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 Object o = getRuntimeVersion(env);
64 if (isMultiReleaseJar() && (o != null)) {
65 int version;
66 if (o instanceof String) {
67 String s = (String)o;
68 if (s.equals("runtime")) {
69 version = Runtime.version().feature();
70 } else if (s.matches("^[1-9][0-9]*$")) {
71 version = Version.parse(s).feature();
72 } else {
73 throw new IllegalArgumentException("Invalid runtime version");
74 }
75 } else if (o instanceof Integer) {
76 version = Version.parse(((Integer)o).toString()).feature();
77 } else if (o instanceof Version) {
78 version = ((Version)o).feature();
79 } else {
80 throw new IllegalArgumentException("env parameter must be String, Integer, "
81 + "or Version");
82 }
83 createVersionedLinks(version < 0 ? 0 : version);
84 setReadOnly();
85 }
86 }
87
88 /**
89 * Utility method to get the release version for a multi-release JAR. It
90 * first checks the documented property {@code releaseVersion} and if not
91 * found checks the original property {@code multi-release}
92 * @param env ZIP FS map
93 * @return release version or null if it is not specified
94 */
95 private Object getRuntimeVersion(Map<String, ?> env) {
96 Object o = null;
97 if (env.containsKey(ZipFileSystemProvider.PROPERTY_RELEASE_VERSION)) {
98 o = env.get(ZipFileSystemProvider.PROPERTY_RELEASE_VERSION);
99 } else {
100 o = env.get(ZipFileSystemProvider.PROPERTY_MULTI_RELEASE);
101 }
102 return o;
103 }
104
105 private boolean isMultiReleaseJar() throws IOException {
106 try (InputStream is = newInputStream(getBytes("/META-INF/MANIFEST.MF"))) {
107 String multiRelease = new Manifest(is).getMainAttributes()
108 .getValue(Attributes.Name.MULTI_RELEASE);
109 return "true".equalsIgnoreCase(multiRelease);
110 } catch (NoSuchFileException x) {
111 return false;
112 }
113 }
114
115 /**
116 * create a map of aliases for versioned entries, for example:
117 * version/PackagePrivate.class -> META-INF/versions/9/version/PackagePrivate.class
118 * version/PackagePrivate.java -> META-INF/versions/9/version/PackagePrivate.java
119 * version/Version.class -> META-INF/versions/10/version/Version.class
120 * version/Version.java -> META-INF/versions/10/version/Version.java
121 *
122 * then wrap the map in a function that getEntry can use to override root
123 * entry lookup for entries that have corresponding versioned entries
124 */
125 private void createVersionedLinks(int version) {
126 IndexNode verdir = getInode(getBytes("/META-INF/versions"));
127 // nothing to do, if no /META-INF/versions
128 if (verdir == null) {
129 return;
130 }
131 // otherwise, create a map and for each META-INF/versions/{n} directory
132 // put all the leaf inodes, i.e. entries, into the alias map
133 // possibly shadowing lower versioned entries
134 HashMap<IndexNode, byte[]> aliasMap = new HashMap<>();
135 getVersionMap(version, verdir).values().forEach(versionNode ->
136 walk(versionNode.child, entryNode ->
137 aliasMap.put(
138 getOrCreateInode(getRootName(entryNode, versionNode), entryNode.isdir),
139 entryNode.name))
140 );
141 lookup = path -> {
142 byte[] entry = aliasMap.get(IndexNode.keyOf(path));
143 return entry == null ? path : entry;
144 };
145 }
146
147 /**
148 * create a sorted version map of version -> inode, for inodes <= max version
149 * 9 -> META-INF/versions/9
150 * 10 -> META-INF/versions/10
151 */
152 private TreeMap<Integer, IndexNode> getVersionMap(int version, IndexNode metaInfVersions) {
153 TreeMap<Integer,IndexNode> map = new TreeMap<>();
154 IndexNode child = metaInfVersions.child;
155 while (child != null) {
156 Integer key = getVersion(child, metaInfVersions);
157 if (key != null && key <= version) {
158 map.put(key, child);
159 }
160 child = child.sibling;
161 }
162 return map;
163 }
164
165 /**
166 * extract the integer version number -- META-INF/versions/9 returns 9
167 */
168 private Integer getVersion(IndexNode inode, IndexNode metaInfVersions) {
169 try {
170 byte[] fullName = inode.name;
171 return Integer.parseInt(getString(Arrays
172 .copyOfRange(fullName, metaInfVersions.name.length + 1, fullName.length)));
173 } catch (NumberFormatException x) {
174 // ignore this even though it might indicate issues with the JAR structure
175 return null;
176 }
177 }
178
179 /**
180 * walk the IndexNode tree processing all leaf nodes
181 */
182 private void walk(IndexNode inode, Consumer<IndexNode> consumer) {
183 if (inode == null) return;
184 if (inode.isDir()) {
185 walk(inode.child, consumer);
186 } else {
187 consumer.accept(inode);
188 }
189 walk(inode.sibling, consumer);
190 }
191
192 /**
193 * extract the root name from a versioned entry name
194 * given inode for META-INF/versions/9/foo/bar.class
195 * and prefix META-INF/versions/9/
196 * returns foo/bar.class
197 */
198 private byte[] getRootName(IndexNode inode, IndexNode prefix) {
199 byte[] fullName = inode.name;
200 return Arrays.copyOfRange(fullName, prefix.name.length, fullName.length);
201 }
202 }