1 /* 2 * Copyright (c) 2015, 2019, 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.io.IOException; 29 import java.io.InputStream; 30 import java.lang.Runtime.Version; 31 import java.nio.file.NoSuchFileException; 32 import java.nio.file.Path; 33 import java.util.Arrays; 34 import java.util.HashMap; 35 import java.util.Map; 36 import java.util.TreeMap; 37 import java.util.function.Consumer; 38 import java.util.function.Function; 39 import java.util.jar.Attributes; 40 import 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#getInode(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 class JarFileSystem extends ZipFileSystem { 52 // lookup needs to be initialized because isMultiReleaseJar is called before createVersionedLinks 53 private Function<byte[], byte[]> lookup = path -> path; 54 55 @Override 56 IndexNode getInode(byte[] path) { 57 // check for an alias to a versioned entry 58 return super.getInode(lookup.apply(path)); 59 } 60 61 JarFileSystem(ZipFileSystemProvider provider, Path zfpath, Map<String,?> env) throws IOException { 62 super(provider, zfpath, env); 63 if (isMultiReleaseJar()) { 64 int version; 65 Object o = env.get("multi-release"); 66 if (o instanceof String) { 67 String s = (String)o; 68 if (s.equals("runtime")) { 69 version = Runtime.version().feature(); 70 } else { 71 version = Integer.parseInt(s); 72 } 73 } else if (o instanceof Integer) { 74 version = (Integer)o; 75 } else if (o instanceof Version) { 76 version = ((Version)o).feature(); 77 } else { 78 throw new IllegalArgumentException("env parameter must be String, Integer, " 79 + "or Version"); 80 } 81 createVersionedLinks(version < 0 ? 0 : version); 82 setReadOnly(); 83 } 84 } 85 86 private boolean isMultiReleaseJar() throws IOException { 87 try (InputStream is = newInputStream(getBytes("/META-INF/MANIFEST.MF"))) { 88 String multiRelease = new Manifest(is).getMainAttributes() 89 .getValue(Attributes.Name.MULTI_RELEASE); 90 return "true".equalsIgnoreCase(multiRelease); 91 } catch (NoSuchFileException x) { 92 return false; 93 } 94 } 95 96 /** 97 * create a map of aliases for versioned entries, for example: 98 * version/PackagePrivate.class -> META-INF/versions/9/version/PackagePrivate.class 99 * version/PackagePrivate.java -> META-INF/versions/9/version/PackagePrivate.java 100 * version/Version.class -> META-INF/versions/10/version/Version.class 101 * version/Version.java -> META-INF/versions/10/version/Version.java 102 * 103 * then wrap the map in a function that getEntry can use to override root 104 * entry lookup for entries that have corresponding versioned entries 105 */ 106 private void createVersionedLinks(int version) { 107 IndexNode verdir = getInode(getBytes("/META-INF/versions")); 108 // nothing to do, if no /META-INF/versions 109 if (verdir == null) { 110 return; 111 } 112 // otherwise, create a map and for each META-INF/versions/{n} directory 113 // put all the leaf inodes, i.e. entries, into the alias map 114 // possibly shadowing lower versioned entries 115 HashMap<IndexNode, byte[]> aliasMap = new HashMap<>(); 116 getVersionMap(version, verdir).values().forEach(versionNode -> 117 walk(versionNode.child, entryNode -> 118 aliasMap.put( 119 getOrCreateInode(getRootName(entryNode, versionNode), entryNode.isdir), 120 entryNode.name)) 121 ); 122 lookup = path -> { 123 byte[] entry = aliasMap.get(IndexNode.keyOf(path)); 124 return entry == null ? path : entry; 125 }; 126 } 127 128 /** 129 * create a sorted version map of version -> inode, for inodes <= max version 130 * 9 -> META-INF/versions/9 131 * 10 -> META-INF/versions/10 132 */ 133 private TreeMap<Integer, IndexNode> getVersionMap(int version, IndexNode metaInfVersions) { 134 TreeMap<Integer,IndexNode> map = new TreeMap<>(); 135 IndexNode child = metaInfVersions.child; 136 while (child != null) { 137 Integer key = getVersion(child, metaInfVersions); 138 if (key != null && key <= version) { 139 map.put(key, child); 140 } 141 child = child.sibling; 142 } 143 return map; 144 } 145 146 /** 147 * extract the integer version number -- META-INF/versions/9 returns 9 148 */ 149 private Integer getVersion(IndexNode inode, IndexNode metaInfVersions) { 150 try { 151 byte[] fullName = inode.name; 152 return Integer.parseInt(getString(Arrays 153 .copyOfRange(fullName, metaInfVersions.name.length + 1, fullName.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> consumer) { 164 if (inode == null) return; 165 if (inode.isDir()) { 166 walk(inode.child, consumer); 167 } else { 168 consumer.accept(inode); 169 } 170 walk(inode.sibling, consumer); 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 inode, IndexNode prefix) { 180 byte[] fullName = inode.name; 181 return Arrays.copyOfRange(fullName, prefix.name.length, fullName.length); 182 } 183 }