PrintWriter err) {
+        // if running on AWT Headless mode, don't attempt swing dialog box!
+        if (Main.HEADLESS) {
+            return null;
+        }
+
         final FutureTask<String> fileChooserTask = new FutureTask<String>(() -> {
             // show a file chooser dialog box
             final JFileChooser chooser = new JFileChooser();