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