--- /dev/null	2020-01-10 16:22:15.000000000 -0800
+++ new/test/jdk/java/nio/MappedByteBuffer/AlignmentOffset.java	2020-01-10 16:22:15.000000000 -0800
@@ -0,0 +1,82 @@
+/*
+ * Copyright (c) 2020, 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.
+ */
+
+/* @test
+ * @bug 8230665
+ * @summary Test correct behavior of alignmentOffset()
+ */
+
+import java.io.IOException;
+import java.nio.MappedByteBuffer;
+import java.nio.channels.FileChannel;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+public class AlignmentOffset {
+
+    public static void main(String[] args) throws Throwable {
+        test();
+    }
+
+    private static void test() throws IOException {
+        MappedByteBuffer[] mbb = buffers();
+        int failures = 0;
+        for (MappedByteBuffer bb : mbb) {
+            try {
+                int offset = bb.alignmentOffset(1, 4);
+                if (offset >= 0) {
+                    System.out.println("PASSED");
+                } else {
+                    System.err.println("FAILED "+offset);
+                    failures++;
+                }
+            } catch (UnsupportedOperationException e) {
+                System.out.println("Not applicable, UOE thrown: ");
+            }
+        }
+        if (failures > 0) {
+            throw new RuntimeException("Test failed");
+        }
+    }
+
+    private static MappedByteBuffer[] buffers() throws IOException {
+        return new MappedByteBuffer[]{
+                createMBB(new byte[]{0, 1, 2, 3}),
+                createMBB(new byte[]{0, 1, 2, -3,
+                    45, 6, 7, 78, 3, -7, 6, 7, -128, 127}),
+        };
+    }
+
+    private static MappedByteBuffer createMBB(byte[] contents)
+        throws IOException {
+        Path tempFile = Files.createTempFile("mbb", null);
+        tempFile.toFile().deleteOnExit();
+        Files.write(tempFile, contents);
+        try (FileChannel fc = FileChannel.open(tempFile)) {
+            MappedByteBuffer map =
+                fc.map(FileChannel.MapMode.READ_ONLY, 0, contents.length);
+            map.load();
+            return map;
+        }
+    }
+}