1/* 2 * Copyright (c) 2015, 2016, 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 */ 25package jdk.internal.jimage.decompressor; 26 27import java.io.ByteArrayOutputStream; 28import java.util.zip.Inflater; 29 30/** 31 * 32 * ZIP Decompressor 33 * 34 * @implNote This class needs to maintain JDK 8 source compatibility. 35 * 36 * It is used internally in the JDK to implement jimage/jrtfs access, 37 * but also compiled and delivered as part of the jrtfs.jar to support access 38 * to the jimage file provided by the shipped JDK by tools running on JDK 8. 39 */ 40final class ZipDecompressor implements ResourceDecompressor { 41 42 @Override 43 public String getName() { 44 return ZipDecompressorFactory.NAME; 45 } 46 47 static byte[] decompress(byte[] bytesIn, int offset) throws Exception { 48 Inflater inflater = new Inflater(); 49 inflater.setInput(bytesIn, offset, bytesIn.length - offset); 50 ByteArrayOutputStream stream = new ByteArrayOutputStream(bytesIn.length - offset); 51 byte[] buffer = new byte[1024]; 52 53 while (!inflater.finished()) { 54 int count = inflater.inflate(buffer); 55 stream.write(buffer, 0, count); 56 } 57 58 stream.close(); 59 60 byte[] bytesOut = stream.toByteArray(); 61 inflater.end(); 62 63 return bytesOut; 64 } 65 66 @Override 67 public byte[] decompress(StringsProvider reader, byte[] content, int offset, 68 long originalSize) throws Exception { 69 byte[] decompressed = decompress(content, offset); 70 return decompressed; 71 } 72} 73