net.bytebuddy.android

Class AndroidClassLoadingStrategy

java.lang.Object

net.bytebuddy.android.AndroidClassLoadingStrategy

All Implemented Interfaces:

net.bytebuddy.dynamic.ClassLoadingStrategy

public class AndroidClassLoadingStrategy
extends Object
implements net.bytebuddy.dynamic.ClassLoadingStrategy

A class loading strategy that allows to load a dynamically created class at the runtime of an Android application. For this, a 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 Context.getDir(String, int) with specifying Context.MODE_PRIVATE visibility for the created folder or by using the getCodeCacheDir directory which is exposed for Android API versions 21 or higher.

By default, this Android ClassLoadingStrategy uses the Android SDK's dex compiler in version 1.7 which requires the Java class files in version 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 This version is slightly outdated but newer versions are not available in Maven Central which is why this outdated version is included with this class loading strategy.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 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.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	AndroidClassLoadingStrategy.DexProcessor A dex processor is responsible for converting a collection of Java class files into a Android dex file.

Nested classes/interfaces inherited from interface net.bytebuddy.dynamic.ClassLoadingStrategy

net.bytebuddy.dynamic.ClassLoadingStrategy.Default, net.bytebuddy.dynamic.ClassLoadingStrategy.WithDefaultProtectionDomain

Constructor Summary

Constructors

Constructor and Description
AndroidClassLoadingStrategy(File privateDirectory) Creates a new Android class loading strategy that uses the given folder for storing classes.
AndroidClassLoadingStrategy(File privateDirectory, AndroidClassLoadingStrategy.DexProcessor dexProcessor) Creates a new Android class loading strategy that uses the given folder for storing classes.

Method Summary

Modifier and Type	Method and Description
Map<net.bytebuddy.instrumentation.type.TypeDescription,Class<?>>	load(ClassLoader classLoader, Map<net.bytebuddy.instrumentation.type.TypeDescription,byte[]> types)
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

AndroidClassLoadingStrategy

public AndroidClassLoadingStrategy(File privateDirectory)

Creates a new Android class loading strategy that uses the given folder for storing classes. The created class loading strategy makes use of the AndroidClassLoadingStrategy.DexProcessor.ForSdkCompiler which uses the Android SDK's dex compiler in version 1.7 which is automatically included with this strategy. Doing so, the dex compiler is applied with default options.

Parameters:

privateDirectory - A directory that is not shared with other applications to be used for storing generated classes and their processed forms.

AndroidClassLoadingStrategy

public AndroidClassLoadingStrategy(File privateDirectory,
                                   AndroidClassLoadingStrategy.DexProcessor dexProcessor)

Creates a new Android class loading strategy that uses the given folder for storing classes.

Parameters:

privateDirectory - A directory that is not shared with other applications to be used for storing generated classes and their processed forms.

dexProcessor - The dex processor to be used for creating a dex file out of Java files.

Method Detail

load

public Map<net.bytebuddy.instrumentation.type.TypeDescription,Class<?>> load(ClassLoader classLoader,
                                                                             Map<net.bytebuddy.instrumentation.type.TypeDescription,byte[]> types)

Specified by:

load in interface net.bytebuddy.dynamic.ClassLoadingStrategy

toString

public String toString()

Overrides:

toString in class Object