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 */
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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 */
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