1 /*
   2  * Copyright (c) 2015, 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 package jdk.internal.jimage.decompressor;
  26 
  27 import java.io.ByteArrayOutputStream;
  28 import java.io.IOException;
  29 import java.util.zip.DataFormatException;
  30 import java.util.zip.Inflater;
  31 
  32 /**
  33  *
  34  * ZIP Decompressor
  35  */
  36 final class ZipDecompressor implements ResourceDecompressor {
  37 
  38     @Override
  39     public String getName() {
  40         return ZipDecompressorFactory.NAME;
  41     }
  42 
  43     static byte[] decompress(byte[] bytesIn, int offset) {
  44         Inflater inflater = new Inflater();
  45         inflater.setInput(bytesIn, offset, bytesIn.length - offset);
  46         ByteArrayOutputStream stream = new ByteArrayOutputStream(bytesIn.length - offset);
  47         byte[] buffer = new byte[1024];
  48 
  49         while (!inflater.finished()) {
  50             int count;
  51 
  52             try {
  53                 count = inflater.inflate(buffer);
  54             } catch (DataFormatException ex) {
  55                 return null;
  56             }
  57 
  58             stream.write(buffer, 0, count);
  59         }
  60 
  61         try {
  62             stream.close();
  63         } catch (IOException ex) {
  64             return null;
  65         }
  66 
  67         byte[] bytesOut = stream.toByteArray();
  68         inflater.end();
  69 
  70         return bytesOut;
  71     }
  72 
  73     @Override
  74     public byte[] decompress(StringsProvider reader, byte[] content, int offset,
  75             int originalSize) throws Exception {
  76         byte[] decompressed = decompress(content, offset);
  77         return decompressed;
  78     }
  79 }