--- /dev/null	2018-04-28 00:26:07.190086997 -0400
+++ new/test/hotspot/jtreg/runtime/Nestmates/NestmatesJNI.java	2018-06-20 01:01:31.967625489 -0400
@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2018, 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.
+ *
+ * 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.
+ */
+
+/**
+ * Utility class for invoking methods and constructors and accessing fields
+ * via JNI.
+ */
+public class NestmatesJNI {
+
+    static {
+        System.loadLibrary("NestmatesJNI");
+    }
+
+    public static native void callVoidVoid(Object target, String definingClassName, String methodName, boolean virtual);
+
+    public static native String callStringVoid(Object target, String definingClassName, String methodName, boolean virtual);
+
+    public static native void callStaticVoidVoid(String definingClassName, String methodName);
+
+    public static Object newInstance(String definingClassName, String sig, Object outerThis) {
+        return newInstance0(definingClassName, "<init>", sig, outerThis);
+    }
+
+    private static native Object newInstance0(String definingClassName, String method_name, String sig, Object outerThis);
+
+    public static native int getIntField(Object target, String definingClassName, String fieldName);
+
+    public static native void setIntField(Object target, String definingClassName, String fieldName, int newVal);
+
+    public static native int getStaticIntField(String definingClassName, String fieldName);
+
+    public static native void setStaticIntField(String definingClassName, String fieldName, int newVal);
+
+}