1 /*
   2  * Copyright (c) 2009, 2014, 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 /**
  38  * Utility class for zipfile name and comment decoding and encoding
  39  *
  40  * @author  Xueming Shen
  41  */
  42 
  43 final class ZipCoder {
  44 
  45     String toString(byte[] ba, int length) {
  46         CharsetDecoder cd = decoder().reset();
  47         int len = (int)(length * cd.maxCharsPerByte());
  48         char[] ca = new char[len];
  49         if (len == 0)
  50             return new String(ca);
  51         ByteBuffer bb = ByteBuffer.wrap(ba, 0, length);
  52         CharBuffer cb = CharBuffer.wrap(ca);
  53         CoderResult cr = cd.decode(bb, cb, true);
  54         if (!cr.isUnderflow())
  55             throw new IllegalArgumentException(cr.toString());
  56         cr = cd.flush(cb);
  57         if (!cr.isUnderflow())
  58             throw new IllegalArgumentException(cr.toString());
  59         return new String(ca, 0, cb.position());
  60     }
  61 
  62     String toString(byte[] ba) {
  63         return toString(ba, ba.length);
  64     }
  65 
  66     byte[] getBytes(String s) {
  67         CharsetEncoder ce = encoder().reset();
  68         char[] ca = s.toCharArray();
  69         int len = (int)(ca.length * ce.maxBytesPerChar());
  70         byte[] ba = new byte[len];
  71         if (len == 0)
  72             return ba;
  73         ByteBuffer bb = ByteBuffer.wrap(ba);
  74         CharBuffer cb = CharBuffer.wrap(ca);
  75         CoderResult cr = ce.encode(cb, bb, true);
  76         if (!cr.isUnderflow())
  77             throw new IllegalArgumentException(cr.toString());
  78         cr = ce.flush(bb);
  79         if (!cr.isUnderflow())
  80             throw new IllegalArgumentException(cr.toString());
  81         if (bb.position() == ba.length)  // defensive copy?
  82             return ba;
  83         else
  84             return Arrays.copyOf(ba, bb.position());
  85     }
  86 
  87     // assume invoked only if "this" is not utf8
  88     byte[] getBytesUTF8(String s) {
  89         if (isutf8)
  90             return getBytes(s);
  91         if (utf8 == null)
  92             utf8 = new ZipCoder(Charset.forName("UTF-8"));
  93         return utf8.getBytes(s);
  94     }
  95 
  96     String toStringUTF8(byte[] ba, int len) {
  97         if (isutf8)
  98             return toString(ba, len);
  99         if (utf8 == null)
 100             utf8 = new ZipCoder(Charset.forName("UTF-8"));
 101         return utf8.toString(ba, len);
 102     }
 103 
 104     boolean isUTF8() {
 105         return isutf8;
 106     }
 107 
 108     private Charset cs;
 109     private boolean isutf8;
 110     private ZipCoder utf8;
 111 
 112     private ZipCoder(Charset cs) {
 113         this.cs = cs;
 114         this.isutf8 = cs.name().equals("UTF-8");
 115     }
 116 
 117     static ZipCoder get(Charset charset) {
 118         return new ZipCoder(charset);
 119     }
 120 
 121     static ZipCoder get(String csn) {
 122         try {
 123             return new ZipCoder(Charset.forName(csn));
 124         } catch (Throwable t) {
 125             t.printStackTrace();
 126         }
 127         return new ZipCoder(Charset.defaultCharset());
 128     }
 129 
 130     private final ThreadLocal<CharsetDecoder> decTL = new ThreadLocal<>();
 131     private final ThreadLocal<CharsetEncoder> encTL = new ThreadLocal<>();
 132 
 133     private CharsetDecoder decoder() {
 134         CharsetDecoder dec = decTL.get();
 135         if (dec == null) {
 136             dec = cs.newDecoder()
 137               .onMalformedInput(CodingErrorAction.REPORT)
 138               .onUnmappableCharacter(CodingErrorAction.REPORT);
 139             decTL.set(dec);
 140         }
 141         return dec;
 142     }
 143 
 144     private CharsetEncoder encoder() {
 145         CharsetEncoder enc = encTL.get();
 146         if (enc == null) {
 147             enc = cs.newEncoder()
 148               .onMalformedInput(CodingErrorAction.REPORT)
 149               .onUnmappableCharacter(CodingErrorAction.REPORT);
 150             encTL.set(enc);
 151         }
 152         return enc;
 153     }
 154 }