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