1 /*
   2  * Copyright (c) 2009, 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 java.util.zip;
  27 
  28 import java.nio.ByteBuffer;
  29 import java.nio.CharBuffer;
  30 import java.nio.charset.Charset;
  31 import java.nio.charset.StandardCharsets;
  32 import java.nio.charset.CharsetDecoder;
  33 import java.nio.charset.CharsetEncoder;
  34 import java.nio.charset.CoderResult;
  35 import java.nio.charset.CodingErrorAction;
  36 import java.util.Arrays;
  37 import sun.nio.cs.ArrayDecoder;
  38 import sun.nio.cs.ArrayEncoder;
  39 
  40 /**
  41  * Utility class for zipfile name and comment decoding and encoding
  42  */
  43 
  44 final class ZipCoder {
  45 
  46     String toString(byte[] ba, int length) {
  47         CharsetDecoder cd = decoder().reset();
  48         int len = (int)(length * cd.maxCharsPerByte());
  49         char[] ca = new char[len];
  50         if (len == 0)
  51             return new String(ca);
  52         // UTF-8 only for now. Other ArrayDeocder only handles
  53         // CodingErrorAction.REPLACE mode. ZipCoder uses
  54         // REPORT mode.
  55         if (isUTF8 && cd instanceof ArrayDecoder) {
  56             int clen = ((ArrayDecoder)cd).decode(ba, 0, length, ca);
  57             if (clen == -1)    // malformed
  58                 throw new IllegalArgumentException("MALFORMED");
  59             return new String(ca, 0, clen);
  60         }
  61         ByteBuffer bb = ByteBuffer.wrap(ba, 0, length);
  62         CharBuffer cb = CharBuffer.wrap(ca);
  63         CoderResult cr = cd.decode(bb, cb, true);
  64         if (!cr.isUnderflow())
  65             throw new IllegalArgumentException(cr.toString());
  66         cr = cd.flush(cb);
  67         if (!cr.isUnderflow())
  68             throw new IllegalArgumentException(cr.toString());
  69         return new String(ca, 0, cb.position());
  70     }
  71 
  72     String toString(byte[] ba) {
  73         return toString(ba, ba.length);
  74     }
  75 
  76     byte[] getBytes(String s) {
  77         CharsetEncoder ce = encoder().reset();
  78         char[] ca = s.toCharArray();
  79         int len = (int)(ca.length * ce.maxBytesPerChar());
  80         byte[] ba = new byte[len];
  81         if (len == 0)
  82             return ba;
  83         // UTF-8 only for now. Other ArrayDeocder only handles
  84         // CodingErrorAction.REPLACE mode.
  85         if (isUTF8 && ce instanceof ArrayEncoder) {
  86             int blen = ((ArrayEncoder)ce).encode(ca, 0, ca.length, ba);
  87             if (blen == -1)    // malformed
  88                 throw new IllegalArgumentException("MALFORMED");
  89             return Arrays.copyOf(ba, blen);
  90         }
  91         ByteBuffer bb = ByteBuffer.wrap(ba);
  92         CharBuffer cb = CharBuffer.wrap(ca);
  93         CoderResult cr = ce.encode(cb, bb, true);
  94         if (!cr.isUnderflow())
  95             throw new IllegalArgumentException(cr.toString());
  96         cr = ce.flush(bb);
  97         if (!cr.isUnderflow())
  98             throw new IllegalArgumentException(cr.toString());
  99         if (bb.position() == ba.length)  // defensive copy?
 100             return ba;
 101         else
 102             return Arrays.copyOf(ba, bb.position());
 103     }
 104 
 105     // assume invoked only if "this" is not utf8
 106     byte[] getBytesUTF8(String s) {
 107         if (isUTF8)
 108             return getBytes(s);
 109         if (utf8 == null)
 110             utf8 = new ZipCoder(StandardCharsets.UTF_8);
 111         return utf8.getBytes(s);
 112     }
 113 
 114 
 115     String toStringUTF8(byte[] ba, int len) {
 116         if (isUTF8)
 117             return toString(ba, len);
 118         if (utf8 == null)
 119             utf8 = new ZipCoder(StandardCharsets.UTF_8);
 120         return utf8.toString(ba, len);
 121     }
 122 
 123     boolean isUTF8() {
 124         return isUTF8;
 125     }
 126 
 127     private Charset cs;
 128     private CharsetDecoder dec;
 129     private CharsetEncoder enc;
 130     private boolean isUTF8;
 131     private ZipCoder utf8;
 132 
 133     private ZipCoder(Charset cs) {
 134         this.cs = cs;
 135         this.isUTF8 = cs.name().equals(StandardCharsets.UTF_8.name());
 136     }
 137 
 138     static ZipCoder get(Charset charset) {
 139         return new ZipCoder(charset);
 140     }
 141 
 142     private CharsetDecoder decoder() {
 143         if (dec == null) {
 144             dec = cs.newDecoder()
 145               .onMalformedInput(CodingErrorAction.REPORT)
 146               .onUnmappableCharacter(CodingErrorAction.REPORT);
 147         }
 148         return dec;
 149     }
 150 
 151     private CharsetEncoder encoder() {
 152         if (enc == null) {
 153             enc = cs.newEncoder()
 154               .onMalformedInput(CodingErrorAction.REPORT)
 155               .onUnmappableCharacter(CodingErrorAction.REPORT);
 156         }
 157         return enc;
 158     }
 159 }