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/*
 * Copyright 2014 - Present Rafael Winterhalter
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package net.bytebuddy.dynamic.loading;

import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
import net.bytebuddy.ClassFileVersion;
import net.bytebuddy.build.AccessControllerPlugin;
import net.bytebuddy.build.HashCodeAndEqualsPlugin;
import net.bytebuddy.description.type.TypeDescription;
import net.bytebuddy.utility.GraalImageCode;
import net.bytebuddy.utility.JavaModule;
import net.bytebuddy.utility.dispatcher.JavaDispatcher;
import net.bytebuddy.utility.nullability.AlwaysNull;
import net.bytebuddy.utility.nullability.MaybeNull;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.*;
import java.security.PrivilegedAction;
import java.security.ProtectionDomain;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;

/**
 * 

* A {@link java.lang.ClassLoader} that is capable of loading explicitly defined classes. The class loader will free * any binary resources once a class that is defined by its binary data is loaded. This class loader is thread safe since * the class loading mechanics are only called from synchronized context. *

*

* Note: Instances of this class loader return URLs for their represented class loaders with the bytebuddy schema. * These URLs do not represent URIs as two classes with the same name yield identical URLs but might represents different byte * arrays. *

*

* Note: Any class and package definition is performed using the creator's {@code java.security.AccessControlContext}. *

*/ public class ByteArrayClassLoader extends InjectionClassLoader { /** * The schema for URLs that represent a class file of byte array class loaders. */ public static final String URL_SCHEMA = "bytebuddy"; /** * Indicates that an array should be included from its first index. Improves the source code readability. */ private static final int FROM_BEGINNING = 0; /** * Indicates that a URL does not exist to improve code readability. */ @AlwaysNull private static final URL NO_URL = null; /** * A strategy for locating a package by name. */ private static final PackageLookupStrategy PACKAGE_LOOKUP_STRATEGY = doPrivileged(PackageLookupStrategy.CreationAction.INSTANCE); /** * The synchronization engine for the executing JVM. */ protected static final SynchronizationStrategy.Initializable SYNCHRONIZATION_STRATEGY = doPrivileged(SynchronizationStrategy.CreationAction.INSTANCE); /* * Register class loader as parallel capable if the current VM supports it. */ static { doRegisterAsParallelCapable(); } /** * Registers class loader as parallel capable if possible. */ @SuppressFBWarnings(value = "DP_DO_INSIDE_DO_PRIVILEGED", justification = "Must be invoked from targeting class loader type.") private static void doRegisterAsParallelCapable() { try { Method method = ClassLoader.class.getDeclaredMethod("registerAsParallelCapable"); method.setAccessible(true); method.invoke(null); } catch (Throwable ignored) { /* do nothing */ } } /** * A proxy for {@code java.security.AccessController#doPrivileged} that is activated if available. * * @param action The action to execute from a privileged context. * @param The type of the action's resolved value. * @return The action's resolved value. */ @AccessControllerPlugin.Enhance private static T doPrivileged(PrivilegedAction action) { return action.run(); } /** * A mutable map of type names mapped to their binary representation. */ protected final ConcurrentMap typeDefinitions; /** * The persistence handler of this class loader. */ protected final PersistenceHandler persistenceHandler; /** * The protection domain to apply. Might be {@code null} when referencing the default protection domain. */ @MaybeNull protected final ProtectionDomain protectionDomain; /** * The package definer to be queried for package definitions. */ protected final PackageDefinitionStrategy packageDefinitionStrategy; /** * The class file transformer to apply on loaded classes. */ protected final ClassFilePostProcessor classFilePostProcessor; /** * The access control context to use for loading classes or {@code null} if this is not supported on the current VM. */ @MaybeNull protected final Object accessControlContext; /** * Creates a new class loader for a given definition of classes. * * @param parent The {@link java.lang.ClassLoader} that is the parent of this class loader. * @param typeDefinitions A map of fully qualified class names pointing to their binary representations. */ public ByteArrayClassLoader(@MaybeNull ClassLoader parent, Map typeDefinitions) { this(parent, true, typeDefinitions); } /** * Creates a new class loader for a given definition of classes. * * @param parent The {@link java.lang.ClassLoader} that is the parent of this class loader. * @param sealed {@code true} if this class loader is sealed. * @param typeDefinitions A map of fully qualified class names pointing to their binary representations. */ public ByteArrayClassLoader(@MaybeNull ClassLoader parent, boolean sealed, Map typeDefinitions) { this(parent, sealed, typeDefinitions, PersistenceHandler.LATENT); } /** * Creates a new class loader for a given definition of classes. * * @param parent The {@link java.lang.ClassLoader} that is the parent of this class loader. * @param typeDefinitions A map of fully qualified class names pointing to their binary representations. * @param persistenceHandler The persistence handler of this class loader. */ public ByteArrayClassLoader(@MaybeNull ClassLoader parent, Map typeDefinitions, PersistenceHandler persistenceHandler) { this(parent, true, typeDefinitions, persistenceHandler); } /** * Creates a new class loader for a given definition of classes. * * @param parent The {@link java.lang.ClassLoader} that is the parent of this class loader. * @param sealed {@code true} if this class loader is sealed. * @param typeDefinitions A map of fully qualified class names pointing to their binary representations. * @param persistenceHandler The persistence handler of this class loader. */ public ByteArrayClassLoader(@MaybeNull ClassLoader parent, boolean sealed, Map typeDefinitions, PersistenceHandler persistenceHandler) { this(parent, sealed, typeDefinitions, ClassLoadingStrategy.NO_PROTECTION_DOMAIN, persistenceHandler, PackageDefinitionStrategy.Trivial.INSTANCE); } /** * Creates a new class loader for a given definition of classes. * * @param parent The {@link java.lang.ClassLoader} that is the parent of this class loader. * @param typeDefinitions A map of fully qualified class names pointing to their binary representations. * @param protectionDomain The protection domain to apply where {@code null} references an implicit protection domain. * @param packageDefinitionStrategy The package definer to be queried for package definitions. * @param persistenceHandler The persistence handler of this class loader. */ public ByteArrayClassLoader(@MaybeNull ClassLoader parent, Map typeDefinitions, @MaybeNull ProtectionDomain protectionDomain, PersistenceHandler persistenceHandler, PackageDefinitionStrategy packageDefinitionStrategy) { this(parent, true, typeDefinitions, protectionDomain, persistenceHandler, packageDefinitionStrategy); } /** * Creates a new class loader for a given definition of classes. * * @param parent The {@link java.lang.ClassLoader} that is the parent of this class loader. * @param sealed {@code true} if this class loader is sealed. * @param typeDefinitions A map of fully qualified class names pointing to their binary representations. * @param protectionDomain The protection domain to apply where {@code null} references an implicit protection domain. * @param packageDefinitionStrategy The package definer to be queried for package definitions. * @param persistenceHandler The persistence handler of this class loader. */ public ByteArrayClassLoader(@MaybeNull ClassLoader parent, boolean sealed, Map typeDefinitions, @MaybeNull ProtectionDomain protectionDomain, PersistenceHandler persistenceHandler, PackageDefinitionStrategy packageDefinitionStrategy) { this(parent, sealed, typeDefinitions, protectionDomain, persistenceHandler, packageDefinitionStrategy, ClassFilePostProcessor.NoOp.INSTANCE); } /** * Creates a new class loader for a given definition of classes. * * @param parent The {@link java.lang.ClassLoader} that is the parent of this class loader. * @param typeDefinitions A map of fully qualified class names pointing to their binary representations. * @param protectionDomain The protection domain to apply where {@code null} references an implicit protection domain. * @param packageDefinitionStrategy The package definer to be queried for package definitions. * @param persistenceHandler The persistence handler of this class loader. * @param classFilePostProcessor A post processor for class files to apply p */ public ByteArrayClassLoader(@MaybeNull ClassLoader parent, Map typeDefinitions, @MaybeNull ProtectionDomain protectionDomain, PersistenceHandler persistenceHandler, PackageDefinitionStrategy packageDefinitionStrategy, ClassFilePostProcessor classFilePostProcessor) { this(parent, true, typeDefinitions, protectionDomain, persistenceHandler, packageDefinitionStrategy, classFilePostProcessor); } /** * Creates a new class loader for a given definition of classes. * * @param parent The {@link java.lang.ClassLoader} that is the parent of this class loader. * @param sealed {@code true} if this class loader is sealed. * @param typeDefinitions A map of fully qualified class names pointing to their binary representations. * @param protectionDomain The protection domain to apply where {@code null} references an implicit protection domain. * @param packageDefinitionStrategy The package definer to be queried for package definitions. * @param persistenceHandler The persistence handler of this class loader. * @param classFilePostProcessor A post processor for class files to apply p */ public ByteArrayClassLoader(@MaybeNull ClassLoader parent, boolean sealed, Map typeDefinitions, @MaybeNull ProtectionDomain protectionDomain, PersistenceHandler persistenceHandler, PackageDefinitionStrategy packageDefinitionStrategy, ClassFilePostProcessor classFilePostProcessor) { super(parent, sealed); this.typeDefinitions = new ConcurrentHashMap(typeDefinitions); this.protectionDomain = protectionDomain; this.persistenceHandler = persistenceHandler; this.packageDefinitionStrategy = packageDefinitionStrategy; this.classFilePostProcessor = classFilePostProcessor; accessControlContext = getContext(); } /** * A proxy for {@code java.security.AccessController#getContext} that is activated if available. * * @return The current access control context or {@code null} if the current VM does not support it. */ @MaybeNull @AccessControllerPlugin.Enhance private static Object getContext() { return null; } /** * A proxy for {@code java.security.AccessController#doPrivileged} that is activated if available. * * @param action The action to execute from a privileged context. * @param context The access control context or {@code null} if the current VM does not support it. * @param The type of the action's resolved value. * @return The action's resolved value. */ @AccessControllerPlugin.Enhance private static T doPrivileged(PrivilegedAction action, @MaybeNull @SuppressWarnings("unused") Object context) { return action.run(); } /** * Resolves a method handle in the scope of the {@link ByteArrayClassLoader} class. * * @return A method handle for this class. * @throws Exception If the method handle facility is not supported by the current virtual machine. */ private static Object methodHandle() throws Exception { return Class.forName("java.lang.invoke.MethodHandles").getMethod("lookup").invoke(null); } /** * Loads a given set of class descriptions and their binary representations. * * @param classLoader The parent class loader. * @param types The unloaded types to be loaded. * @return A map of the given type descriptions pointing to their loaded representations. */ public static Map> load(@MaybeNull ClassLoader classLoader, Map types) { return load(classLoader, types, ClassLoadingStrategy.NO_PROTECTION_DOMAIN, PersistenceHandler.LATENT, PackageDefinitionStrategy.Trivial.INSTANCE, false, true); } /** * Loads a given set of class descriptions and their binary representations. * * @param classLoader The parent class loader. * @param types The unloaded types to be loaded. * @param protectionDomain The protection domain to apply where {@code null} references an implicit protection domain. * @param persistenceHandler The persistence handler of the created class loader. * @param packageDefinitionStrategy The package definer to be queried for package definitions. * @param forbidExisting {@code true} if the class loading should throw an exception if a class was already loaded by a parent class loader. * @param sealed {@code true} if the class loader should be sealed. * @return A map of the given type descriptions pointing to their loaded representations. */ @SuppressFBWarnings(value = "DP_CREATE_CLASSLOADER_INSIDE_DO_PRIVILEGED", justification = "Assuring privilege is explicit user responsibility.") public static Map> load(@MaybeNull ClassLoader classLoader, Map types, @MaybeNull ProtectionDomain protectionDomain, PersistenceHandler persistenceHandler, PackageDefinitionStrategy packageDefinitionStrategy, boolean forbidExisting, boolean sealed) { Map typesByName = new HashMap(); for (Map.Entry entry : types.entrySet()) { typesByName.put(entry.getKey().getName(), entry.getValue()); } classLoader = new ByteArrayClassLoader(classLoader, sealed, typesByName, protectionDomain, persistenceHandler, packageDefinitionStrategy, ClassFilePostProcessor.NoOp.INSTANCE); Map> result = new LinkedHashMap>(); for (TypeDescription typeDescription : types.keySet()) { try { Class type = Class.forName(typeDescription.getName(), false, classLoader); if (!GraalImageCode.getCurrent().isNativeImageExecution() && forbidExisting && type.getClassLoader() != classLoader) { throw new IllegalStateException("Class already loaded: " + type); } result.put(typeDescription, type); } catch (ClassNotFoundException exception) { throw new IllegalStateException("Cannot load class " + typeDescription, exception); } } return result; } @Override protected Map> doDefineClasses(Map typeDefinitions) throws ClassNotFoundException { Map previous = new HashMap(); for (Map.Entry entry : typeDefinitions.entrySet()) { previous.put(entry.getKey(), this.typeDefinitions.putIfAbsent(entry.getKey(), entry.getValue())); } try { Map> types = new LinkedHashMap>(); for (String name : typeDefinitions.keySet()) { synchronized (SYNCHRONIZATION_STRATEGY.initialize().getClassLoadingLock(this, name)) { types.put(name, loadClass(name)); } } return types; } finally { for (Map.Entry entry : previous.entrySet()) { if (entry.getValue() == null) { persistenceHandler.release(entry.getKey(), this.typeDefinitions); } else { this.typeDefinitions.put(entry.getKey(), entry.getValue()); } } } } /** * {@inheritDoc} */ protected Class findClass(String name) throws ClassNotFoundException { byte[] binaryRepresentation = persistenceHandler.lookup(name, typeDefinitions); if (binaryRepresentation == null) { throw new ClassNotFoundException(name); } else { return doPrivileged(new ClassDefinitionAction(name, classFilePostProcessor.transform(this, name, protectionDomain, binaryRepresentation)), accessControlContext); } } /** * {@inheritDoc} */ @MaybeNull protected URL findResource(String name) { return persistenceHandler.url(name, typeDefinitions); } /** * {@inheritDoc} */ protected Enumeration findResources(String name) { URL url = persistenceHandler.url(name, typeDefinitions); return url == null ? EmptyEnumeration.INSTANCE : new SingletonEnumeration(url); } /** * Returns the package for a given name. * * @param name The name of the package. * @return A suitable package or {@code null} if no such package exists. */ @MaybeNull @SuppressWarnings("deprecation") private Package doGetPackage(String name) { return getPackage(name); } /** * An engine for receiving a class loading lock when loading a class. */ protected interface SynchronizationStrategy { /** * Receives the class loading lock. * * @param name The name of the class being loaded. * @param classLoader The class loader loading the class. * @return The corresponding class loading lock. */ Object getClassLoadingLock(ByteArrayClassLoader classLoader, String name); /** * An uninitialized synchronization strategy. */ interface Initializable { /** * Initializes this synchronization strategy. * * @return The synchronization strategy to use. */ SynchronizationStrategy initialize(); } /** * A creation action for a synchronization strategy. */ enum CreationAction implements PrivilegedAction { /** * The singleton instance. */ INSTANCE; /** * {@inheritDoc} */ @SuppressFBWarnings(value = "REC_CATCH_EXCEPTION", justification = "Exception should not be rethrown but trigger a fallback.") public Initializable run() { try { try { Class methodType = Class.forName("java.lang.invoke.MethodType"), methodHandle = Class.forName("java.lang.invoke.MethodHandle"); return new ForJava8CapableVm(Class.forName("java.lang.invoke.MethodHandles$Lookup") .getMethod("findVirtual", Class.class, String.class, methodType) .invoke(ByteArrayClassLoader.methodHandle(), ClassLoader.class, "getClassLoadingLock", methodType.getMethod("methodType", Class.class, Class[].class).invoke(null, Object.class, new Class[]{String.class})), methodHandle.getMethod("bindTo", Object.class), methodHandle.getMethod("invokeWithArguments", Object[].class)); } catch (Exception ignored) { // On the bootstrap class loader, a lookup instance cannot be located reflectively. To avoid issuing a warning for accessing // a protected method from outside of a class that is caused if the module system does not offer accessing the method. return ClassFileVersion.ofThisVm(ClassFileVersion.JAVA_V5).isAtLeast(ClassFileVersion.JAVA_V9) && ByteArrayClassLoader.class.getClassLoader() == null ? SynchronizationStrategy.ForLegacyVm.INSTANCE : new ForJava7CapableVm(ClassLoader.class.getDeclaredMethod("getClassLoadingLock", String.class)); } } catch (Exception ignored) { return SynchronizationStrategy.ForLegacyVm.INSTANCE; } } } /** * A synchronization engine for a VM that is not aware of parallel-capable class loaders. */ enum ForLegacyVm implements SynchronizationStrategy, Initializable { /** * The singleton instance. */ INSTANCE; /** * {@inheritDoc} */ public Object getClassLoadingLock(ByteArrayClassLoader classLoader, String name) { return classLoader; } /** * {@inheritDoc} */ public SynchronizationStrategy initialize() { return this; } } /** * A synchronization engine for a VM that is aware of parallel-capable class loaders. */ @HashCodeAndEqualsPlugin.Enhance class ForJava7CapableVm implements SynchronizationStrategy, Initializable { /** * The {@code ClassLoader#getClassLoadingLock(String)} method. */ private final Method method; /** * Creates a new synchronization strategy. * * @param method The {@code ClassLoader#getClassLoadingLock(String)} method. */ protected ForJava7CapableVm(Method method) { this.method = method; } /** * {@inheritDoc} */ public Object getClassLoadingLock(ByteArrayClassLoader classLoader, String name) { try { return method.invoke(classLoader, name); } catch (IllegalAccessException exception) { throw new IllegalStateException(exception); } catch (InvocationTargetException exception) { throw new IllegalStateException(exception.getTargetException()); } } /** * {@inheritDoc} */ @SuppressFBWarnings(value = "DP_DO_INSIDE_DO_PRIVILEGED", justification = "Assuring privilege is explicit user responsibility.") public SynchronizationStrategy initialize() { try { method.setAccessible(true); return this; } catch (Exception ignored) { return ForLegacyVm.INSTANCE; } } } /** * A synchronization engine for a VM that is aware of parallel-capable class loaders using method handles to respect module boundaries. */ @HashCodeAndEqualsPlugin.Enhance class ForJava8CapableVm implements SynchronizationStrategy, Initializable { /** * The {@code java.lang.invoke.MethodHandle} to use. */ private final Object methodHandle; /** * The {@code java.lang.invoke.MethodHandle#bindTo(Object)} method. */ private final Method bindTo; /** * The {@code java.lang.invoke.MethodHandle#invokeWithArguments(Object[])} method. */ private final Method invokeWithArguments; /** * Creates a new synchronization strategy. * * @param methodHandle The {@code java.lang.invoke.MethodHandle} to use. * @param bindTo The {@code java.lang.invoke.MethodHandle#bindTo(Object)} method. * @param invokeWithArguments The {@code java.lang.invoke.MethodHandle#invokeWithArguments(Object[])} method. */ protected ForJava8CapableVm(Object methodHandle, Method bindTo, Method invokeWithArguments) { this.methodHandle = methodHandle; this.bindTo = bindTo; this.invokeWithArguments = invokeWithArguments; } /** * {@inheritDoc} */ public SynchronizationStrategy initialize() { return this; } /** * {@inheritDoc} */ public Object getClassLoadingLock(ByteArrayClassLoader classLoader, String name) { try { return invokeWithArguments.invoke(bindTo.invoke(methodHandle, classLoader), (Object) new Object[]{name}); } catch (IllegalAccessException exception) { throw new IllegalStateException(exception); } catch (InvocationTargetException exception) { throw new IllegalStateException(exception.getTargetException()); } } } } /** * An action for defining a located class that is not yet loaded. */ @HashCodeAndEqualsPlugin.Enhance(includeSyntheticFields = true) protected class ClassDefinitionAction implements PrivilegedAction> { /** * The binary name of the class to define. */ private final String name; /** * The binary representation of the class to be loaded. */ private final byte[] binaryRepresentation; /** * Creates a new class definition action. * * @param name The binary name of the class to define. * @param binaryRepresentation The binary representation of the class to be loaded. */ protected ClassDefinitionAction(String name, byte[] binaryRepresentation) { this.name = name; this.binaryRepresentation = binaryRepresentation; } /** * {@inheritDoc} */ public Class run() { int packageIndex = name.lastIndexOf('.'); if (packageIndex != -1) { String packageName = name.substring(0, packageIndex); PackageDefinitionStrategy.Definition definition = packageDefinitionStrategy.define(ByteArrayClassLoader.this, packageName, name); if (definition.isDefined()) { Package definedPackage = PACKAGE_LOOKUP_STRATEGY.apply(ByteArrayClassLoader.this, packageName); if (definedPackage == null) { definePackage(packageName, definition.getSpecificationTitle(), definition.getSpecificationVersion(), definition.getSpecificationVendor(), definition.getImplementationTitle(), definition.getImplementationVersion(), definition.getImplementationVendor(), definition.getSealBase()); } else if (!definition.isCompatibleTo(definedPackage)) { throw new SecurityException("Sealing violation for package " + packageName); } } } return defineClass(name, binaryRepresentation, FROM_BEGINNING, binaryRepresentation.length, protectionDomain); } } /** * A package lookup strategy for locating a package by name. */ protected interface PackageLookupStrategy { /** * Returns a package for a given byte array class loader and a name. * * @param classLoader The class loader to locate a package for. * @param name The name of the package. * @return A suitable package or {@code null} if no such package exists. */ @MaybeNull Package apply(ByteArrayClassLoader classLoader, String name); /** * A creation action for a package lookup strategy. */ enum CreationAction implements PrivilegedAction { /** * The singleton instance. */ INSTANCE; /** * {@inheritDoc} */ @SuppressFBWarnings(value = "REC_CATCH_EXCEPTION", justification = "Exception should not be rethrown but trigger a fallback.") public PackageLookupStrategy run() { if (JavaModule.isSupported()) { // Avoid accidental lookup of method with same name in Java 8 J9 VM. try { return new PackageLookupStrategy.ForJava9CapableVm(ClassLoader.class.getMethod("getDefinedPackage", String.class)); } catch (Exception ignored) { return PackageLookupStrategy.ForLegacyVm.INSTANCE; } } else { return PackageLookupStrategy.ForLegacyVm.INSTANCE; } } } /** * A package lookup strategy for a VM prior to Java 9. */ enum ForLegacyVm implements PackageLookupStrategy { /** * The singleton instance. */ INSTANCE; /** * {@inheritDoc} */ @MaybeNull public Package apply(ByteArrayClassLoader classLoader, String name) { return classLoader.doGetPackage(name); } } /** * A package lookup strategy for Java 9 or newer. */ @HashCodeAndEqualsPlugin.Enhance class ForJava9CapableVm implements PackageLookupStrategy { /** * The {@code java.lang.ClassLoader#getDefinedPackage(String)} method. */ private final Method getDefinedPackage; /** * Creates a new package lookup strategy for a modern VM. * * @param getDefinedPackage The {@code java.lang.ClassLoader#getDefinedPackage(String)} method. */ protected ForJava9CapableVm(Method getDefinedPackage) { this.getDefinedPackage = getDefinedPackage; } /** * {@inheritDoc} */ @MaybeNull public Package apply(ByteArrayClassLoader classLoader, String name) { try { return (Package) getDefinedPackage.invoke(classLoader, name); } catch (IllegalAccessException exception) { throw new IllegalStateException(exception); } catch (InvocationTargetException exception) { throw new IllegalStateException(exception.getTargetException()); } } } } /** * A persistence handler decides on whether the byte array that represents a loaded class is exposed by * the {@link java.lang.ClassLoader#getResourceAsStream(String)} method. */ public enum PersistenceHandler { /** * The manifest persistence handler retains all class file representations and makes them accessible. */ MANIFEST(true) { @Override protected byte[] lookup(String name, ConcurrentMap typeDefinitions) { return typeDefinitions.get(name); } @Override protected URL url(String resourceName, ConcurrentMap typeDefinitions) { if (!resourceName.endsWith(CLASS_FILE_SUFFIX)) { return NO_URL; } else if (resourceName.startsWith("/")) { resourceName = resourceName.substring(1); } String typeName = resourceName.replace('/', '.').substring(FROM_BEGINNING, resourceName.length() - CLASS_FILE_SUFFIX.length()); byte[] binaryRepresentation = typeDefinitions.get(typeName); return binaryRepresentation == null ? NO_URL : doPrivileged(new UrlDefinitionAction(resourceName, binaryRepresentation)); } @Override protected void release(String name, ConcurrentMap typeDefinitions) { /* do nothing */ } }, /** * The latent persistence handler hides all class file representations and does not make them accessible * even before they are loaded. */ LATENT(false) { @Override protected byte[] lookup(String name, ConcurrentMap typeDefinitions) { return typeDefinitions.remove(name); } @Override protected URL url(String resourceName, ConcurrentMap typeDefinitions) { return NO_URL; } @Override protected void release(String name, ConcurrentMap typeDefinitions) { typeDefinitions.remove(name); } }; /** * The suffix of files in the Java class file format. */ private static final String CLASS_FILE_SUFFIX = ".class"; /** * {@code true} if this persistence handler represents manifest class file storage. */ private final boolean manifest; /** * Creates a new persistence handler. * * @param manifest {@code true} if this persistence handler represents manifest class file storage. */ PersistenceHandler(boolean manifest) { this.manifest = manifest; } /** * Checks if this persistence handler represents manifest class file storage. * * @return {@code true} if this persistence handler represents manifest class file storage. */ public boolean isManifest() { return manifest; } /** * Performs a lookup of a class file by its name. * * @param name The name of the class to be loaded. * @param typeDefinitions A map of fully qualified class names pointing to their binary representations. * @return The byte array representing the requested class or {@code null} if no such class is known. */ @MaybeNull protected abstract byte[] lookup(String name, ConcurrentMap typeDefinitions); /** * Returns a URL representing a class file. * * @param resourceName The name of the requested resource. * @param typeDefinitions A mapping of byte arrays by their type names. * @return A URL representing the type definition or {@code null} if the requested resource does not represent a class file. */ @MaybeNull protected abstract URL url(String resourceName, ConcurrentMap typeDefinitions); /** * Removes the binary representation of the supplied type if this class loader is latent. * * @param name The name of the type. * @param typeDefinitions A mapping of byte arrays by their type names. */ protected abstract void release(String name, ConcurrentMap typeDefinitions); /** * An action to define a URL that represents a class file. */ @HashCodeAndEqualsPlugin.Enhance protected static class UrlDefinitionAction implements PrivilegedAction { /** * A dispatcher for creating URLs. */ private static final Dispatcher DISPATCHER = doPrivileged(JavaDispatcher.of(Dispatcher.class)); /** * The URL's encoding character set. */ private static final String ENCODING = "UTF-8"; /** * A value to define a standard port as Byte Buddy's URLs do not represent a port. */ private static final int NO_PORT = -1; /** * Indicates that Byte Buddy's URLs do not have a file segment. */ private static final String NO_FILE = ""; /** * The name of the type that this URL represents. */ private final String typeName; /** * The binary representation of the type's class file. */ private final byte[] binaryRepresentation; /** * Creates a new URL definition action. * * @param typeName The name of the type that this URL represents. * @param binaryRepresentation The binary representation of the type's class file. */ protected UrlDefinitionAction(String typeName, byte[] binaryRepresentation) { this.typeName = typeName; this.binaryRepresentation = binaryRepresentation; } /** * A proxy for {@code java.security.AccessController#doPrivileged} that is activated if available. * * @param action The action to execute from a privileged context. * @param The type of the action's resolved value. * @return The action's resolved value. */ @AccessControllerPlugin.Enhance private static T doPrivileged(PrivilegedAction action) { return action.run(); } /** * {@inheritDoc} */ public URL run() { try { String path = URLEncoder.encode(typeName.replace('.', '/'), ENCODING); URLStreamHandler handler = new ByteArrayUrlStreamHandler(binaryRepresentation); URL url = DISPATCHER.of(URI.create(URL_SCHEMA + "://" + path), handler); return url == null ? DISPATCHER.make(URL_SCHEMA, path, NO_PORT, NO_FILE, handler) : url; } catch (MalformedURLException exception) { throw new IllegalStateException("Cannot create URL for " + typeName, exception); } catch (UnsupportedEncodingException exception) { throw new IllegalStateException("Could not find encoding: " + ENCODING, exception); } } /** * A stream handler that returns the given binary representation. */ @HashCodeAndEqualsPlugin.Enhance protected static class ByteArrayUrlStreamHandler extends URLStreamHandler { /** * The binary representation of a type's class file. */ private final byte[] binaryRepresentation; /** * Creates a new byte array URL stream handler. * * @param binaryRepresentation The binary representation of a type's class file. */ protected ByteArrayUrlStreamHandler(byte[] binaryRepresentation) { this.binaryRepresentation = binaryRepresentation; } /** * {@inheritDoc} */ protected URLConnection openConnection(URL url) { return new ByteArrayUrlConnection(url, new ByteArrayInputStream(binaryRepresentation)); } /** * A URL connection for a given byte array. */ protected static class ByteArrayUrlConnection extends URLConnection { /** * The input stream to return for this connection. */ private final InputStream inputStream; /** * Creates a new byte array URL connection. * * @param url The URL that this connection represents. * @param inputStream The input stream to return from this connection. */ protected ByteArrayUrlConnection(URL url, InputStream inputStream) { super(url); this.inputStream = inputStream; } /** * {@inheritDoc} */ public void connect() { connected = true; } /** * {@inheritDoc} */ public InputStream getInputStream() { connect(); // Mimics the semantics of an actual URL connection. return inputStream; } } } /** * A dispatcher for interacting with {@link URL}. */ @JavaDispatcher.Proxied("java.net.URL") protected interface Dispatcher { /** * Creates a {@link URL}. * * @param protocol The URL's protocol. * @param host The host on the URL. * @param port The port on the URL or a negative value if no port is defined. * @param file The file on the URL. * @param handler The stream handler to use. * @return An appropriate URL. * @throws MalformedURLException If the supplied URL is malformed. */ @JavaDispatcher.IsConstructor URL make(String protocol, String host, int port, String file, URLStreamHandler handler) throws MalformedURLException; /** * Resolves a URL from an URI, if possible. * * @param uri The URI to represent. * @param handler The stream handler to attach to that URL. * @return An appropriate URL. * @throws MalformedURLException If the supplied URL is malformed. */ @MaybeNull @JavaDispatcher.IsStatic @JavaDispatcher.Defaults URL of(URI uri, URLStreamHandler handler) throws MalformedURLException; } } } /** *

* A {@link net.bytebuddy.dynamic.loading.ByteArrayClassLoader} which applies child-first semantics for the * given type definitions. *

*

* Important: Package definitions remain their parent-first semantics as loaded package definitions do not expose their class loaders. * Also, it is not possible to make this class or its subclass parallel-capable as the loading strategy is overridden. *

*/ public static class ChildFirst extends ByteArrayClassLoader { /** * The suffix of files in the Java class file format. */ private static final String CLASS_FILE_SUFFIX = ".class"; /* * Register class loader as parallel capable if the current VM supports it. */ static { doRegisterAsParallelCapable(); } /** * Registers class loader as parallel capable if possible. */ @SuppressFBWarnings(value = "DP_DO_INSIDE_DO_PRIVILEGED", justification = "Must be invoked from targeting class loader type.") private static void doRegisterAsParallelCapable() { try { Method method = ClassLoader.class.getDeclaredMethod("registerAsParallelCapable"); method.setAccessible(true); method.invoke(null); } catch (Throwable ignored) { /* do nothing */ } } /** * Creates a new child-first byte array class loader. * * @param parent The {@link java.lang.ClassLoader} that is the parent of this class loader. * @param typeDefinitions A map of fully qualified class names pointing to their binary representations. */ public ChildFirst(@MaybeNull ClassLoader parent, Map typeDefinitions) { super(parent, typeDefinitions); } /** * Creates a new child-first byte array class loader. * * @param parent The {@link java.lang.ClassLoader} that is the parent of this class loader. * @param sealed {@code true} if this class loader is sealed. * @param typeDefinitions A map of fully qualified class names pointing to their binary representations. */ public ChildFirst(@MaybeNull ClassLoader parent, boolean sealed, Map typeDefinitions) { super(parent, sealed, typeDefinitions); } /** * Creates a new child-first byte array class loader. * * @param parent The {@link java.lang.ClassLoader} that is the parent of this class loader. * @param typeDefinitions A map of fully qualified class names pointing to their binary representations. * @param persistenceHandler The persistence handler of this class loader. */ public ChildFirst(@MaybeNull ClassLoader parent, Map typeDefinitions, PersistenceHandler persistenceHandler) { super(parent, typeDefinitions, persistenceHandler); } /** * Creates a new child-first byte array class loader. * * @param parent The {@link java.lang.ClassLoader} that is the parent of this class loader. * @param sealed {@code true} if this class loader is sealed. * @param typeDefinitions A map of fully qualified class names pointing to their binary representations. * @param persistenceHandler The persistence handler of this class loader. */ public ChildFirst(@MaybeNull ClassLoader parent, boolean sealed, Map typeDefinitions, PersistenceHandler persistenceHandler) { super(parent, sealed, typeDefinitions, persistenceHandler); } /** * Creates a new child-first byte array class loader. * * @param parent The {@link java.lang.ClassLoader} that is the parent of this class loader. * @param typeDefinitions A map of fully qualified class names pointing to their binary representations. * @param protectionDomain The protection domain to apply where {@code null} references an implicit protection domain. * @param persistenceHandler The persistence handler of this class loader. * @param packageDefinitionStrategy The package definer to be queried for package definitions. */ public ChildFirst(@MaybeNull ClassLoader parent, Map typeDefinitions, @MaybeNull ProtectionDomain protectionDomain, PersistenceHandler persistenceHandler, PackageDefinitionStrategy packageDefinitionStrategy) { super(parent, typeDefinitions, protectionDomain, persistenceHandler, packageDefinitionStrategy); } /** * Creates a new child-first byte array class loader. * * @param parent The {@link java.lang.ClassLoader} that is the parent of this class loader. * @param sealed {@code true} if this class loader is sealed. * @param typeDefinitions A map of fully qualified class names pointing to their binary representations. * @param protectionDomain The protection domain to apply where {@code null} references an implicit protection domain. * @param persistenceHandler The persistence handler of this class loader. * @param packageDefinitionStrategy The package definer to be queried for package definitions. */ public ChildFirst(@MaybeNull ClassLoader parent, boolean sealed, Map typeDefinitions, @MaybeNull ProtectionDomain protectionDomain, PersistenceHandler persistenceHandler, PackageDefinitionStrategy packageDefinitionStrategy) { super(parent, sealed, typeDefinitions, protectionDomain, persistenceHandler, packageDefinitionStrategy); } /** * Creates a new child-first byte array class loader. * * @param parent The {@link java.lang.ClassLoader} that is the parent of this class loader. * @param typeDefinitions A map of fully qualified class names pointing to their binary representations. * @param protectionDomain The protection domain to apply where {@code null} references an implicit protection domain. * @param persistenceHandler The persistence handler of this class loader. * @param packageDefinitionStrategy The package definer to be queried for package definitions. * @param classFilePostProcessor A post processor for class files to apply p */ public ChildFirst(@MaybeNull ClassLoader parent, Map typeDefinitions, @MaybeNull ProtectionDomain protectionDomain, PersistenceHandler persistenceHandler, PackageDefinitionStrategy packageDefinitionStrategy, ClassFilePostProcessor classFilePostProcessor) { super(parent, typeDefinitions, protectionDomain, persistenceHandler, packageDefinitionStrategy, classFilePostProcessor); } /** * Creates a new child-first byte array class loader. * * @param parent The {@link java.lang.ClassLoader} that is the parent of this class loader. * @param sealed {@code true} if this class loader is sealed. * @param typeDefinitions A map of fully qualified class names pointing to their binary representations. * @param protectionDomain The protection domain to apply where {@code null} references an implicit protection domain. * @param persistenceHandler The persistence handler of this class loader. * @param packageDefinitionStrategy The package definer to be queried for package definitions. * @param classFilePostProcessor A post processor for class files to apply p */ public ChildFirst(@MaybeNull ClassLoader parent, boolean sealed, Map typeDefinitions, @MaybeNull ProtectionDomain protectionDomain, PersistenceHandler persistenceHandler, PackageDefinitionStrategy packageDefinitionStrategy, ClassFilePostProcessor classFilePostProcessor) { super(parent, sealed, typeDefinitions, protectionDomain, persistenceHandler, packageDefinitionStrategy, classFilePostProcessor); } /** * Loads a given set of class descriptions and their binary representations using a child-first class loader. * * @param classLoader The parent class loader. * @param types The unloaded types to be loaded. * @return A map of the given type descriptions pointing to their loaded representations. */ public static Map> load(@MaybeNull ClassLoader classLoader, Map types) { return load(classLoader, types, ClassLoadingStrategy.NO_PROTECTION_DOMAIN, PersistenceHandler.LATENT, PackageDefinitionStrategy.Trivial.INSTANCE, false, true); } /** * Loads a given set of class descriptions and their binary representations using a child-first class loader. * * @param classLoader The parent class loader. * @param types The unloaded types to be loaded. * @param protectionDomain The protection domain to apply where {@code null} references an implicit protection domain. * @param persistenceHandler The persistence handler of the created class loader. * @param packageDefinitionStrategy The package definer to be queried for package definitions. * @param forbidExisting {@code true} if the class loading should throw an exception if a class was already loaded by a parent class loader. * @param sealed {@code true} if the class loader should be sealed. * @return A map of the given type descriptions pointing to their loaded representations. */ @SuppressFBWarnings(value = "DP_CREATE_CLASSLOADER_INSIDE_DO_PRIVILEGED", justification = "Assuring privilege is explicit user responsibility.") public static Map> load(@MaybeNull ClassLoader classLoader, Map types, @MaybeNull ProtectionDomain protectionDomain, PersistenceHandler persistenceHandler, PackageDefinitionStrategy packageDefinitionStrategy, boolean forbidExisting, boolean sealed) { Map typesByName = new HashMap(); for (Map.Entry entry : types.entrySet()) { typesByName.put(entry.getKey().getName(), entry.getValue()); } classLoader = new ChildFirst(classLoader, sealed, typesByName, protectionDomain, persistenceHandler, packageDefinitionStrategy, ClassFilePostProcessor.NoOp.INSTANCE); Map> result = new LinkedHashMap>(); for (TypeDescription typeDescription : types.keySet()) { try { Class type = Class.forName(typeDescription.getName(), false, classLoader); if (!GraalImageCode.getCurrent().isNativeImageExecution() && forbidExisting && type.getClassLoader() != classLoader) { throw new IllegalStateException("Class already loaded: " + type); } result.put(typeDescription, type); } catch (ClassNotFoundException exception) { throw new IllegalStateException("Cannot load class " + typeDescription, exception); } } return result; } /** * {@inheritDoc} */ protected Class loadClass(String name, boolean resolve) throws ClassNotFoundException { synchronized (SYNCHRONIZATION_STRATEGY.initialize().getClassLoadingLock(this, name)) { Class type = findLoadedClass(name); if (type != null) { return type; } try { type = findClass(name); if (resolve) { resolveClass(type); } return type; } catch (ClassNotFoundException exception) { // If an unknown class is loaded, this implementation causes the findClass method of this instance // to be triggered twice. This is however of minor importance because this would result in a // ClassNotFoundException what does not alter the outcome. return super.loadClass(name, resolve); } } } /** * {@inheritDoc} */ public URL getResource(String name) { URL url = persistenceHandler.url(name, typeDefinitions); // If a class resource is defined by this class loader but it is not defined in a manifest manner, // the resource of the parent class loader should be shadowed by 'null'. Note that the delegation // model causes a redundant query to the persistent handler but renders a correct result. return url != null || isShadowed(name) ? url : super.getResource(name); } /** * {@inheritDoc} */ public Enumeration getResources(String name) throws IOException { URL url = persistenceHandler.url(name, typeDefinitions); return url == null ? super.getResources(name) : new PrependingEnumeration(url, super.getResources(name)); } /** * Checks if a resource name represents a class file of a class that was loaded by this class loader. * * @param resource The resource name of the class to be exposed as its class file. * @return {@code true} if this class represents a class that is being loaded by this class loader. */ private boolean isShadowed(String resource) { if (persistenceHandler.isManifest() || !resource.endsWith(CLASS_FILE_SUFFIX)) { return false; } // This synchronization is required to avoid a racing condition to the actual class loading. String name = resource.replace('/', '.').substring(0, resource.length() - CLASS_FILE_SUFFIX.length()); synchronized (SYNCHRONIZATION_STRATEGY.initialize().getClassLoadingLock(this, name)) { if (typeDefinitions.containsKey(name)) { return true; } Class loadedClass = findLoadedClass(name); return loadedClass != null && loadedClass.getClassLoader() == this; } } /** * An enumeration that prepends an element to another enumeration and skips the last element of the provided enumeration. */ protected static class PrependingEnumeration implements Enumeration { /** * The next element to return from this enumeration or {@code null} if such an element does not exist. */ @MaybeNull private URL nextElement; /** * The enumeration from which the next elements should be pulled. */ private final Enumeration enumeration; /** * Creates a new prepending enumeration. * * @param url The first element of the enumeration. * @param enumeration An enumeration that is used for pulling subsequent urls. */ protected PrependingEnumeration(URL url, Enumeration enumeration) { nextElement = url; this.enumeration = enumeration; } /** * {@inheritDoc} */ public boolean hasMoreElements() { return nextElement != null && enumeration.hasMoreElements(); } /** * {@inheritDoc} */ public URL nextElement() { if (nextElement != null && enumeration.hasMoreElements()) { try { return nextElement; } finally { nextElement = enumeration.nextElement(); } } else { throw new NoSuchElementException(); } } } } /** * An enumeration without any elements. */ protected enum EmptyEnumeration implements Enumeration { /** * The singleton instance. */ INSTANCE; /** * {@inheritDoc} */ public boolean hasMoreElements() { return false; } /** * {@inheritDoc} */ public URL nextElement() { throw new NoSuchElementException(); } } /** * An enumeration that contains a single element. */ protected static class SingletonEnumeration implements Enumeration { /** * The current element or {@code null} if this enumeration does not contain further elements. */ @MaybeNull private URL element; /** * Creates a new singleton enumeration. * * @param element The only element. */ protected SingletonEnumeration(URL element) { this.element = element; } /** * {@inheritDoc} */ public boolean hasMoreElements() { return element != null; } /** * {@inheritDoc} */ public URL nextElement() { if (element == null) { throw new NoSuchElementException(); } else { try { return element; } finally { element = null; } } } } }




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