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 }