diff -r 4ebc2e2fb97c -r 71c04702a3d5 src/java.base/macosx/classes/sun/nio/fs/UTIFileTypeDetector.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/macosx/classes/sun/nio/fs/UTIFileTypeDetector.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2015, 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 sun.nio.fs;
+
+import java.io.IOException;
+import java.nio.file.Path;
+import java.security.AccessController;
+import java.security.PrivilegedAction;
+
+/**
+ * File type detector that uses a file extension to look up its MIME type
+ * via the Apple Uniform Type Identifier interfaces.
+ */
+class UTIFileTypeDetector extends AbstractFileTypeDetector {
+    UTIFileTypeDetector() {
+        super();
+    }
+
+    private native String probe0(String fileExtension) throws IOException;
+
+    @Override
+    protected String implProbeContentType(Path path) throws IOException {
+        Path fn = path.getFileName();
+        if (fn == null)
+            return null;  // no file name
+
+        String ext = getExtension(fn.toString());
+        if (ext.isEmpty())
+            return null;  // no extension
+
+        return probe0(ext);
+    }
+
+    static {
+        AccessController.doPrivileged(new PrivilegedAction<>() {
+            @Override
+            public Void run() {
+                System.loadLibrary("nio");
+                return null;
+            }
+        });
+    }
+}