diff -r 000000000000 -r 373ffda63c9a src/share/jaxws_classes/com/sun/xml/internal/bind/v2/util/FlattenIterator.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/jaxws_classes/com/sun/xml/internal/bind/v2/util/FlattenIterator.java	Wed Apr 27 01:27:09 2016 +0800
@@ -0,0 +1,81 @@
+/*
+ * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package com.sun.xml.internal.bind.v2.util;
+
+import java.util.Iterator;
+import java.util.Map;
+import java.util.NoSuchElementException;
+
+/**
+ * {@link Iterator} that walks over a map of maps.
+ *
+ * @author Kohsuke Kawaguchi
+ * @since 2.0
+ */
+public final class FlattenIterator<T> implements Iterator<T> {
+
+    private final Iterator<? extends Map<?,? extends T>> parent;
+    private Iterator<? extends T> child = null;
+    private T next;
+
+    public FlattenIterator( Iterable<? extends Map<?,? extends T>> core ) {
+        this.parent = core.iterator();
+    }
+
+
+    public void remove() {
+        throw new UnsupportedOperationException();
+    }
+
+    public boolean hasNext() {
+        getNext();
+        return next!=null;
+    }
+
+    public T next() {
+        T r = next;
+        next = null;
+        if(r==null)
+            throw new NoSuchElementException();
+        return r;
+    }
+
+    private void getNext() {
+        if(next!=null)  return;
+
+        if(child!=null && child.hasNext()) {
+            next = child.next();
+            return;
+        }
+        // child is empty
+        if(parent.hasNext()) {
+            child = parent.next().values().iterator();
+            getNext();
+        }
+        // else
+        //      no more object
+    }
+}