--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.zipfs/share/classes/jdk/nio/zipfs/ZipCoder.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,152 @@
+/*
+ * Copyright (c) 2009, 2017, 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 jdk.nio.zipfs;
+
+import java.nio.ByteBuffer;
+import java.nio.CharBuffer;
+import java.nio.charset.Charset;
+import java.nio.charset.CharsetDecoder;
+import java.nio.charset.CharsetEncoder;
+import java.nio.charset.CoderResult;
+import java.nio.charset.CodingErrorAction;
+import java.util.Arrays;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+import static java.nio.charset.StandardCharsets.ISO_8859_1;
+
+/**
+ * Utility class for zipfile name and comment decoding and encoding
+ *
+ * @author  Xueming Shen
+ */
+
+class ZipCoder {
+
+    static class UTF8 extends ZipCoder {
+        UTF8() {
+            super(UTF_8);
+        }
+
+        @Override
+        byte[] getBytes(String s) {        // fast pass for ascii
+            for (int i = 0; i < s.length(); i++) {
+                if (s.charAt(i) > 0x7f) return super.getBytes(s);
+            }
+            return s.getBytes(ISO_8859_1);
+        }
+
+        @Override
+        String toString(byte[] ba) {
+            for (byte b : ba) {
+                if (b < 0) return super.toString(ba);
+            }
+            return new String(ba, ISO_8859_1);
+        }
+    }
+
+    private static final ZipCoder utf8 = new UTF8();
+
+    public static ZipCoder get(String csn) {
+        Charset cs = Charset.forName(csn);
+        if (cs.name().equals("UTF-8")) {
+            return utf8;
+        }
+        return new ZipCoder(cs);
+    }
+
+    String toString(byte[] ba) {
+        CharsetDecoder cd = decoder().reset();
+        int clen = (int)(ba.length * cd.maxCharsPerByte());
+        char[] ca = new char[clen];
+        if (clen == 0)
+            return new String(ca);
+        ByteBuffer bb = ByteBuffer.wrap(ba, 0, ba.length);
+        CharBuffer cb = CharBuffer.wrap(ca);
+        CoderResult cr = cd.decode(bb, cb, true);
+        if (!cr.isUnderflow())
+            throw new IllegalArgumentException(cr.toString());
+        cr = cd.flush(cb);
+        if (!cr.isUnderflow())
+            throw new IllegalArgumentException(cr.toString());
+        return new String(ca, 0, cb.position());
+    }
+
+    byte[] getBytes(String s) {
+        CharsetEncoder ce = encoder().reset();
+        char[] ca = s.toCharArray();
+        int len = (int)(ca.length * ce.maxBytesPerChar());
+        byte[] ba = new byte[len];
+        if (len == 0)
+            return ba;
+        ByteBuffer bb = ByteBuffer.wrap(ba);
+        CharBuffer cb = CharBuffer.wrap(ca);
+        CoderResult cr = ce.encode(cb, bb, true);
+        if (!cr.isUnderflow())
+            throw new IllegalArgumentException(cr.toString());
+        cr = ce.flush(bb);
+        if (!cr.isUnderflow())
+            throw new IllegalArgumentException(cr.toString());
+        if (bb.position() == ba.length)  // defensive copy?
+            return ba;
+        else
+            return Arrays.copyOf(ba, bb.position());
+    }
+
+    boolean isUTF8() {
+        return cs == UTF_8;
+    }
+
+    private Charset cs;
+
+    private ZipCoder(Charset cs) {
+        this.cs = cs;
+    }
+
+    private final ThreadLocal<CharsetDecoder> decTL = new ThreadLocal<>();
+    private final ThreadLocal<CharsetEncoder> encTL = new ThreadLocal<>();
+
+    private CharsetDecoder decoder() {
+        CharsetDecoder dec = decTL.get();
+        if (dec == null) {
+        dec = cs.newDecoder()
+            .onMalformedInput(CodingErrorAction.REPORT)
+            .onUnmappableCharacter(CodingErrorAction.REPORT);
+        decTL.set(dec);
+        }
+        return dec;
+    }
+
+    private CharsetEncoder encoder() {
+        CharsetEncoder enc = encTL.get();
+        if (enc == null) {
+        enc = cs.newEncoder()
+            .onMalformedInput(CodingErrorAction.REPORT)
+            .onUnmappableCharacter(CodingErrorAction.REPORT);
+        encTL.set(enc);
+        }
+        return enc;
+    }
+}