diff -r 000000000000 -r 8e220093e4bf samples/singletons/src/org/apidesign/singletons/api/DialogDisplayer.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/samples/singletons/src/org/apidesign/singletons/api/DialogDisplayer.java	Wed Jan 27 18:30:57 2010 +0100
@@ -0,0 +1,60 @@
+package org.apidesign.singletons.api;
+
+import java.util.Iterator;
+import java.util.ServiceLoader;
+import org.openide.util.Lookup;
+
+// BEGIN: singletons.injectable.api
+public abstract class DialogDisplayer {
+    protected DialogDisplayer() {
+    }
+
+    /** Ask user a question.
+     *
+     * @param query the text of the question
+     * @return true if user confirmed or false if declined
+     */
+    public abstract boolean yesOrNo(String query);
+
+    public static DialogDisplayer getDefault() {
+        return Impl.DEFAULT;
+    }
+    // FINISH: singletons.injectable.api
+
+
+    // BEGIN: singletons.injectable.dummyimpl
+    private static final class Impl extends DialogDisplayer {
+        private static final DialogDisplayer DEFAULT = initialize();
+        
+        @Override
+        public boolean yesOrNo(String query) {
+            System.err.printf("Saying no to '%s'\n", query);
+            return false;
+        }
+        // FINISH: singletons.injectable.dummyimpl
+
+        private static DialogDisplayer initialize() {
+            if (Boolean.getBoolean("singleton.jdk6")) {
+                return initializeServiceLoader();
+            } else {
+                return initializeLookup();
+            }
+        }
+        
+        // BEGIN: singletons.injectable.serviceloader
+        private static DialogDisplayer initializeServiceLoader() {
+            // see http://singletons.apidesign.org
+            Iterator<DialogDisplayer> it = null;
+            it = ServiceLoader.load(DialogDisplayer.class).iterator();
+            return it != null && it.hasNext() ? it.next() : new Impl();
+        }
+        // END: singletons.injectable.serviceloader
+
+        // BEGIN: singletons.injectable.lookup
+        private static DialogDisplayer initializeLookup() {
+            DialogDisplayer def = Lookup.getDefault().lookup(DialogDisplayer.class);
+            return def != null ? def : new Impl();
+        }
+        // END: singletons.injectable.lookup
+    }
+}