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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;

import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
import net.bytebuddy.agent.builder.AgentBuilder;
import net.bytebuddy.build.AccessControllerPlugin;
import net.bytebuddy.build.HashCodeAndEqualsPlugin;
import net.bytebuddy.description.NamedElement;
import net.bytebuddy.description.type.TypeDescription;
import net.bytebuddy.dynamic.loading.ClassLoadingStrategy;
import net.bytebuddy.matcher.ElementMatcher;
import net.bytebuddy.utility.JavaModule;
import net.bytebuddy.utility.JavaType;
import net.bytebuddy.utility.StreamDrainer;
import net.bytebuddy.utility.dispatcher.JavaDispatcher;
import net.bytebuddy.utility.nullability.AlwaysNull;
import net.bytebuddy.utility.nullability.MaybeNull;

import java.io.*;
import java.lang.instrument.ClassFileTransformer;
import java.lang.instrument.Instrumentation;
import java.lang.instrument.UnmodifiableClassException;
import java.lang.ref.WeakReference;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.net.URL;
import java.net.URLClassLoader;
import java.security.PrivilegedAction;
import java.security.ProtectionDomain;
import java.util.*;
import java.util.jar.JarFile;
import java.util.regex.Pattern;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;

import static net.bytebuddy.matcher.ElementMatchers.isChildOf;

/**
 * Locates a class file or its byte array representation when it is given its type description.
 */
public interface ClassFileLocator extends Closeable {

    /**
     * The file extension for a Java class file.
     */
    String CLASS_FILE_EXTENSION = ".class";

    /**
     * Locates the class file for a given type and returns the binary data of the class file.
     *
     * @param name The name of the type to locate a class file representation for.
     * @return Any binary representation of the type which might be illegal.
     * @throws java.io.IOException If reading a class file causes an error.
     */
    Resolution locate(String name) throws IOException;

    /**
     * Represents a class file as binary data.
     */
    interface Resolution {

        /**
         * Checks if this binary representation is valid.
         *
         * @return {@code true} if this binary representation is valid.
         */
        boolean isResolved();

        /**
         * Finds the data of this binary representation. Calling this method is only legal for resolved instances.
         * For non-resolved instances, an exception is thrown.
         *
         * @return The requested binary data. The returned array must not be altered.
         */
        byte[] resolve();

        /**
         * A canonical representation of an illegal binary representation.
         */
        @HashCodeAndEqualsPlugin.Enhance
        class Illegal implements Resolution {

            /**
             * The name of the unresolved class file.
             */
            private final String typeName;

            /**
             * Creates an illegal resolution for a class file.
             *
             * @param typeName The name of the unresolved class file.
             */
            public Illegal(String typeName) {
                this.typeName = typeName;
            }

            /**
             * {@inheritDoc}
             */
            public boolean isResolved() {
                return false;
            }

            /**
             * {@inheritDoc}
             */
            public byte[] resolve() {
                throw new IllegalStateException("Could not locate class file for " + typeName);
            }
        }

        /**
         * Represents a byte array as binary data.
         */
        @HashCodeAndEqualsPlugin.Enhance
        class Explicit implements Resolution {

            /**
             * The represented data.
             */
            private final byte[] binaryRepresentation;

            /**
             * Creates a new explicit resolution of a given array of binary data.
             *
             * @param binaryRepresentation The binary data to represent. The array must not be modified.
             */
            @SuppressFBWarnings(value = "EI_EXPOSE_REP2", justification = "The array is not modified by class contract.")
            public Explicit(byte[] binaryRepresentation) {
                this.binaryRepresentation = binaryRepresentation;
            }

            /**
             * {@inheritDoc}
             */
            public boolean isResolved() {
                return true;
            }

            /**
             * {@inheritDoc}
             */
            @SuppressFBWarnings(value = "EI_EXPOSE_REP", justification = "The array is not modified by class contract.")
            public byte[] resolve() {
                return binaryRepresentation;
            }
        }
    }

    /**
     * A class file locator that cannot locate any class files.
     */
    enum NoOp implements ClassFileLocator {

        /**
         * The singleton instance.
         */
        INSTANCE;

        /**
         * {@inheritDoc}
         */
        public Resolution locate(String name) {
            return new Resolution.Illegal(name);
        }

        /**
         * {@inheritDoc}
         */
        public void close() {
            /* do nothing */
        }
    }

    /**
     * A simple class file locator that returns class files from a selection of given types.
     */
    @HashCodeAndEqualsPlugin.Enhance
    class Simple implements ClassFileLocator {

        /**
         * The class files that are known to this class file locator mapped by their type name.
         */
        private final Map classFiles;

        /**
         * Creates a new simple class file locator.
         *
         * @param classFiles The class files that are known to this class file locator mapped by their type name.
         */
        public Simple(Map classFiles) {
            this.classFiles = classFiles;
        }

        /**
         * Creates a class file locator for a single known type.
         *
         * @param typeName             The name of the type.
         * @param binaryRepresentation The binary representation of the type.
         * @return An appropriate class file locator.
         */
        public static ClassFileLocator of(String typeName, byte[] binaryRepresentation) {
            return new Simple(Collections.singletonMap(typeName, binaryRepresentation));
        }

        /**
         * Creates a class file locator that represents all types of a dynamic type.
         *
         * @param dynamicType The dynamic type to represent.
         * @return A class file locator representing the dynamic type's types.
         */
        public static ClassFileLocator of(DynamicType dynamicType) {
            return of(dynamicType.getAllTypes());
        }

        /**
         * Creates a class file locator that represents all types of a dynamic type.
         *
         * @param binaryRepresentations The binary representation of all types.
         * @return A class file locator representing the dynamic type's types.
         */
        public static ClassFileLocator of(Map binaryRepresentations) {
            Map classFiles = new HashMap();
            for (Map.Entry entry : binaryRepresentations.entrySet()) {
                classFiles.put(entry.getKey().getName(), entry.getValue());
            }
            return new Simple(classFiles);
        }

        /**
         * Creates a class file locator of a map of resources where class files are mapped by their path and file extension.
         *
         * @param binaryRepresentations A map of resource names to their binary representation.
         * @return A class file locator that finds class files within the map.
         */
        public static ClassFileLocator ofResources(Map binaryRepresentations) {
            Map classFiles = new HashMap();
            for (Map.Entry entry : binaryRepresentations.entrySet()) {
                if (entry.getKey().endsWith(CLASS_FILE_EXTENSION)) {
                    classFiles.put(entry.getKey().substring(0, entry.getKey().length() - CLASS_FILE_EXTENSION.length()).replace('/', '.'), entry.getValue());
                }
            }
            return new Simple(classFiles);
        }

        /**
         * {@inheritDoc}
         */
        public Resolution locate(String name) {
            byte[] binaryRepresentation = classFiles.get(name);
            return binaryRepresentation == null
                    ? new Resolution.Illegal(name)
                    : new Resolution.Explicit(binaryRepresentation);
        }

        /**
         * {@inheritDoc}
         */
        public void close() {
            /* do nothing */
        }
    }

    /**
     * 

* A class file locator that queries a class loader for binary representations of class files. *

*

* Important: Even when calling {@link Closeable#close()} on this class file locator, no underlying * class loader is closed if it implements the {@link Closeable} interface as this is typically not intended. *

*/ @HashCodeAndEqualsPlugin.Enhance class ForClassLoader implements ClassFileLocator { /** * A class loader that does not define resources of its own but allows querying for resources supplied by the boot loader. */ private static final ClassLoader BOOT_LOADER_PROXY = doPrivileged(BootLoaderProxyCreationAction.INSTANCE); /** * The class loader to query. */ private final ClassLoader classLoader; /** * Creates a new class file locator for the given class loader. * * @param classLoader The class loader to query which must not be the bootstrap class loader, i.e. {@code null}. */ protected ForClassLoader(ClassLoader classLoader) { this.classLoader = classLoader; } /** * 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(); } /** * Creates a class file locator that queries the system class loader. * * @return A class file locator that queries the system class loader. */ public static ClassFileLocator ofSystemLoader() { return new ForClassLoader(ClassLoader.getSystemClassLoader()); } /** * Creates a class file locator that queries the plaform class loader or the extension class loader if the * current VM is not at least of version 9. * * @return A class file locator that queries the plaform class loader or the extension class loader. */ public static ClassFileLocator ofPlatformLoader() { return of(ClassLoader.getSystemClassLoader().getParent()); } /** * Creates a class file locator that queries the boot loader. * * @return A class file locator that queries the boot loader. */ public static ClassFileLocator ofBootLoader() { return new ForClassLoader(BOOT_LOADER_PROXY); } /** * Creates a class file locator for a given class loader. * * @param classLoader The class loader to be used which might be {@code null} to represent the bootstrap loader. * @return A corresponding source locator. */ public static ClassFileLocator of(@MaybeNull ClassLoader classLoader) { return new ForClassLoader(classLoader == null ? BOOT_LOADER_PROXY : classLoader); } /** * Attempts to create a binary representation of a loaded type by requesting data from its * {@link java.lang.ClassLoader}. * * @param type The type of interest. * @return The binary representation of the supplied type. */ public static byte[] read(Class type) { try { ClassLoader classLoader = type.getClassLoader(); return locate(classLoader == null ? BOOT_LOADER_PROXY : classLoader, TypeDescription.ForLoadedType.getName(type)).resolve(); } catch (IOException exception) { throw new IllegalStateException("Cannot read class file for " + type, exception); } } /** * Attempts to create a binary representation of several loaded types by requesting * data from their respective {@link java.lang.ClassLoader}s. * * @param type The types of interest. * @return A mapping of the supplied types to their binary representation. */ public static Map, byte[]> read(Class... type) { return read(Arrays.asList(type)); } /** * Attempts to create a binary representation of several loaded types by requesting * data from their respective {@link java.lang.ClassLoader}s. * * @param types The types of interest. * @return A mapping of the supplied types to their binary representation. */ public static Map, byte[]> read(Collection> types) { Map, byte[]> result = new HashMap, byte[]>(); for (Class type : types) { result.put(type, read(type)); } return result; } /** * Attempts to create a binary representation of several loaded types by requesting * data from their respective {@link java.lang.ClassLoader}s. * * @param type The types of interest. * @return A mapping of the supplied types' names to their binary representation. */ public static Map readToNames(Class... type) { return readToNames(Arrays.asList(type)); } /** * Attempts to create a binary representation of several loaded types by requesting * data from their respective {@link java.lang.ClassLoader}s. * * @param types The types of interest. * @return A mapping of the supplied types' names to their binary representation. */ public static Map readToNames(Collection> types) { Map result = new HashMap(); for (Class type : types) { result.put(type.getName(), read(type)); } return result; } /** * {@inheritDoc} */ public Resolution locate(String name) throws IOException { return locate(classLoader, name); } /** * {@inheritDoc} */ public void close() { /* do nothing */ } /** * Locates the class file for the supplied type by requesting a resource from the class loader. * * @param classLoader The class loader to query. * @param name The name of the type for which to locate a class file. * @return A resolution for the class file. * @throws IOException If reading the class file causes an exception. */ protected static Resolution locate(ClassLoader classLoader, String name) throws IOException { InputStream inputStream = classLoader.getResourceAsStream(name.replace('.', '/') + CLASS_FILE_EXTENSION); if (inputStream != null) { try { return new Resolution.Explicit(StreamDrainer.DEFAULT.drain(inputStream)); } finally { inputStream.close(); } } else { return new Resolution.Illegal(name); } } /** * A privileged action for creating a proxy class loader for the boot class loader. */ protected enum BootLoaderProxyCreationAction implements PrivilegedAction { /** * The singleton instance. */ INSTANCE; /** * {@inheritDoc} */ public ClassLoader run() { return new URLClassLoader(new URL[0], ClassLoadingStrategy.BOOTSTRAP_LOADER); } } /** *

* A class file locator that queries a class loader for binary representations of class files. * The class loader is only weakly referenced. *

*

* Important: Even when calling {@link Closeable#close()} on this class file locator, no underlying * class loader is closed if it implements the {@link Closeable} interface as this is typically not intended. *

*/ public static class WeaklyReferenced extends WeakReference implements ClassFileLocator { /** * The represented class loader's hash code. */ private final int hashCode; /** * Creates a class file locator for a class loader that is weakly referenced. * * @param classLoader The class loader to represent. */ protected WeaklyReferenced(ClassLoader classLoader) { super(classLoader); hashCode = System.identityHashCode(classLoader); } /** * Creates a class file locator for a given class loader. If the class loader is not the bootstrap * class loader or the system class loader which cannot be collected, the class loader is only weakly * referenced. * * @param classLoader The class loader to be used. If this class loader represents the bootstrap class * loader which is represented by the {@code null} value, this system class loader * is used instead. * @return A corresponding source locator. */ public static ClassFileLocator of(@MaybeNull ClassLoader classLoader) { return classLoader == null || classLoader == ClassLoader.getSystemClassLoader() || classLoader == ClassLoader.getSystemClassLoader().getParent() ? ForClassLoader.of(classLoader) : new WeaklyReferenced(classLoader); } /** * {@inheritDoc} */ public Resolution locate(String name) throws IOException { ClassLoader classLoader = get(); return classLoader == null ? new Resolution.Illegal(name) : ForClassLoader.locate(classLoader, name); } /** * {@inheritDoc} */ public void close() { /* do nothing */ } @Override public int hashCode() { return hashCode; } @Override public boolean equals(@MaybeNull Object other) { if (this == other) { return true; } else if (other == null || getClass() != other.getClass()) { return false; } WeaklyReferenced weaklyReferenced = (WeaklyReferenced) other; ClassLoader classLoader = weaklyReferenced.get(); return classLoader != null && get() == classLoader; } } } /** *

* A class file locator that locates class files by querying a Java module's {@code getResourceAsStream} method. *

*

* Important: Even when calling {@link Closeable#close()} on this class file locator, no underlying * class loader is closed if it implements the {@link Closeable} interface as this is typically not intended. *

*/ @HashCodeAndEqualsPlugin.Enhance class ForModule implements ClassFileLocator { /** * An empty array that can be used to indicate no arguments to avoid an allocation on a reflective call. */ private static final Object[] NO_ARGUMENT = new Object[0]; /** * The represented Java module. */ private final JavaModule module; /** * Creates a new class file locator for a Java module. * * @param module The represented Java module. */ protected ForModule(JavaModule module) { this.module = module; } /** * Returns a class file locator that exposes all class files of the boot module layer. This class file locator is only available * on virtual machines of version 9 or later. On earlier versions, the returned class file locator does not locate any resources. * * @return A class file locator that locates classes of the boot layer. */ @SuppressFBWarnings(value = "REC_CATCH_EXCEPTION", justification = "Exception should always be wrapped for clarity") public static ClassFileLocator ofBootLayer() { try { Map bootModules = new HashMap(); Class layerType = Class.forName("java.lang.ModuleLayer"); Method getPackages = JavaType.MODULE.load().getMethod("getPackages"); for (Object rawModule : (Set) layerType.getMethod("modules").invoke(layerType.getMethod("boot").invoke(null))) { ClassFileLocator classFileLocator = ForModule.of(JavaModule.of(rawModule)); for (Object packageName : (Set) getPackages.invoke(rawModule, NO_ARGUMENT)) { bootModules.put((String) packageName, classFileLocator); } } return new PackageDiscriminating(bootModules); } catch (Exception exception) { throw new IllegalStateException("Cannot process boot layer", exception); } } /** * Returns a class file locator for the provided module. If the provided module is not named, class files are located via this * unnamed module's class loader. * * @param module The module to create a class file locator for. * @return An appropriate class file locator. */ public static ClassFileLocator of(JavaModule module) { return module.isNamed() ? new ForModule(module) : ForClassLoader.of(module.getClassLoader()); } /** * {@inheritDoc} */ public Resolution locate(String name) throws IOException { return locate(module, name); } /** * Creates a resolution for a Java module's class files. * * @param module The Java module to query. * @param typeName The name of the type being queried. * @return A resolution for the query. * @throws IOException If an I/O exception was thrown. */ protected static Resolution locate(JavaModule module, String typeName) throws IOException { InputStream inputStream = module.getResourceAsStream(typeName.replace('.', '/') + CLASS_FILE_EXTENSION); if (inputStream != null) { try { return new Resolution.Explicit(StreamDrainer.DEFAULT.drain(inputStream)); } finally { inputStream.close(); } } else { return new Resolution.Illegal(typeName); } } /** * {@inheritDoc} */ public void close() { /* do nothing */ } /** *

* A class file locator for a Java module that only references this module weakly. If a module was garbage collected, * this class file locator only returns unresolved resolutions. *

*

* Important: Even when calling {@link Closeable#close()} on this class file locator, no underlying * class loader is closed if it implements the {@link Closeable} interface as this is typically not intended. *

*/ public static class WeaklyReferenced extends WeakReference implements ClassFileLocator { /** * The represented module's hash code. */ private final int hashCode; /** * Creates a class file locator for a Java module that is weakly referenced. * * @param module The raw Java module to represent. */ protected WeaklyReferenced(Object module) { super(module); hashCode = System.identityHashCode(module); } /** * Creates a class file locator for a Java module where the module is referenced weakly. If the module is not named, the module's class loader * is represented instead. Module's of the boot layer are not referenced weakly. * * @param module The Java module to represent. * @return A suitable class file locator. */ public static ClassFileLocator of(JavaModule module) { if (module.isNamed()) { return module.getClassLoader() == null || module.getClassLoader() == ClassLoader.getSystemClassLoader() || module.getClassLoader() == ClassLoader.getSystemClassLoader().getParent() ? new ForModule(module) : new WeaklyReferenced(module.unwrap()); } else { return ForClassLoader.WeaklyReferenced.of(module.getClassLoader()); } } /** * {@inheritDoc} */ public Resolution locate(String name) throws IOException { Object module = get(); return module == null ? new Resolution.Illegal(name) : ForModule.locate(JavaModule.of(module), name); } /** * {@inheritDoc} */ public void close() { /* do nothing */ } /** * {@inheritDoc} */ public int hashCode() { return hashCode; } /** * {@inheritDoc} */ public boolean equals(@MaybeNull Object other) { if (this == other) { return true; } else if (other == null || getClass() != other.getClass()) { return false; } WeaklyReferenced weaklyReferenced = (WeaklyReferenced) other; Object module = weaklyReferenced.get(); return module != null && get() == module; } } } /** * A class file locator that locates classes within a Java jar file. */ @HashCodeAndEqualsPlugin.Enhance class ForJarFile implements ClassFileLocator { /** * A list of potential locations of the runtime jar for different platforms. */ private static final List RUNTIME_LOCATIONS = Arrays.asList("lib/rt.jar", "../lib/rt.jar", "../Classes/classes.jar"); /** * The jar file to read from. */ private final JarFile jarFile; /** * Creates a new class file locator for the given jar file. * * @param jarFile The jar file to read from. */ public ForJarFile(JarFile jarFile) { this.jarFile = jarFile; } /** * Creates a new class file locator for the given jar file. * * @param file The jar file to read from. * @return A class file locator for the jar file. * @throws IOException If an I/O exception is thrown. */ public static ClassFileLocator of(File file) throws IOException { return new ForJarFile(new JarFile(file)); } /** * Resolves a class file locator for the class path that reads class files directly from the file system. The resulting * class file locator does not imply classes on the boot path. * * @return A class file locator for the class path. * @throws IOException If an I/O exception occurs. */ public static ClassFileLocator ofClassPath() throws IOException { return ofClassPath(System.getProperty("java.class.path")); } /** *

* Resolves a class file locator for the class path that reads class files directly from the file system. *

*

* Note: The resulting class file locator does not include classes of the bootstrap class loader. *

* * @param classPath The class path to scan with the elements separated by {@code path.separator}. * @return A class file locator for the class path. * @throws IOException If an I/O exception occurs. */ public static ClassFileLocator ofClassPath(String classPath) throws IOException { List classFileLocators = new ArrayList(); for (String element : Pattern.compile(System.getProperty("path.separator"), Pattern.LITERAL).split(classPath)) { File file = new File(element); if (file.isDirectory()) { classFileLocators.add(new ForFolder(file)); } else if (file.isFile()) { classFileLocators.add(of(file)); } } return new Compound(classFileLocators); } /** * Resolves a class file locator for the runtime jar. If such a file does not exist or cannot be located, a runtime exception is thrown. * * @return A class file locator for the runtime jar, if available. * @throws IOException If an I/O exception occurs. */ public static ClassFileLocator ofRuntimeJar() throws IOException { String javaHome = System.getProperty("java.home").replace('\\', '/'); File runtimeJar = null; for (String location : RUNTIME_LOCATIONS) { File candidate = new File(javaHome, location); if (candidate.isFile()) { runtimeJar = candidate; break; } } if (runtimeJar == null) { throw new IllegalStateException("Runtime jar does not exist in " + javaHome + " for any of " + RUNTIME_LOCATIONS); } return of(runtimeJar); } /** * {@inheritDoc} */ public Resolution locate(String name) throws IOException { ZipEntry zipEntry = jarFile.getEntry(name.replace('.', '/') + CLASS_FILE_EXTENSION); if (zipEntry == null) { return new Resolution.Illegal(name); } else { InputStream inputStream = jarFile.getInputStream(zipEntry); try { return new Resolution.Explicit(StreamDrainer.DEFAULT.drain(inputStream)); } finally { inputStream.close(); } } } /** * {@inheritDoc} */ public void close() throws IOException { jarFile.close(); } } /** * A class file locator that locates classes within a Java jmod file. This class file locator should not be used * for reading modular jar files for which {@link ForJarFile} is appropriate. */ @HashCodeAndEqualsPlugin.Enhance class ForModuleFile implements ClassFileLocator { /** * The file extension of a modular Java package. */ private static final String JMOD_FILE_EXTENSION = ".jmod"; /** * A list of potential locations of the boot path for different platforms. */ private static final List BOOT_LOCATIONS = Arrays.asList("jmods", "../jmods", "modules"); /** * The represented jmod file. */ private final ZipFile zipFile; /** * Creates a new class file locator for a jmod file. * * @param zipFile The represented jmod file. */ public ForModuleFile(ZipFile zipFile) { this.zipFile = zipFile; } /** * Creates a new class file locator for this VM's boot module path. * * @return A class file locator for this VM's boot module path. * @throws IOException If an I/O error occurs. */ public static ClassFileLocator ofBootPath() throws IOException { String javaHome = System.getProperty("java.home").replace('\\', '/'); File bootPath = null; for (String location : BOOT_LOCATIONS) { File candidate = new File(javaHome, location); if (candidate.isDirectory()) { bootPath = candidate; break; } } if (bootPath == null) { throw new IllegalStateException("Boot modules do not exist in " + javaHome + " for any of " + BOOT_LOCATIONS); } return ofBootPath(bootPath); } /** * Creates a new class file locator for a Java boot module path. * * @param bootPath The boot path folder. * @return A class file locator for this VMs boot module path. * @throws IOException If an I/O error occurs. */ public static ClassFileLocator ofBootPath(File bootPath) throws IOException { File[] module = bootPath.listFiles(); if (module == null) { return NoOp.INSTANCE; } List classFileLocators = new ArrayList(module.length); for (File aModule : module) { if (aModule.isFile()) { classFileLocators.add(of(aModule)); } else if (aModule.isDirectory()) { // Relevant for locally built OpenJDK. classFileLocators.add(new ForFolder(aModule)); } } return new Compound(classFileLocators); } /** *

* Resolves a class file locator for this VM's Java module path that reads class files directly from the file system. *

*

* Note: The resulting class file locator does not include classes of the bootstrap class loader. *

* * @return A class file locator for the class path. * @throws IOException If an I/O exception occurs. */ public static ClassFileLocator ofModulePath() throws IOException { String modulePath = System.getProperty("jdk.module.path"); return modulePath == null ? NoOp.INSTANCE : ofModulePath(modulePath); } /** *

* Resolves a class file locator for a Java module path that reads class files directly from the file system. All * elements of the module path are resolved relative to this VM's {@code user.dir}. *

*

* Note: The resulting class file locator does not include classes of the bootstrap class loader. *

* * @param modulePath The module path to scan with the elements separated by {@code path.separator}. * @return A class file locator for the class path. * @throws IOException If an I/O exception occurs. */ public static ClassFileLocator ofModulePath(String modulePath) throws IOException { return ofModulePath(modulePath, System.getProperty("user.dir")); } /** *

* Resolves a class file locator for a Java module path that reads class files directly from the file system. *

*

* Note: The resulting class file locator does not include classes of the bootstrap class loader. *

* * @param modulePath The module path to scan with the elements separated by {@code path.separator}. * @param baseFolder The relative location of the elements on the module path. * @return A class file locator for the class path. * @throws IOException If an I/O exception occurs. */ public static ClassFileLocator ofModulePath(String modulePath, String baseFolder) throws IOException { List classFileLocators = new ArrayList(); for (String element : Pattern.compile(System.getProperty("path.separator"), Pattern.LITERAL).split(modulePath)) { File file = new File(baseFolder, element); if (file.isDirectory()) { File[] module = file.listFiles(); if (module != null) { for (File aModule : module) { if (aModule.isDirectory()) { classFileLocators.add(new ForFolder(aModule)); } else if (aModule.isFile()) { classFileLocators.add(aModule.getName().endsWith(JMOD_FILE_EXTENSION) ? of(aModule) : ForJarFile.of(aModule)); } } } } else if (file.isFile()) { classFileLocators.add(file.getName().endsWith(JMOD_FILE_EXTENSION) ? of(file) : ForJarFile.of(file)); } } return new Compound(classFileLocators); } /** * Returns a class file locator for the given module file. * * @param file The module file. * @return A class file locator for the given module * @throws IOException If an I/O error occurs. */ public static ClassFileLocator of(File file) throws IOException { return new ForModuleFile(new ZipFile(file)); } /** * {@inheritDoc} */ public Resolution locate(String name) throws IOException { ZipEntry zipEntry = zipFile.getEntry("classes/" + name.replace('.', '/') + CLASS_FILE_EXTENSION); if (zipEntry == null) { return new Resolution.Illegal(name); } else { InputStream inputStream = zipFile.getInputStream(zipEntry); try { return new Resolution.Explicit(StreamDrainer.DEFAULT.drain(inputStream)); } finally { inputStream.close(); } } } /** * {@inheritDoc} */ public void close() throws IOException { zipFile.close(); } } /** * A class file locator that finds files from a standardized Java folder structure with * folders donating packages and class files being saved as {@code .class} files * within their package folder. */ @HashCodeAndEqualsPlugin.Enhance class ForFolder implements ClassFileLocator { /** * The base folder of the package structure. */ private final File folder; /** * Creates a new class file locator for a folder structure of class files. * * @param folder The base folder of the package structure. */ public ForFolder(File folder) { this.folder = folder; } /** * {@inheritDoc} */ public Resolution locate(String name) throws IOException { File file = new File(folder, name.replace('.', File.separatorChar) + CLASS_FILE_EXTENSION); if (file.exists()) { InputStream inputStream = new FileInputStream(file); try { return new Resolution.Explicit(StreamDrainer.DEFAULT.drain(inputStream)); } finally { inputStream.close(); } } else { return new Resolution.Illegal(name); } } /** * {@inheritDoc} */ public void close() { /* do nothing */ } } /** * A class file locator that reads class files from one or several URLs. The reading is accomplished via using an {@link URLClassLoader}. * Doing so, boot loader resources might be located additionally to those found via the specified URLs. */ @HashCodeAndEqualsPlugin.Enhance class ForUrl implements ClassFileLocator { /** * The class loader that delegates to the URLs. */ private final ClassLoader classLoader; /** * Creates a new class file locator for the given URLs. * * @param url The URLs to search for class files. */ public ForUrl(URL... url) { classLoader = doPrivileged(new ClassLoaderCreationAction(url)); } /** * Creates a new class file locator for the given URLs. * * @param urls The URLs to search for class files. */ public ForUrl(Collection urls) { this(urls.toArray(new URL[0])); } /** * 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 Resolution locate(String name) throws IOException { return ForClassLoader.locate(classLoader, name); } /** * {@inheritDoc} */ public void close() throws IOException { if (classLoader instanceof Closeable) { ((Closeable) classLoader).close(); } } /** * An action to create a class loader with the purpose of locating classes from an URL location. */ @HashCodeAndEqualsPlugin.Enhance protected static class ClassLoaderCreationAction implements PrivilegedAction { /** * The URLs to locate classes from. */ private final URL[] url; /** * Creates a new class loader creation action. * * @param url The URLs to locate classes from. */ protected ClassLoaderCreationAction(URL[] url) { this.url = url; } /** * {@inheritDoc} */ public ClassLoader run() { return new URLClassLoader(url, ClassLoadingStrategy.BOOTSTRAP_LOADER); } } } /** * A Java agent that allows the location of class files by emulating a retransformation. Note that this class file * locator causes a class to be loaded in order to look up its class file. Also, this locator does deliberately not * support the look-up of classes that represent lambda expressions. */ @HashCodeAndEqualsPlugin.Enhance class ForInstrumentation implements ClassFileLocator { /** * A dispatcher for interacting with the instrumentation API. */ private static final Dispatcher DISPATCHER = doPrivileged(JavaDispatcher.of(Dispatcher.class)); /** * The instrumentation instance to use for looking up the binary format of a type. */ private final Instrumentation instrumentation; /** * The delegate to load a class by its name. */ private final ClassLoadingDelegate classLoadingDelegate; /** * Creates an agent-based class file locator. * * @param instrumentation The instrumentation to be used. * @param classLoader The class loader to read a class from or {@code null} to use the boot loader. */ public ForInstrumentation(Instrumentation instrumentation, @MaybeNull ClassLoader classLoader) { this(instrumentation, ClassLoadingDelegate.Default.of(classLoader)); } /** * 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(); } /** * Creates an agent-based class file locator. * * @param instrumentation The instrumentation to be used. * @param classLoadingDelegate The delegate responsible for class loading. */ public ForInstrumentation(Instrumentation instrumentation, ClassLoadingDelegate classLoadingDelegate) { if (!DISPATCHER.isRetransformClassesSupported(instrumentation)) { throw new IllegalArgumentException(instrumentation + " does not support retransformation"); } this.instrumentation = instrumentation; this.classLoadingDelegate = classLoadingDelegate; } /** * Resolves the instrumentation provided by {@code net.bytebuddy.agent.Installer}. * * @return The installed instrumentation instance. */ private static Instrumentation resolveByteBuddyAgentInstrumentation() { try { Class installer = ClassLoader.getSystemClassLoader().loadClass("net.bytebuddy.agent.Installer"); JavaModule source = JavaModule.ofType(AgentBuilder.class), target = JavaModule.ofType(installer); if (source != null && !source.canRead(target)) { Class module = Class.forName("java.lang.Module"); module.getMethod("addReads", module).invoke(source.unwrap(), target.unwrap()); } return (Instrumentation) installer.getMethod("getInstrumentation").invoke(null); } catch (RuntimeException exception) { throw exception; } catch (Exception exception) { throw new IllegalStateException("The Byte Buddy agent is not installed or not accessible", exception); } } /** * Returns an agent-based class file locator for the given class loader and an already installed * Byte Buddy-agent. * * @param classLoader The class loader that is expected to load the looked-up a class. * @return A class file locator for the given class loader based on a Byte Buddy agent. */ public static ClassFileLocator fromInstalledAgent(@MaybeNull ClassLoader classLoader) { return new ForInstrumentation(resolveByteBuddyAgentInstrumentation(), classLoader); } /** * Returns a class file locator that is capable of locating a class file for the given type using the given instrumentation instance. * * @param instrumentation The instrumentation instance to query for a retransformation. * @param type The locatable type which class loader is used as a fallback. * @return A class file locator for locating the class file of the given type. */ public static ClassFileLocator of(Instrumentation instrumentation, Class type) { return new ForInstrumentation(instrumentation, ClassLoadingDelegate.Explicit.of(type)); } /** * {@inheritDoc} */ public Resolution locate(String name) { try { ExtractionClassFileTransformer classFileTransformer = new ExtractionClassFileTransformer(classLoadingDelegate.getClassLoader(), name); DISPATCHER.addTransformer(instrumentation, classFileTransformer, true); try { DISPATCHER.retransformClasses(instrumentation, new Class[]{classLoadingDelegate.locate(name)}); byte[] binaryRepresentation = classFileTransformer.getBinaryRepresentation(); return binaryRepresentation == null ? new Resolution.Illegal(name) : new Resolution.Explicit(binaryRepresentation); } finally { instrumentation.removeTransformer(classFileTransformer); } } catch (RuntimeException exception) { throw exception; } catch (Exception ignored) { return new Resolution.Illegal(name); } } /** * {@inheritDoc} */ public void close() { /* do nothing */ } /** * A dispatcher to interact with the {@link Instrumentation} API. */ @JavaDispatcher.Proxied("java.lang.instrument.Instrumentation") protected interface Dispatcher { /** * Invokes the {@code Instrumentation#isRetransformClassesSupported} method. * * @param instrumentation The instrumentation instance to invoke the method on. * @return {@code true} if the supplied instrumentation instance supports retransformation. */ boolean isRetransformClassesSupported(Instrumentation instrumentation); /** * Registers a transformer. * * @param instrumentation The instrumentation instance to invoke the method on. * @param classFileTransformer The class file transformer to register. * @param canRetransform {@code true} if the class file transformer should be invoked upon a retransformation. */ void addTransformer(Instrumentation instrumentation, ClassFileTransformer classFileTransformer, boolean canRetransform); /** * Retransforms the supplied classes. * * @param instrumentation The instrumentation instance to invoke the method on. * @param type The types to retransform. * @throws UnmodifiableClassException If any of the supplied types are unmodifiable. */ void retransformClasses(Instrumentation instrumentation, Class[] type) throws UnmodifiableClassException; } /** * A delegate that is queried for loading a class. */ public interface ClassLoadingDelegate { /** * Loads a class by its name. * * @param name The name of the type. * @return The class with the given name. * @throws ClassNotFoundException If a class cannot be found. */ Class locate(String name) throws ClassNotFoundException; /** * Returns the underlying class loader. * * @return The underlying class loader. */ @MaybeNull ClassLoader getClassLoader(); /** * A default implementation of a class loading delegate. */ @HashCodeAndEqualsPlugin.Enhance class Default implements ClassLoadingDelegate { /** * A class loader that does not define resources of its own but allows querying for resources supplied by the boot loader. */ private static final ClassLoader BOOT_LOADER_PROXY = doPrivileged(BootLoaderProxyCreationAction.INSTANCE); /** * The underlying class loader. */ protected final ClassLoader classLoader; /** * Creates a default class loading delegate. * * @param classLoader The class loader to be queried. */ protected Default(ClassLoader classLoader) { this.classLoader = classLoader; } /** * Creates a class loading delegate for the given class loader. * * @param classLoader The class loader for which to create a delegate or {@code null} to use the boot loader. * @return The class loading delegate for the provided class loader. */ public static ClassLoadingDelegate of(@MaybeNull ClassLoader classLoader) { return ForDelegatingClassLoader.isDelegating(classLoader) ? new ForDelegatingClassLoader(classLoader) : new Default(classLoader == null ? BOOT_LOADER_PROXY : classLoader); } /** * {@inheritDoc} */ public Class locate(String name) throws ClassNotFoundException { return classLoader.loadClass(name); } /** * {@inheritDoc} */ @MaybeNull public ClassLoader getClassLoader() { return classLoader == BOOT_LOADER_PROXY ? ClassLoadingStrategy.BOOTSTRAP_LOADER : classLoader; } /** * A privileged action for creating a proxy class loader for the boot class loader. */ protected enum BootLoaderProxyCreationAction implements PrivilegedAction { /** * The singleton instance. */ INSTANCE; /** * {@inheritDoc} */ public ClassLoader run() { return new URLClassLoader(new URL[0], ClassLoadingStrategy.BOOTSTRAP_LOADER); } } } /** * A class loading delegate that accounts for a {@code sun.reflect.DelegatingClassLoader} which * cannot load its own classes by name. */ class ForDelegatingClassLoader extends Default { /** * The name of the delegating class loader. */ private static final String DELEGATING_CLASS_LOADER_NAME = "sun.reflect.DelegatingClassLoader"; /** * An index indicating the first element of a collection. */ private static final int ONLY = 0; /** * A dispatcher for extracting a class loader's loaded classes. */ private static final Dispatcher.Initializable DISPATCHER = doPrivileged(Dispatcher.CreationAction.INSTANCE); /** * Creates a class loading delegate for a delegating class loader. * * @param classLoader The delegating class loader. */ protected ForDelegatingClassLoader(ClassLoader classLoader) { super(classLoader); } /** * 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(); } /** * Checks if a class loader is a delegating class loader. * * @param classLoader The class loader to inspect or {@code null} to check the boot loader. * @return {@code true} if the class loader is a delegating class loader. */ protected static boolean isDelegating(@MaybeNull ClassLoader classLoader) { return classLoader != null && classLoader.getClass().getName().equals(DELEGATING_CLASS_LOADER_NAME); } /** * {@inheritDoc} */ public Class locate(String name) throws ClassNotFoundException { Vector> classes; try { classes = DISPATCHER.initialize().extract(classLoader); } catch (RuntimeException ignored) { return super.locate(name); } if (classes.size() != 1) { return super.locate(name); } Class type = classes.get(ONLY); return TypeDescription.ForLoadedType.getName(type).equals(name) ? type : super.locate(name); } /** * Representation of a Java {@link java.lang.reflect.Field}. */ protected interface Dispatcher { /** * Reads the classes of the represented collection. * * @param classLoader The class loader to read from. * @return The class loader's loaded classes. */ Vector> extract(ClassLoader classLoader); /** * An uninitialized version of a dispatcher for extracting a class loader's loaded classes. */ interface Initializable { /** * Initializes the dispatcher. * * @return An initialized dispatcher. */ Dispatcher initialize(); } /** * An action for creating a dispatcher. */ enum CreationAction implements PrivilegedAction { /** * The singleton instance. */ INSTANCE; /** * {@inheritDoc} */ public Initializable run() { try { return new Dispatcher.Resolved(ClassLoader.class.getDeclaredField("classes")); } catch (Exception exception) { return new Dispatcher.Unresolved(exception.getMessage()); } } } /** * Represents a field that could be located. */ @HashCodeAndEqualsPlugin.Enhance class Resolved implements Dispatcher, Initializable, PrivilegedAction { /** * The represented field. */ private final Field field; /** * Creates a new resolved field. * * @param field the represented field.l */ public Resolved(Field field) { this.field = field; } /** * 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 Dispatcher initialize() { return doPrivileged(this); } /** * {@inheritDoc} */ @SuppressWarnings("unchecked") public Vector> extract(ClassLoader classLoader) { try { return (Vector>) field.get(classLoader); } catch (IllegalAccessException exception) { throw new IllegalStateException("Cannot access field", exception); } } /** * {@inheritDoc} */ public Dispatcher run() { field.setAccessible(true); return this; } } /** * Represents a field that could not be located. */ @HashCodeAndEqualsPlugin.Enhance class Unresolved implements Initializable { /** * The reason why this dispatcher is unavailable. */ private final String message; /** * Creates a representation of a non-resolved field. * * @param message The reason why this dispatcher is unavailable. */ public Unresolved(String message) { this.message = message; } /** * {@inheritDoc} */ public Dispatcher initialize() { throw new UnsupportedOperationException("Could not locate classes vector: " + message); } } } } /** * A class loading delegate that allows the location of explicitly registered classes that cannot * be located by a class loader directly. This allows for locating classes that are loaded by * an anonymous class loader which does not register its classes in a system dictionary. */ @HashCodeAndEqualsPlugin.Enhance class Explicit implements ClassLoadingDelegate { /** * A class loading delegate that is queried for classes that are not registered explicitly. */ private final ClassLoadingDelegate fallbackDelegate; /** * The map of registered classes mapped by their name. */ private final Map> types; /** * Creates a new class loading delegate with a possibility of looking up explicitly * registered classes. * * @param classLoader The class loader to be used for looking up classes. * @param types A collection of classes that cannot be looked up explicitly. */ public Explicit(@MaybeNull ClassLoader classLoader, Collection> types) { this(Default.of(classLoader), types); } /** * Creates a new class loading delegate with a possibility of looking up explicitly * registered classes. * * @param fallbackDelegate The class loading delegate to query for any class that is not * registered explicitly. * @param types A collection of classes that cannot be looked up explicitly. */ public Explicit(ClassLoadingDelegate fallbackDelegate, Collection> types) { this.fallbackDelegate = fallbackDelegate; this.types = new HashMap>(); for (Class type : types) { this.types.put(TypeDescription.ForLoadedType.getName(type), type); } } /** * Creates an explicit class loading delegate for the given type. * * @param type The type that is explicitly locatable. * @return A suitable class loading delegate. */ public static ClassLoadingDelegate of(Class type) { return new Explicit(type.getClassLoader(), Collections.singleton(type)); } /** * {@inheritDoc} */ public Class locate(String name) throws ClassNotFoundException { Class type = types.get(name); return type == null ? fallbackDelegate.locate(name) : type; } /** * {@inheritDoc} */ @MaybeNull public ClassLoader getClassLoader() { return fallbackDelegate.getClassLoader(); } } } /** * A non-operational class file transformer that remembers the binary format of a given class. */ protected static class ExtractionClassFileTransformer implements ClassFileTransformer { /** * An indicator that an attempted class file transformation did not alter the handed class file. */ @AlwaysNull private static final byte[] DO_NOT_TRANSFORM = null; /** * The class loader that is expected to have loaded the looked-up a class. */ @MaybeNull private final ClassLoader classLoader; /** * The name of the type to look up. */ private final String typeName; /** * The binary representation of the looked-up class. */ @MaybeNull @SuppressFBWarnings(value = "VO_VOLATILE_REFERENCE_TO_ARRAY", justification = "The array is not to be modified by contract") private volatile byte[] binaryRepresentation; /** * Creates a class file transformer for the purpose of extraction. * * @param classLoader The class loader that is expected to have loaded the looked-up a class. * @param typeName The name of the type to look up. */ protected ExtractionClassFileTransformer(@MaybeNull ClassLoader classLoader, String typeName) { this.classLoader = classLoader; this.typeName = typeName; } /** * {@inheritDoc} */ @MaybeNull @SuppressFBWarnings(value = {"EI_EXPOSE_REP", "EI_EXPOSE_REP2"}, justification = "The array is not modified by class contract.") public byte[] transform(@MaybeNull ClassLoader classLoader, @MaybeNull String internalName, @MaybeNull Class redefinedType, ProtectionDomain protectionDomain, byte[] binaryRepresentation) { if (internalName != null && isChildOf(this.classLoader).matches(classLoader) && typeName.equals(internalName.replace('/', '.'))) { this.binaryRepresentation = binaryRepresentation.clone(); } return DO_NOT_TRANSFORM; } /** * Returns the binary representation of the class file that was looked up. The returned array must never be modified. * * @return The binary representation of the class file or {@code null} if no such class file could * be located. */ @MaybeNull @SuppressFBWarnings(value = "EI_EXPOSE_REP", justification = "The array is not to be modified by contract") protected byte[] getBinaryRepresentation() { return binaryRepresentation; } } } /** * A class file locator that discriminates by a type's package. */ @HashCodeAndEqualsPlugin.Enhance class PackageDiscriminating implements ClassFileLocator { /** * A mapping of package names to class file locators. */ private final Map classFileLocators; /** * Creates a new package-discriminating class file locator. * * @param classFileLocators A mapping of package names to class file locators where an empty string donates the default package. */ public PackageDiscriminating(Map classFileLocators) { this.classFileLocators = classFileLocators; } /** * {@inheritDoc} */ public Resolution locate(String name) throws IOException { int packageIndex = name.lastIndexOf('.'); ClassFileLocator classFileLocator = classFileLocators.get(packageIndex == -1 ? NamedElement.EMPTY_NAME : name.substring(0, packageIndex)); return classFileLocator == null ? new Resolution.Illegal(name) : classFileLocator.locate(name); } /** * {@inheritDoc} */ public void close() throws IOException { for (ClassFileLocator classFileLocator : classFileLocators.values()) { classFileLocator.close(); } } } /** * A class file locator that only applies for matched names. */ @HashCodeAndEqualsPlugin.Enhance class Filtering implements ClassFileLocator { /** * The matcher to determine if the delegate matcher is considered. */ private final ElementMatcher matcher; /** * The delegate class file locator. */ private final ClassFileLocator delegate; /** * Creates a new filtering class file locator. * * @param matcher The matcher to determine if the delegate matcher is considered. * @param delegate The delegate class file locator. */ public Filtering(ElementMatcher matcher, ClassFileLocator delegate) { this.matcher = matcher; this.delegate = delegate; } /** * {@inheritDoc} */ public Resolution locate(String name) throws IOException { return matcher.matches(name) ? delegate.locate(name) : new Resolution.Illegal(name); } /** * {@inheritDoc} */ public void close() throws IOException { delegate.close(); } } /** * A compound {@link ClassFileLocator} that chains several locators. * Any class file locator is queried in the supplied order until one locator is able to provide an input * stream of the class file. */ @HashCodeAndEqualsPlugin.Enhance class Compound implements ClassFileLocator, Closeable { /** * The {@link ClassFileLocator}s which are represented by this compound * class file locator in the order of their application. */ private final List classFileLocators; /** * Creates a new compound class file locator. * * @param classFileLocator The {@link ClassFileLocator}s to be * represented by this compound class file locator in the order of their application. */ public Compound(ClassFileLocator... classFileLocator) { this(Arrays.asList(classFileLocator)); } /** * Creates a new compound class file locator. * * @param classFileLocators The {@link ClassFileLocator}s to be represented by this compound class file locator in * the order of their application. */ public Compound(List classFileLocators) { this.classFileLocators = new ArrayList(); for (ClassFileLocator classFileLocator : classFileLocators) { if (classFileLocator instanceof Compound) { this.classFileLocators.addAll(((Compound) classFileLocator).classFileLocators); } else if (!(classFileLocator instanceof NoOp)) { this.classFileLocators.add(classFileLocator); } } } /** * {@inheritDoc} */ public Resolution locate(String name) throws IOException { for (ClassFileLocator classFileLocator : classFileLocators) { Resolution resolution = classFileLocator.locate(name); if (resolution.isResolved()) { return resolution; } } return new Resolution.Illegal(name); } /** * {@inheritDoc} */ public void close() throws IOException { for (ClassFileLocator classFileLocator : classFileLocators) { classFileLocator.close(); } } } }