java.lang.module.ModuleReference#descriptor ( )源码实例Demo

/**
 * Creates a {@code Loader} in a loader pool that loads classes/resources
 * from one module.
 */
public Loader(ResolvedModule resolvedModule,
              LoaderPool pool,
              ClassLoader parent)
{
    super("Loader-" + resolvedModule.name(), parent);

    this.pool = pool;
    this.parent = parent;

    ModuleReference mref = resolvedModule.reference();
    ModuleDescriptor descriptor = mref.descriptor();
    String mn = descriptor.name();
    this.nameToModule = Map.of(mn, mref);

    Map<String, LoadedModule> localPackageToModule = new HashMap<>();
    LoadedModule lm = new LoadedModule(mref);
    descriptor.packages().forEach(pn -> localPackageToModule.put(pn, lm));
    this.localPackageToModule = localPackageToModule;

    this.acc = AccessController.getContext();
}
 

/**
 * Creates a {@code Loader} that loads classes/resources from a collection
 * of modules.
 *
 * @throws IllegalArgumentException
 *         If two or more modules have the same package
 */
public Loader(Collection<ResolvedModule> modules, ClassLoader parent) {
    super(parent);

    this.pool = null;
    this.parent = parent;

    Map<String, ModuleReference> nameToModule = new HashMap<>();
    Map<String, LoadedModule> localPackageToModule = new HashMap<>();
    for (ResolvedModule resolvedModule : modules) {
        ModuleReference mref = resolvedModule.reference();
        ModuleDescriptor descriptor = mref.descriptor();
        nameToModule.put(descriptor.name(), mref);
        descriptor.packages().forEach(pn -> {
            LoadedModule lm = new LoadedModule(mref);
            if (localPackageToModule.put(pn, lm) != null)
                throw new IllegalArgumentException("Package "
                    + pn + " in more than one module");
        });
    }
    this.nameToModule = nameToModule;
    this.localPackageToModule = localPackageToModule;

    this.acc = AccessController.getContext();
}
 

public Module toModule(ModuleReference mref) {
    try {
        String mn = mref.descriptor().name();
        URI location = mref.location().orElseThrow(FileNotFoundException::new);
        ModuleDescriptor md = mref.descriptor();
        Module.Builder builder = new Module.Builder(md, system.find(mn).isPresent());

        final ClassFileReader reader;
        if (location.getScheme().equals("jrt")) {
            reader = system.getClassReader(mn);
        } else {
            reader = ClassFileReader.newInstance(Paths.get(location), version);
        }

        builder.classes(reader);
        builder.location(location);

        return builder.build();
    } catch (IOException e) {
        throw new UncheckedIOException(e);
    }
}
 

/**
 * Creates a {@code Loader} in a loader pool that loads classes/resources
 * from one module.
 */
public Loader(ResolvedModule resolvedModule,
              LoaderPool pool,
              ClassLoader parent)
{
    super("Loader-" + resolvedModule.name(), parent);

    this.pool = pool;
    this.parent = parent;

    ModuleReference mref = resolvedModule.reference();
    ModuleDescriptor descriptor = mref.descriptor();
    String mn = descriptor.name();
    this.nameToModule = Map.of(mn, mref);

    Map<String, LoadedModule> localPackageToModule = new HashMap<>();
    LoadedModule lm = new LoadedModule(mref);
    descriptor.packages().forEach(pn -> localPackageToModule.put(pn, lm));
    this.localPackageToModule = localPackageToModule;

    this.acc = AccessController.getContext();
}
 

/**
 * Creates a {@code Loader} that loads classes/resources from a collection
 * of modules.
 *
 * @throws IllegalArgumentException
 *         If two or more modules have the same package
 */
public Loader(Collection<ResolvedModule> modules, ClassLoader parent) {
    super(parent);

    this.pool = null;
    this.parent = parent;

    Map<String, ModuleReference> nameToModule = new HashMap<>();
    Map<String, LoadedModule> localPackageToModule = new HashMap<>();
    for (ResolvedModule resolvedModule : modules) {
        ModuleReference mref = resolvedModule.reference();
        ModuleDescriptor descriptor = mref.descriptor();
        nameToModule.put(descriptor.name(), mref);
        descriptor.packages().forEach(pn -> {
            LoadedModule lm = new LoadedModule(mref);
            if (localPackageToModule.put(pn, lm) != null)
                throw new IllegalArgumentException("Package "
                    + pn + " in more than one module");
        });
    }
    this.nameToModule = nameToModule;
    this.localPackageToModule = localPackageToModule;

    this.acc = AccessController.getContext();
}
 

/**
 * Returns true if the given module opens the given package
 * unconditionally.
 *
 * @implNote This method currently iterates over each of the open
 * packages. This will be replaced once the ModuleDescriptor.Opens
 * API is updated.
 */
private boolean isOpen(ModuleReference mref, String pn) {
    ModuleDescriptor descriptor = mref.descriptor();
    if (descriptor.isOpen() || descriptor.isAutomatic())
        return true;
    for (ModuleDescriptor.Opens opens : descriptor.opens()) {
        String source = opens.source();
        if (!opens.isQualified() && source.equals(pn)) {
            return true;
        }
    }
    return false;
}
 

/**
 * Returns true if the given module opens the given package
 * unconditionally.
 *
 * @implNote This method currently iterates over each of the open
 * packages. This will be replaced once the ModuleDescriptor.Opens
 * API is updated.
 */
private boolean isOpen(ModuleReference mref, String pn) {
    ModuleDescriptor descriptor = mref.descriptor();
    if (descriptor.isOpen() || descriptor.isAutomatic())
        return true;
    for (ModuleDescriptor.Opens opens : descriptor.opens()) {
        String source = opens.source();
        if (!opens.isQualified() && source.equals(pn)) {
            return true;
        }
    }
    return false;
}
 

/**
 * Prints the module location and name.
 */
private void printModule(ModuleReference mref) {
    mref.location()
            .filter(uri -> !isJrt(uri))
            .ifPresent(uri -> out.print(uri + " "));
    ModuleDescriptor descriptor = mref.descriptor();
    out.print(descriptor.name());
    if (descriptor.isAutomatic())
        out.print(" automatic");
    out.println();
}
 

/**
 * Prints a single line with the module name, version and modifiers
 */
private static void showModule(ModuleReference mref) {
    ModuleDescriptor md = mref.descriptor();
    ostream.print(md.toNameAndVersion());
    mref.location()
            .filter(uri -> !isJrt(uri))
            .ifPresent(uri -> ostream.format(" %s", uri));
    if (md.isOpen())
        ostream.print(" open");
    if (md.isAutomatic())
        ostream.print(" automatic");
    ostream.println();
}
 

/**
 * Returns true if the given module opens the given package
 * unconditionally.
 *
 * @implNote This method currently iterates over each of the open
 * packages. This will be replaced once the ModuleDescriptor.Opens
 * API is updated.
 */
private boolean isOpen(ModuleReference mref, String pn) {
    ModuleDescriptor descriptor = mref.descriptor();
    if (descriptor.isOpen() || descriptor.isAutomatic())
        return true;
    for (ModuleDescriptor.Opens opens : descriptor.opens()) {
        String source = opens.source();
        if (!opens.isQualified() && source.equals(pn)) {
            return true;
        }
    }
    return false;
}
 

/**
 * Returns true if the given module opens the given package
 * unconditionally.
 *
 * @implNote This method currently iterates over each of the open
 * packages. This will be replaced once the ModuleDescriptor.Opens
 * API is updated.
 */
private boolean isOpen(ModuleReference mref, String pn) {
    ModuleDescriptor descriptor = mref.descriptor();
    if (descriptor.isOpen() || descriptor.isAutomatic())
        return true;
    for (ModuleDescriptor.Opens opens : descriptor.opens()) {
        String source = opens.source();
        if (!opens.isQualified() && source.equals(pn)) {
            return true;
        }
    }
    return false;
}
 

/**
 * Prints a single line with the module name, version and modifiers
 */
private static void showModule(ModuleReference mref) {
    ModuleDescriptor md = mref.descriptor();
    ostream.print(md.toNameAndVersion());
    mref.location()
            .filter(uri -> !isJrt(uri))
            .ifPresent(uri -> ostream.format(" %s", uri));
    if (md.isOpen())
        ostream.print(" open");
    if (md.isAutomatic())
        ostream.print(" automatic");
    ostream.println();
}
 

/**
 * Prints the module location and name.
 */
private void printModule(ModuleReference mref) {
    mref.location()
        .filter(uri -> !isJrt(uri))
        .ifPresent(uri -> ostream.print(uri + " "));
    ModuleDescriptor descriptor = mref.descriptor();
    ostream.print(descriptor.name());
    if (descriptor.isAutomatic())
        ostream.print(" automatic");
    ostream.println();
}
 

/**
 * Basic test of a multi-release JAR.
 */
public void testBasic() throws Exception {
    String name = "m1";

    ModuleDescriptor descriptor = ModuleDescriptor.newModule(name)
            .requires("java.base")
            .build();

    Path jar = new JarBuilder(name)
            .moduleInfo("module-info.class", descriptor)
            .resource("p/Main.class")
            .resource("p/Helper.class")
            .resource("META-INF/versions/" + VERSION + "/p/Helper.class")
            .resource("META-INF/versions/" + VERSION + "/p/internal/Helper.class")
            .build();

    // find the module
    ModuleFinder finder = ModuleFinder.of(jar);
    Optional<ModuleReference> omref = finder.find(name);
    assertTrue((omref.isPresent()));
    ModuleReference mref = omref.get();

    // check module packages
    descriptor = mref.descriptor();
    Set<String> packages = descriptor.packages();
    assertTrue(packages.contains("p"));
    if (MULTI_RELEASE) {
        assertTrue(packages.size() == 2);
        assertTrue(packages.contains("p.internal"));
    } else {
        assertTrue(packages.size() == 1);
    }
}
 

/**
 * Test a multi-release JAR with a module-info.class in the versioned
 * section of the JAR.
 */
public void testModuleInfoInVersionedSection() throws Exception {
    String name = "m1";

    ModuleDescriptor descriptor1 = ModuleDescriptor.newModule(name)
            .requires("java.base")
            .build();

    // module descriptor for versioned section
    ModuleDescriptor descriptor2 = ModuleDescriptor.newModule(name)
            .requires("java.base")
            .requires("jdk.unsupported")
            .build();

    Path jar = new JarBuilder(name)
            .moduleInfo(MODULE_INFO, descriptor1)
            .resource("p/Main.class")
            .resource("p/Helper.class")
            .moduleInfo("META-INF/versions/" + VERSION + "/" + MODULE_INFO, descriptor2)
            .resource("META-INF/versions/" + VERSION + "/p/Helper.class")
            .resource("META-INF/versions/" + VERSION + "/p/internal/Helper.class")
            .build();

    // find the module
    ModuleFinder finder = ModuleFinder.of(jar);
    Optional<ModuleReference> omref = finder.find(name);
    assertTrue((omref.isPresent()));
    ModuleReference mref = omref.get();

    // ensure that the right module-info.class is loaded
    ModuleDescriptor descriptor = mref.descriptor();
    assertEquals(descriptor.name(), name);
    if (MULTI_RELEASE) {
        assertEquals(descriptor.requires(), descriptor2.requires());
    } else {
        assertEquals(descriptor.requires(), descriptor1.requires());
    }
}
 

/**
 * Test multi-release JAR as an automatic module.
 */
public void testAutomaticModule() throws Exception {
    String name = "m";

    Path jar = new JarBuilder(name)
            .resource("p/Main.class")
            .resource("p/Helper.class")
            .resource("META-INF/versions/" + VERSION + "/p/Helper.class")
            .resource("META-INF/versions/" + VERSION + "/p/internal/Helper.class")
            .build();

    // find the module
    ModuleFinder finder = ModuleFinder.of(jar);
    Optional<ModuleReference> omref = finder.find(name);
    assertTrue((omref.isPresent()));
    ModuleReference mref = omref.get();

    // check module packages
    ModuleDescriptor descriptor = mref.descriptor();
    Set<String> packages = descriptor.packages();
    if (MULTI_RELEASE) {
        assertTrue(packages.size() == 2);
        assertTrue(packages.contains("p.internal"));
    } else {
        assertTrue(packages.size() == 1);
    }
}
 

/**
 * Test JAR files with the Automatic-Module-Name attribute
 */
@Test(dataProvider = "modulenames")
public void testAutomaticModuleNameAttribute(String name, String vs)
    throws IOException
{
    Manifest man = new Manifest();
    Attributes attrs = man.getMainAttributes();
    attrs.put(Attributes.Name.MANIFEST_VERSION, "1.0.0");
    attrs.put(new Attributes.Name("Automatic-Module-Name"), name);

    Path dir = Files.createTempDirectory(USER_DIR, "mods");
    String jar;
    if (vs == null) {
        jar = "m.jar";
    } else {
        jar = "m-" + vs + ".jar";
    }
    createDummyJarFile(dir.resolve(jar), man);

    ModuleFinder finder = ModuleFinder.of(dir);

    assertTrue(finder.findAll().size() == 1);
    assertTrue(finder.find(name).isPresent());

    ModuleReference mref = finder.find(name).get();
    ModuleDescriptor descriptor = mref.descriptor();
    assertEquals(descriptor.name(), name);
    assertEquals(descriptor.version()
            .map(ModuleDescriptor.Version::toString)
            .orElse(null), vs);
}
 

private static void checkArtifactModuleName(Log log, String moduleName, ModuleReference moduleReference, ArtifactDescriptor resolvedArtifact) {
  var descriptor = moduleReference.descriptor();
  if (descriptor.isAutomatic()) {
    return;
  }
  var artifactModuleName = descriptor.name();
  if (!artifactModuleName.equals(moduleName)) {
    log.info(null, __ -> "WARNING! artifact module name " + artifactModuleName + " (" + resolvedArtifact + ") declared in the module-info is different from declared module name " + moduleName);
  }
}
 

ModuleSummary(ModuleReference mref, Path jmod) throws IOException {
    this.name = mref.descriptor().name();
    this.descriptor = mref.descriptor();
    this.jmodInfo = new JmodInfo(jmod);
}
 

private static void rewrite(ModuleReference rootModule, LinkedHashSet<String> dependencies, LinkedHashSet<String> requires, Set<String> packages, ModuleFinder finder, Path destination) throws IOException {
  // create a map old package name -> new package name
  var rootModuleName = rootModule.descriptor().name();
  var internalRootModuleName = rootModuleName.replace('.', '/');
  var internalPackageNameMap = packages.stream()
      .map(name -> name.replace('.', '/'))
      .collect(toUnmodifiableMap(name -> name, name -> internalRootModuleName + '/' + name));
  //System.out.println(internalPackageNameMap);
  
  var newPackages = new HashSet<String>();
  
  Path path = destination.resolve(rootModuleName + ".jar");
  Files.createDirectories(path.getParent());
  try(var output = Files.newOutputStream(path);
      var outputStream = new JarOutputStream(output)) {
    
    // rewrite all the classes of the dependencies
    var entryNames = new HashSet<>();
    for(var dependency: dependencies) {
      var reference = finder.find(dependency).orElseThrow();
      try(var reader = reference.open()) {
        for(String filename: (Iterable<String>)reader.list()::iterator) {
          //System.out.println("filename " + filename);
          
          if (filename.equals("module-info.class") ||  // skip module-info
              filename.endsWith("/") ||                // skip all directories
              filename.startsWith("META-INF")) {       // skip META-INF
            continue;
          }
          
          if (!entryNames.add(filename)) {
            System.out.println("duplicate entry " + filename + " skip it !");
            continue;
          }
          
          try(var inputStream = reader.open(filename).orElseThrow(() -> new IOException("can not read " + filename))) {
            if (!filename.endsWith(".class")) {  // only rewrite .class
                                                 // otherwise copy the resources
              
              getPackage(filename).ifPresent(newPackages::add);
              
              outputStream.putNextEntry(new JarEntry(filename));
              inputStream.transferTo(outputStream);
              continue;
            }
          
            var newFilename = interpolateInternalName(internalPackageNameMap, filename);
            getPackage(newFilename).ifPresent(newPackages::add);
            outputStream.putNextEntry(new JarEntry(newFilename));
            outputStream.write(rewriteBytecode(internalPackageNameMap, inputStream.readAllBytes()));
          }
        }
      }
    }
    
    // then insert the new module-info and interpolate it
    outputStream.putNextEntry(new JarEntry("module-info.class"));
    
    var builder = ModuleDescriptor.newOpenModule(rootModuleName);
    var rootModuleDescriptor = rootModule.descriptor();
    
    rootModuleDescriptor.version().ifPresent(builder::version);
    requires.forEach(builder::requires);
    rootModuleDescriptor.exports().forEach(builder::exports);
    rootModuleDescriptor.opens().forEach(builder::opens);
    builder.packages(rootModuleDescriptor.packages());
    
    dependencies.stream()
      .flatMap(name -> finder.find(name).stream())
      .map(ModuleReference::descriptor)
      .forEach(descriptor -> {
        descriptor.provides().forEach(provides -> {
          builder.provides(
              interpolateClassName(internalPackageNameMap, provides.service()),
              provides.providers().stream().map(provider -> interpolateClassName(internalPackageNameMap, provider)).collect(toUnmodifiableList())
              );
        });
        descriptor.uses().forEach(uses -> builder.uses(interpolateClassName(internalPackageNameMap, uses)));
      });
    builder.packages(newPackages);
    var moduleDescriptor = builder.build();
    
    outputStream.write(ModuleHelper.moduleDescriptorToBinary(moduleDescriptor));
  }
}