1/* 2 * Copyright (c) 2015, 2017, 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 26package jdk.nio.zipfs; 27 28import java.io.IOException; 29import java.io.InputStream; 30import java.lang.Runtime.Version; 31import java.nio.file.NoSuchFileException; 32import java.nio.file.Path; 33import java.util.Arrays; 34import java.util.HashMap; 35import java.util.Map; 36import java.util.TreeMap; 37import java.util.function.Consumer; 38import java.util.function.Function; 39import java.util.jar.Attributes; 40import java.util.jar.Manifest; 41 42/** 43 * Adds aliasing to ZipFileSystem to support multi-release jar files. An alias map 44 * is created by {@link JarFileSystem#createVersionedLinks(int)}. The map is then 45 * consulted when an entry is looked up in {@link JarFileSystem#getEntry(byte[])} 46 * to determine if the entry has a corresponding versioned entry. If so, the 47 * versioned entry is returned. 48 * 49 * @author Steve Drach 50 */ 51 52class JarFileSystem extends ZipFileSystem { 53 private Function<byte[],byte[]> lookup; 54 55 @Override 56 IndexNode getInode(byte[] path) { 57 // check for an alias to a versioned entry 58 byte[] versionedPath = lookup.apply(path); 59 return versionedPath == null ? super.getInode(path) : super.getInode(versionedPath); 60 } 61 62 JarFileSystem(ZipFileSystemProvider provider, Path zfpath, Map<String,?> env) 63 throws IOException { 64 super(provider, zfpath, env); 65 lookup = path -> path; // lookup needs to be set before isMultiReleaseJar is called 66 // because it eventually calls getEntry 67 if (isMultiReleaseJar()) { 68 int version; 69 Object o = env.get("multi-release"); 70 if (o instanceof String) { 71 String s = (String)o; 72 if (s.equals("runtime")) { 73 version = Runtime.version().major(); 74 } else { 75 version = Integer.parseInt(s); 76 } 77 } else if (o instanceof Integer) { 78 version = (Integer)o; 79 } else if (o instanceof Version) { 80 version = ((Version)o).major(); 81 } else { 82 throw new IllegalArgumentException("env parameter must be String, Integer, " 83 + "or Version"); 84 } 85 lookup = createVersionedLinks(version < 0 ? 0 : version); 86 setReadOnly(); 87 } 88 } 89 90 private boolean isMultiReleaseJar() throws IOException { 91 try (InputStream is = newInputStream(getBytes("/META-INF/MANIFEST.MF"))) { 92 String multiRelease = new Manifest(is).getMainAttributes() 93 .getValue(Attributes.Name.MULTI_RELEASE); 94 return "true".equalsIgnoreCase(multiRelease); 95 } catch (NoSuchFileException x) { 96 return false; 97 } 98 } 99 100 /** 101 * create a map of aliases for versioned entries, for example: 102 * version/PackagePrivate.class -> META-INF/versions/9/version/PackagePrivate.class 103 * version/PackagePrivate.java -> META-INF/versions/9/version/PackagePrivate.java 104 * version/Version.class -> META-INF/versions/10/version/Version.class 105 * version/Version.java -> META-INF/versions/10/version/Version.java 106 * 107 * then wrap the map in a function that getEntry can use to override root 108 * entry lookup for entries that have corresponding versioned entries 109 */ 110 private Function<byte[],byte[]> createVersionedLinks(int version) { 111 HashMap<IndexNode,byte[]> aliasMap = new HashMap<>(); 112 getVersionMap(version, getInode(getBytes("/META-INF/versions"))).values() 113 .forEach(versionNode -> { // for each META-INF/versions/{n} directory 114 // put all the leaf inodes, i.e. entries, into the alias map 115 // possibly shadowing lower versioned entries 116 walk(versionNode, entryNode -> { 117 byte[] rootName = getRootName(versionNode, entryNode); 118 if (rootName != null) { 119 IndexNode rootNode = getInode(rootName); 120 if (rootNode == null) { // no matching root node, make a virtual one 121 rootNode = IndexNode.keyOf(rootName); 122 } 123 aliasMap.put(rootNode, entryNode.name); 124 } 125 }); 126 }); 127 return path -> aliasMap.get(IndexNode.keyOf(path)); 128 } 129 130 /** 131 * create a sorted version map of version -> inode, for inodes <= max version 132 * 9 -> META-INF/versions/9 133 * 10 -> META-INF/versions/10 134 */ 135 private TreeMap<Integer, IndexNode> getVersionMap(int version, IndexNode metaInfVersions) { 136 TreeMap<Integer,IndexNode> map = new TreeMap<>(); 137 IndexNode child = metaInfVersions.child; 138 while (child != null) { 139 Integer key = getVersion(child.name, metaInfVersions.name.length + 1); 140 if (key != null && key <= version) { 141 map.put(key, child); 142 } 143 child = child.sibling; 144 } 145 return map; 146 } 147 148 /** 149 * extract the integer version number -- META-INF/versions/9 returns 9 150 */ 151 private Integer getVersion(byte[] name, int offset) { 152 try { 153 return Integer.parseInt(getString(Arrays.copyOfRange(name, offset, name.length))); 154 } catch (NumberFormatException x) { 155 // ignore this even though it might indicate issues with the JAR structure 156 return null; 157 } 158 } 159 160 /** 161 * walk the IndexNode tree processing all leaf nodes 162 */ 163 private void walk(IndexNode inode, Consumer<IndexNode> process) { 164 if (inode == null) return; 165 if (inode.isDir()) { 166 walk(inode.child, process); 167 } else { 168 process.accept(inode); 169 } 170 walk(inode.sibling, process); 171 } 172 173 /** 174 * extract the root name from a versioned entry name 175 * given inode for META-INF/versions/9/foo/bar.class 176 * and prefix META-INF/versions/9/ 177 * returns foo/bar.class 178 */ 179 private byte[] getRootName(IndexNode prefix, IndexNode inode) { 180 int offset = prefix.name.length; 181 byte[] fullName = inode.name; 182 return Arrays.copyOfRange(fullName, offset, fullName.length); 183 } 184} 185