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Byte Buddy Android allows for limited support of code generation on an Android runtime.
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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.android;
import android.annotation.TargetApi;
import android.os.Build;
import com.android.dx.cf.direct.DirectClassFile;
import com.android.dx.cf.direct.StdAttributeFactory;
import com.android.dx.dex.DexOptions;
import com.android.dx.dex.cf.CfOptions;
import com.android.dx.dex.cf.CfTranslator;
import com.android.dx.dex.file.ClassDefItem;
import com.android.dx.dex.file.DexFile;
import dalvik.system.BaseDexClassLoader;
import dalvik.system.DexClassLoader;
import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
import net.bytebuddy.description.type.TypeDescription;
import net.bytebuddy.dynamic.loading.ClassLoadingStrategy;
import net.bytebuddy.utility.RandomString;
import net.bytebuddy.utility.nullability.AlwaysNull;
import net.bytebuddy.utility.nullability.MaybeNull;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.Writer;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.jar.JarEntry;
import java.util.jar.JarOutputStream;
import java.util.logging.Logger;
/**
*
* A class loading strategy that allows to load a dynamically created class at the runtime of an Android
* application. For this, a {@link dalvik.system.DexClassLoader} is used under the covers.
*
*
* This class loader requires to write files to the file system which are then processed by the Android VM. It is
* not permitted by Android's security checks to store these files in a shared folder where they could be
* manipulated by a third application what would break Android's sandbox model. An example for a forbidden storage
* would therefore be the external storage. Instead, the class loading application must either supply a designated
* directory, such as by creating a directory using {@code android.content.Context#getDir(String, int)} with specifying
* {@code android.content.Context#MODE_PRIVATE} visibility for the created folder or by using the
* {@code getCodeCacheDir} directory which is exposed for Android API versions 21 or higher.
*
*
* By default, this Android {@link net.bytebuddy.dynamic.loading.ClassLoadingStrategy} uses the Android SDK's dex compiler in
* version 1.7 which requires the Java class files in version {@link net.bytebuddy.ClassFileVersion#JAVA_V6} as
* its input. This version is slightly outdated but newer versions are not available in Maven Central which is why this
* outdated version is included with this class loading strategy. Newer version can however be easily adapted by
* implementing the methods of a {@link net.bytebuddy.android.AndroidClassLoadingStrategy.DexProcessor} to
* appropriately delegate to the newer dex compiler. In case that the dex compiler's API was not altered, it would
* even be sufficient to include the newer dex compiler to the Android application's build path while also excluding
* the version that ships with this class loading strategy. While most parts of the Android SDK's components are
* licensed under the Apache 2.0 license, please also note
* their terms and conditions.
*
*/
public abstract class AndroidClassLoadingStrategy implements ClassLoadingStrategy {
/**
* The name of the dex file that the {@link dalvik.system.DexClassLoader} expects to find inside of a jar file
* that is handed to it as its argument.
*/
private static final String DEX_CLASS_FILE = "classes.dex";
/**
* The file name extension of a jar file.
*/
private static final String JAR_FILE_EXTENSION = ".jar";
/**
* A value for a {@link dalvik.system.DexClassLoader} to indicate that the library path is empty.
*/
@AlwaysNull
private static final String EMPTY_LIBRARY_PATH = null;
/**
* A processor for files before adding them to a dex file.
*/
private static final FileProcessor FILE_PROCESSOR;
/*
* Resolves the file processor.
*/
static {
FileProcessor fileProcessor;
try {
fileProcessor = new FileProcessor.ForReadOnlyClassFile(
Class.forName("java.nio.file.Files").getMethod("setPosixFilePermissions",
Class.forName("java.nio.file.Path"),
Set.class),
File.class.getMethod("toPath"),
Collections.singleton(Class.forName("java.nio.file.attribute.PosixFilePermission")
.getMethod("valueOf", String.class)
.invoke(null, "OWNER_READ")));
} catch (Throwable ignored) {
fileProcessor = FileProcessor.Disabled.INSTANCE;
}
FILE_PROCESSOR = fileProcessor;
}
/**
* The dex creator to be used by this Android class loading strategy.
*/
private final DexProcessor dexProcessor;
/**
* A directory that is not shared with other applications to be used for storing generated classes and
* their processed forms.
*/
protected final File privateDirectory;
/**
* A generator for random string values.
*/
protected final RandomString randomString;
/**
* Creates a new Android class loading strategy that uses the given folder for storing classes. The directory is not cleared
* by Byte Buddy after the application terminates. This remains the responsibility of the user.
*
* @param privateDirectory A directory that is not shared with other applications to be used for storing
* generated classes and their processed forms.
* @param dexProcessor The dex processor to be used for creating a dex file out of Java files.
*/
protected AndroidClassLoadingStrategy(File privateDirectory, DexProcessor dexProcessor) {
if (!privateDirectory.isDirectory()) {
throw new IllegalArgumentException("Not a directory " + privateDirectory);
}
this.privateDirectory = privateDirectory;
this.dexProcessor = dexProcessor;
randomString = new RandomString();
}
/**
* {@inheritDoc}
*/
public Map> load(@MaybeNull ClassLoader classLoader, Map types) {
DexProcessor.Conversion conversion = dexProcessor.create();
for (Map.Entry entry : types.entrySet()) {
conversion.register(entry.getKey().getName(), entry.getValue());
}
File jar = new File(privateDirectory, randomString.nextString() + JAR_FILE_EXTENSION);
try {
if (!jar.createNewFile()) {
throw new IllegalStateException("Cannot create " + jar);
}
JarOutputStream outputStream = new JarOutputStream(new BufferedOutputStream(new FileOutputStream(jar)));
try {
outputStream.putNextEntry(new JarEntry(DEX_CLASS_FILE));
conversion.drainTo(outputStream);
outputStream.closeEntry();
} finally {
outputStream.close();
}
FILE_PROCESSOR.accept(jar);
return doLoad(classLoader, types.keySet(), jar);
} catch (IOException exception) {
throw new IllegalStateException("Cannot write to zip file " + jar, exception);
} finally {
if (!jar.delete()) {
Logger.getLogger("net.bytebuddy").warning("Could not delete " + jar);
}
}
}
/**
* Applies the actual class loading.
*
* @param classLoader The target class loader.
* @param typeDescriptions Descriptions of the loaded types.
* @param jar A jar file containing the supplied types as dex files.
* @return A mapping of all type descriptions to their loaded types.
* @throws IOException If an I/O exception occurs.
*/
protected abstract Map> doLoad(@MaybeNull ClassLoader classLoader, Set typeDescriptions, File jar) throws IOException;
/**
* A processor for files that are added to a dex file.
*/
protected interface FileProcessor {
/**
* Accepts a file for processing.
*
* @param file The file to process.
*/
void accept(File file);
/**
* A non-operational file processor.
*/
enum Disabled implements FileProcessor {
/**
* The singleton instance.
*/
INSTANCE;
/**
* {@inheritDoc}
*/
public void accept(File file) {
/* do nothing */
}
}
/**
* A file processor that marks a file as read-only.
*/
class ForReadOnlyClassFile implements FileProcessor {
/**
* The {@code java.nio.file.Files#setPosixFilePermissions} method.
*/
private final Method setPosixFilePermissions;
/**
* The {@code java.io.File#toPath} method.
*/
private final Method toPath;
/**
* The set of permissions to set.
*/
private final Set permissions;
/**
* Creates a new file processor for a read only file.
*
* @param setPosixFilePermissions The {@code java.nio.file.Files#setPosixFilePermissions} method.
* @param toPath The {@code java.io.File#toPath} method.
* @param permissions The set of {java.nio.file.attribute.FilePermission} to set.
*/
protected ForReadOnlyClassFile(Method setPosixFilePermissions, Method toPath, Set permissions) {
this.setPosixFilePermissions = setPosixFilePermissions;
this.toPath = toPath;
this.permissions = permissions;
}
/**
* {@inheritDoc}
*/
public void accept(File file) {
try {
setPosixFilePermissions.invoke(null, toPath.invoke(file), permissions);
} catch (IllegalAccessException exception) {
throw new IllegalStateException("Cannot access file system permissions", exception);
} catch (InvocationTargetException exception) {
if (!(exception.getTargetException() instanceof UnsupportedOperationException)) {
throw new IllegalStateException("Cannot invoke file system permissions method", exception.getTargetException());
}
}
}
}
}
/**
* A dex processor is responsible for converting a collection of Java class files into a Android dex file.
*/
public interface DexProcessor {
/**
* Creates a new conversion process which allows to store several Java class files in the created dex
* file before writing this dex file to a specified {@link java.io.OutputStream}.
*
* @return A mutable conversion process.
*/
Conversion create();
/**
* Represents an ongoing conversion of several Java class files into an Android dex file.
*/
interface Conversion {
/**
* Adds a Java class to the generated dex file.
*
* @param name The binary name of the Java class.
* @param binaryRepresentation The binary representation of this class.
*/
void register(String name, byte[] binaryRepresentation);
/**
* Writes an Android dex file containing all registered Java classes to the provided output stream.
*
* @param outputStream The output stream to write the generated dex file to.
* @throws IOException If an error occurs while writing the file.
*/
void drainTo(OutputStream outputStream) throws IOException;
}
/**
* An implementation of a dex processor based on the Android SDK's dx.jar with an API that is
* compatible to version 1.7.
*/
class ForSdkCompiler implements DexProcessor {
/**
* An API version for a DEX file that ensures compatibility to the underlying compiler.
*/
private static final int DEX_COMPATIBLE_API_VERSION = 13;
/**
* The dispatcher for translating a dex file.
*/
private static final Dispatcher DISPATCHER;
/*
* Resolves the dispatcher for class file translations.
*/
static {
Dispatcher dispatcher;
try {
Class dxContextType = Class.forName("com.android.dx.command.dexer.DxContext");
dispatcher = new Dispatcher.ForApi26LevelCompatibleVm(CfTranslator.class.getMethod("translate",
dxContextType,
DirectClassFile.class,
byte[].class,
CfOptions.class,
DexOptions.class,
DexFile.class), dxContextType.getConstructor());
} catch (Throwable ignored) {
try {
dispatcher = new Dispatcher.ForLegacyVm(CfTranslator.class.getMethod("translate",
DirectClassFile.class,
byte[].class,
CfOptions.class,
DexOptions.class,
DexFile.class), DexOptions.class.getField("minSdkVersion"));
} catch (Throwable suppressed) {
try {
dispatcher = new Dispatcher.ForLegacyVm(CfTranslator.class.getMethod("translate",
DirectClassFile.class,
byte[].class,
CfOptions.class,
DexOptions.class,
DexFile.class), DexOptions.class.getField("targetApiLevel"));
} catch (Throwable throwable) {
dispatcher = new Dispatcher.Unavailable(throwable.getMessage());
}
}
}
DISPATCHER = dispatcher;
}
/**
* Creates a default dex processor that ensures API version compatibility.
*
* @return A dex processor using an SDK compiler that ensures compatibility.
*/
protected static DexProcessor makeDefault() {
DexOptions dexOptions = new DexOptions();
DISPATCHER.setTargetApi(dexOptions, DEX_COMPATIBLE_API_VERSION);
return new ForSdkCompiler(dexOptions, new CfOptions());
}
/**
* The file name extension of a Java class file.
*/
private static final String CLASS_FILE_EXTENSION = ".class";
/**
* Indicates that a dex file should be written without providing a human readable output.
*/
@AlwaysNull
private static final Writer NO_PRINT_OUTPUT = null;
/**
* Indicates that the dex file creation should not be verbose.
*/
private static final boolean NOT_VERBOSE = false;
/**
* The dex file options to be applied when converting a Java class file.
*/
private final DexOptions dexFileOptions;
/**
* The dex compiler options to be applied when converting a Java class file.
*/
private final CfOptions dexCompilerOptions;
/**
* Creates a new Android SDK dex compiler-based dex processor.
*
* @param dexFileOptions The dex file options to apply.
* @param dexCompilerOptions The dex compiler options to apply.
*/
public ForSdkCompiler(DexOptions dexFileOptions, CfOptions dexCompilerOptions) {
this.dexFileOptions = dexFileOptions;
this.dexCompilerOptions = dexCompilerOptions;
}
/**
* {@inheritDoc}
*/
public DexProcessor.Conversion create() {
return new Conversion(new DexFile(dexFileOptions));
}
/**
* Represents a to-dex-file-conversion of a
* {@link net.bytebuddy.android.AndroidClassLoadingStrategy.DexProcessor.ForSdkCompiler}.
*/
protected class Conversion implements DexProcessor.Conversion {
/**
* Indicates non-strict parsing of a class file.
*/
private static final boolean NON_STRICT = false;
/**
* The dex file that is created by this conversion.
*/
private final DexFile dexFile;
/**
* Creates a new ongoing to-dex-file conversion.
*
* @param dexFile The dex file that is created by this conversion.
*/
protected Conversion(DexFile dexFile) {
this.dexFile = dexFile;
}
/**
* {@inheritDoc}
*/
public void register(String name, byte[] binaryRepresentation) {
DirectClassFile directClassFile = new DirectClassFile(binaryRepresentation,
name.replace('.', '/') + CLASS_FILE_EXTENSION,
NON_STRICT);
directClassFile.setAttributeFactory(new StdAttributeFactory());
dexFile.add(DISPATCHER.translate(directClassFile,
binaryRepresentation,
dexCompilerOptions,
dexFileOptions,
new DexFile(dexFileOptions)));
}
/**
* {@inheritDoc}
*/
public void drainTo(OutputStream outputStream) throws IOException {
dexFile.writeTo(outputStream, NO_PRINT_OUTPUT, NOT_VERBOSE);
}
}
/**
* A dispatcher for translating a direct class file.
*/
protected interface Dispatcher {
/**
* Creates a new class file definition.
*
* @param directClassFile The direct class file to translate.
* @param binaryRepresentation The file's binary representation.
* @param dexCompilerOptions The dex compiler options.
* @param dexFileOptions The dex file options.
* @param dexFile The dex file.
* @return The translated class file definition.
*/
ClassDefItem translate(DirectClassFile directClassFile,
byte[] binaryRepresentation,
CfOptions dexCompilerOptions,
DexOptions dexFileOptions,
DexFile dexFile);
/**
* Sets the target API level if available.
*
* @param dexOptions The dex options to set the api version for
* @param targetApiLevel The target API level.
*/
void setTargetApi(DexOptions dexOptions, int targetApiLevel);
/**
* An unavailable dispatcher.
*/
class Unavailable implements Dispatcher {
/**
* A message explaining why the dispatcher is unavailable.
*/
private final String message;
/**
* Creates a new unavailable dispatcher.
*
* @param message A message explaining why the dispatcher is unavailable.
*/
protected Unavailable(String message) {
this.message = message;
}
/**
* {@inheritDoc}
*/
public ClassDefItem translate(DirectClassFile directClassFile,
byte[] binaryRepresentation,
CfOptions dexCompilerOptions,
DexOptions dexFileOptions,
DexFile dexFile) {
throw new IllegalStateException("Could not resolve dispatcher: " + message);
}
/**
* {@inheritDoc}
*/
public void setTargetApi(DexOptions dexOptions, int targetApiLevel) {
throw new IllegalStateException("Could not resolve dispatcher: " + message);
}
}
/**
* A dispatcher for a lagacy Android VM.
*/
class ForLegacyVm implements Dispatcher {
/**
* The {@code CfTranslator#translate(DirectClassFile, byte[], CfOptions, DexOptions, DexFile)} method.
*/
private final Method translate;
/**
* The {@code DexOptions#targetApiLevel} field.
*/
private final Field targetApi;
/**
* Creates a new dispatcher.
*
* @param translate The {@code CfTranslator#translate(DirectClassFile, byte[], CfOptions, DexOptions, DexFile)} method.
* @param targetApi The {@code DexOptions#targetApiLevel} field.
*/
protected ForLegacyVm(Method translate, Field targetApi) {
this.translate = translate;
this.targetApi = targetApi;
}
/**
* {@inheritDoc}
*/
public ClassDefItem translate(DirectClassFile directClassFile,
byte[] binaryRepresentation,
CfOptions dexCompilerOptions,
DexOptions dexFileOptions,
DexFile dexFile) {
try {
return (ClassDefItem) translate.invoke(null,
directClassFile,
binaryRepresentation,
dexCompilerOptions,
dexFileOptions,
dexFile);
} catch (IllegalAccessException exception) {
throw new IllegalStateException("Cannot access an Android dex file translation method", exception);
} catch (InvocationTargetException exception) {
throw new IllegalStateException("Cannot invoke Android dex file translation method", exception.getTargetException());
}
}
/**
* {@inheritDoc}
*/
public void setTargetApi(DexOptions dexOptions, int targetApiLevel) {
try {
targetApi.set(dexOptions, targetApiLevel);
} catch (IllegalAccessException exception) {
throw new IllegalStateException("Cannot access an Android dex file translation method", exception);
}
}
}
/**
* A dispatcher for an Android VM with API level 26 or higher.
*/
class ForApi26LevelCompatibleVm implements Dispatcher {
/**
* The {@code CfTranslator#translate(DxContext, DirectClassFile, byte[], CfOptions, DexOptions, DexFile)} method.
*/
private final Method translate;
/**
* The {@code com.android.dx.command.dexer.DxContext#DxContext()} constructor.
*/
private final Constructor dxContext;
/**
* Creates a new dispatcher.
*
* @param translate The {@code CfTranslator#translate(DxContext, DirectClassFile, byte[], CfOptions, DexOptions, DexFile)} method.
* @param dxContext The {@code com.android.dx.command.dexer.DxContext#DxContext()} constructor.
*/
protected ForApi26LevelCompatibleVm(Method translate, Constructor dxContext) {
this.translate = translate;
this.dxContext = dxContext;
}
/**
* {@inheritDoc}
*/
public ClassDefItem translate(DirectClassFile directClassFile,
byte[] binaryRepresentation,
CfOptions dexCompilerOptions,
DexOptions dexFileOptions,
DexFile dexFile) {
try {
return (ClassDefItem) translate.invoke(null,
dxContext.newInstance(),
directClassFile,
binaryRepresentation,
dexCompilerOptions,
dexFileOptions,
dexFile);
} catch (IllegalAccessException exception) {
throw new IllegalStateException("Cannot access an Android dex file translation method", exception);
} catch (InstantiationException exception) {
throw new IllegalStateException("Cannot instantiate dex context", exception);
} catch (InvocationTargetException exception) {
throw new IllegalStateException("Cannot invoke Android dex file translation method", exception.getTargetException());
}
}
/**
* {@inheritDoc}
*/
public void setTargetApi(DexOptions dexOptions, int targetApiLevel) {
/* do nothing */
}
}
}
}
}
/**
* An Android class loading strategy that creates a wrapper class loader that loads any type.
*/
@TargetApi(Build.VERSION_CODES.CUPCAKE)
public static class Wrapping extends AndroidClassLoadingStrategy {
/**
* Creates a new wrapping class loading strategy for Android that uses the default SDK-compiler based dex processor.
*
* @param privateDirectory A directory that is not shared with other applications to be used for storing
* generated classes and their processed forms.
*/
public Wrapping(File privateDirectory) {
this(privateDirectory, DexProcessor.ForSdkCompiler.makeDefault());
}
/**
* Creates a new wrapping class loading strategy for Android.
*
* @param privateDirectory A directory that is not shared with other applications to be used for storing
* generated classes and their processed forms.
* @param dexProcessor The dex processor to be used for creating a dex file out of Java files.
*/
public Wrapping(File privateDirectory, DexProcessor dexProcessor) {
super(privateDirectory, dexProcessor);
}
/**
* {@inheritDoc}
*/
@SuppressFBWarnings(value = "DP_CREATE_CLASSLOADER_INSIDE_DO_PRIVILEGED", justification = "Android discourages the use of access controllers")
protected Map> doLoad(@MaybeNull ClassLoader classLoader, Set typeDescriptions, File jar) {
ClassLoader dexClassLoader = new DexClassLoader(jar.getAbsolutePath(), privateDirectory.getAbsolutePath(), EMPTY_LIBRARY_PATH, classLoader);
Map> loadedTypes = new HashMap>();
for (TypeDescription typeDescription : typeDescriptions) {
try {
loadedTypes.put(typeDescription, Class.forName(typeDescription.getName(), false, dexClassLoader));
} catch (ClassNotFoundException exception) {
throw new IllegalStateException("Cannot load " + typeDescription, exception);
}
}
return loadedTypes;
}
}
/**
* An Android class loading strategy that injects types into the target class loader.
*/
@TargetApi(Build.VERSION_CODES.CUPCAKE)
public static class Injecting extends AndroidClassLoadingStrategy {
/**
* The dispatcher to use for loading a dex file.
*/
private static final Dispatcher DISPATCHER;
/*
* Creates a dispatcher to use for loading a dex file.
*/
static {
Dispatcher dispatcher;
try {
dispatcher = new Dispatcher.ForAndroidPVm(BaseDexClassLoader.class.getMethod("addDexPath", String.class, boolean.class));
} catch (Throwable ignored) {
dispatcher = Dispatcher.ForLegacyVm.INSTANCE;
}
DISPATCHER = dispatcher;
}
/**
* Creates a new injecting class loading strategy for Android that uses the default SDK-compiler based dex processor.
*
* @param privateDirectory A directory that is not shared with other applications to be used for storing
* generated classes and their processed forms.
*/
public Injecting(File privateDirectory) {
this(privateDirectory, DexProcessor.ForSdkCompiler.makeDefault());
}
/**
* Creates a new injecting class loading strategy for Android.
*
* @param privateDirectory A directory that is not shared with other applications to be used for storing
* generated classes and their processed forms.
* @param dexProcessor The dex processor to be used for creating a dex file out of Java files.
*/
public Injecting(File privateDirectory, DexProcessor dexProcessor) {
super(privateDirectory, dexProcessor);
}
/**
* {@inheritDoc}
*/
public Map> load(@MaybeNull ClassLoader classLoader, Map types) {
if (classLoader == null) {
throw new IllegalArgumentException("Cannot inject classes into the bootstrap class loader on Android");
}
return super.load(classLoader, types);
}
/**
* {@inheritDoc}
*/
protected Map> doLoad(@MaybeNull ClassLoader classLoader, Set typeDescriptions, File jar) throws IOException {
dalvik.system.DexFile dexFile = DISPATCHER.loadDex(privateDirectory, jar, classLoader, randomString);
try {
Map> loadedTypes = new HashMap>();
for (TypeDescription typeDescription : typeDescriptions) {
synchronized (classLoader) { // Guaranteed to be non-null by check in 'load' method.
Class type = DISPATCHER.loadClass(dexFile, classLoader, typeDescription);
if (type == null) {
throw new IllegalStateException("Could not load " + typeDescription);
}
loadedTypes.put(typeDescription, type);
}
}
return loadedTypes;
} finally {
if (dexFile != null) {
dexFile.close();
}
}
}
/**
* A dispatcher for loading a dex file.
*/
protected interface Dispatcher {
/**
* Loads a dex file.
*
* @param privateDirectory The private directory to use if required.
* @param jar The jar to load.
* @param classLoader The class loader to inject into.
* @param randomString The random string to use.
* @return The created {@link dalvik.system.DexFile} or {@code null} if no such file is created.
* @throws IOException If an I/O exception is thrown.
*/
@MaybeNull
dalvik.system.DexFile loadDex(File privateDirectory, File jar, @MaybeNull ClassLoader classLoader, RandomString randomString) throws IOException;
/**
* Loads a class.
*
* @param dexFile The dex file to process if any was created.
* @param classLoader The class loader to load the class from.
* @param typeDescription The type to load.
* @return The loaded class.
*/
@MaybeNull
Class loadClass(dalvik.system.DexFile dexFile, @MaybeNull ClassLoader classLoader, TypeDescription typeDescription);
/**
* A dispatcher for legacy VMs that allow {@link dalvik.system.DexFile#loadDex(String, String, int)}.
*/
enum ForLegacyVm implements Dispatcher {
/**
* The singleton instance.
*/
INSTANCE;
/**
* A constant indicating the use of no flags.
*/
private static final int NO_FLAGS = 0;
/**
* A file extension used for holding Android's optimized data.
*/
private static final String EXTENSION = ".data";
/**
* {@inheritDoc}
*/
@MaybeNull
public dalvik.system.DexFile loadDex(File privateDirectory,
File jar,
@MaybeNull ClassLoader classLoader,
RandomString randomString) throws IOException {
return dalvik.system.DexFile.loadDex(jar.getAbsolutePath(),
new File(privateDirectory.getAbsolutePath(), randomString.nextString() + EXTENSION).getAbsolutePath(),
NO_FLAGS);
}
/**
* {@inheritDoc}
*/
@MaybeNull
public Class loadClass(dalvik.system.DexFile dexFile, @MaybeNull ClassLoader classLoader, TypeDescription typeDescription) {
return dexFile.loadClass(typeDescription.getName(), classLoader);
}
}
/**
* A dispatcher for an Android P VM that uses the reflection-only method {@code addDexPath} of {@link DexClassLoader}.
*/
class ForAndroidPVm implements Dispatcher {
/**
* Indicates that this dispatcher does not return a {@link dalvik.system.DexFile} instance.
*/
@AlwaysNull
private static final dalvik.system.DexFile NO_RETURN_VALUE = null;
/**
* The {@code BaseDexClassLoader#addDexPath(String, boolean)} method.
*/
private final Method addDexPath;
/**
* Creates a new Android P-compatible dispatcher for loading a dex file.
*
* @param addDexPath The {@code BaseDexClassLoader#addDexPath(String, boolean)} method.
*/
protected ForAndroidPVm(Method addDexPath) {
this.addDexPath = addDexPath;
}
/**
* {@inheritDoc}
*/
@MaybeNull
public dalvik.system.DexFile loadDex(File privateDirectory,
File jar,
@MaybeNull ClassLoader classLoader,
RandomString randomString) throws IOException {
if (!(classLoader instanceof BaseDexClassLoader)) {
throw new IllegalArgumentException("On Android P, a class injection can only be applied to BaseDexClassLoader: " + classLoader);
}
try {
addDexPath.invoke(classLoader, jar.getAbsolutePath(), false);
return NO_RETURN_VALUE;
} catch (IllegalAccessException exception) {
throw new IllegalStateException("Cannot access BaseDexClassLoader#addDexPath(String, boolean)", exception);
} catch (InvocationTargetException exception) {
Throwable cause = exception.getTargetException();
if (cause instanceof IOException) {
throw (IOException) cause;
} else {
throw new IllegalStateException("Cannot invoke BaseDexClassLoader#addDexPath(String, boolean)", cause);
}
}
}
/**
* {@inheritDoc}
*/
public Class loadClass(@MaybeNull dalvik.system.DexFile dexFile, @MaybeNull ClassLoader classLoader, TypeDescription typeDescription) {
try {
return Class.forName(typeDescription.getName(), false, classLoader);
} catch (ClassNotFoundException exception) {
throw new IllegalStateException("Could not locate " + typeDescription, exception);
}
}
}
}
}
}