1 /*
   2  * Copyright (c) 2009, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package jdk.nio.zipfs;
  27 
  28 import java.nio.ByteBuffer;
  29 import java.nio.CharBuffer;
  30 import java.nio.charset.Charset;
  31 import java.nio.charset.CharsetDecoder;
  32 import java.nio.charset.CharsetEncoder;
  33 import java.nio.charset.CoderResult;
  34 import java.nio.charset.CodingErrorAction;
  35 import java.util.Arrays;
  36 
  37 import static java.nio.charset.StandardCharsets.ISO_8859_1;
  38 import static java.nio.charset.StandardCharsets.UTF_8;
  39 
  40 /**
  41  * Utility class for zipfile name and comment decoding and encoding
  42  *
  43  * @author Xueming Shen
  44  */
  45 class ZipCoder {
  46 
  47     static class UTF8 extends ZipCoder {
  48         UTF8() {
  49             super(UTF_8);
  50         }
  51 
  52         @Override
  53         byte[] getBytes(String s) {        // fast pass for ascii
  54             for (int i = 0; i < s.length(); i++) {
  55                 if (s.charAt(i) > 0x7f) return super.getBytes(s);
  56             }
  57             return s.getBytes(ISO_8859_1);
  58         }
  59 
  60         @Override
  61         String toString(byte[] ba) {
  62             for (byte b : ba) {
  63                 if (b < 0) return super.toString(ba);
  64             }
  65             return new String(ba, ISO_8859_1);
  66         }
  67     }
  68 
  69     private static final ZipCoder utf8 = new UTF8();
  70 
  71     public static ZipCoder get(String csn) {
  72         Charset cs = Charset.forName(csn);
  73         if (cs.name().equals("UTF-8")) {
  74             return utf8;
  75         }
  76         return new ZipCoder(cs);
  77     }
  78 
  79     String toString(byte[] ba) {
  80         CharsetDecoder cd = decoder().reset();
  81         int clen = (int)(ba.length * cd.maxCharsPerByte());
  82         char[] ca = new char[clen];
  83         if (clen == 0)
  84             return new String(ca);
  85         ByteBuffer bb = ByteBuffer.wrap(ba, 0, ba.length);
  86         CharBuffer cb = CharBuffer.wrap(ca);
  87         CoderResult cr = cd.decode(bb, cb, true);
  88         if (!cr.isUnderflow())
  89             throw new IllegalArgumentException(cr.toString());
  90         cr = cd.flush(cb);
  91         if (!cr.isUnderflow())
  92             throw new IllegalArgumentException(cr.toString());
  93         return new String(ca, 0, cb.position());
  94     }
  95 
  96     byte[] getBytes(String s) {
  97         CharsetEncoder ce = encoder().reset();
  98         char[] ca = s.toCharArray();
  99         int len = (int)(ca.length * ce.maxBytesPerChar());
 100         byte[] ba = new byte[len];
 101         if (len == 0)
 102             return ba;
 103         ByteBuffer bb = ByteBuffer.wrap(ba);
 104         CharBuffer cb = CharBuffer.wrap(ca);
 105         CoderResult cr = ce.encode(cb, bb, true);
 106         if (!cr.isUnderflow())
 107             throw new IllegalArgumentException(cr.toString());
 108         cr = ce.flush(bb);
 109         if (!cr.isUnderflow())
 110             throw new IllegalArgumentException(cr.toString());
 111         if (bb.position() == ba.length)  // defensive copy?
 112             return ba;
 113         else
 114             return Arrays.copyOf(ba, bb.position());
 115     }
 116 
 117     boolean isUTF8() {
 118         return cs == UTF_8;
 119     }
 120 
 121     private Charset cs;
 122 
 123     private ZipCoder(Charset cs) {
 124         this.cs = cs;
 125     }
 126 
 127     private final ThreadLocal<CharsetDecoder> decTL = new ThreadLocal<>();
 128     private final ThreadLocal<CharsetEncoder> encTL = new ThreadLocal<>();
 129 
 130     private CharsetDecoder decoder() {
 131         CharsetDecoder dec = decTL.get();
 132         if (dec == null) {
 133         dec = cs.newDecoder()
 134             .onMalformedInput(CodingErrorAction.REPORT)
 135             .onUnmappableCharacter(CodingErrorAction.REPORT);
 136         decTL.set(dec);
 137         }
 138         return dec;
 139     }
 140 
 141     private CharsetEncoder encoder() {
 142         CharsetEncoder enc = encTL.get();
 143         if (enc == null) {
 144         enc = cs.newEncoder()
 145             .onMalformedInput(CodingErrorAction.REPORT)
 146             .onUnmappableCharacter(CodingErrorAction.REPORT);
 147         encTL.set(enc);
 148         }
 149         return enc;
 150     }
 151 }