BaseDexClassLoader

public class BaseDexClassLoader
extends ClassLoader

java.lang.Object
   ↳ java.lang.ClassLoader
     ↳ dalvik.system.BaseDexClassLoader
DexClassLoader A class loader that loads classes from .jar and .apk files containing a classes.dex entry. 
InMemoryDexClassLoader A ClassLoader implementation that loads classes from a buffer containing a DEX file. 
PathClassLoader Provides a simple ClassLoader implementation that operates on a list of files and directories in the local file system, but does not attempt to load classes from the network. 
DelegateLastClassLoader A ClassLoader implementation that implements a delegate last lookup policy. 


Base class for common functionality between various dex-based ClassLoader implementations.

Summary

Public constructors

BaseDexClassLoader(String dexPath, File optimizedDirectory, String librarySearchPath, ClassLoader parent)

Constructs an instance.

Public methods

String findLibrary(String name)

Returns the absolute path name of a native library.

String toString()

Returns a string representation of the object.

Protected methods

Class<?> findClass(String name)

Finds the class with the specified binary name.

URL findResource(String name)

Finds the resource with the given name.

Enumeration<URL> findResources(String name)

Returns an enumeration of URL objects representing all the resources with the given name.

Package getPackage(String name)

This method is deprecated. See ClassLoader.getPackage(String)

Inherited methods

void clearAssertionStatus()

Sets the default assertion status for this class loader to false and discards any package defaults or class assertion status settings associated with the class loader.

final Class<?> defineClass(String name, byte[] b, int off, int len, ProtectionDomain protectionDomain)

Converts an array of bytes into an instance of class Class, with a given ProtectionDomain.

final Class<?> defineClass(String name, ByteBuffer b, ProtectionDomain protectionDomain)

Converts a ByteBuffer into an instance of class Class, with the given ProtectionDomain.

final Class<?> defineClass(byte[] b, int off, int len)

This method was deprecated in API level 15. Replaced by defineClass(String, byte[], int, int)

final Class<?> defineClass(String name, byte[] b, int off, int len)

Converts an array of bytes into an instance of class Class.

Package definePackage(String name, String specTitle, String specVersion, String specVendor, String implTitle, String implVersion, String implVendor, URL sealBase)

Defines a package by name in this ClassLoader.

Class<?> findClass(String name)

Finds the class with the specified binary name.

String findLibrary(String libname)

Returns the absolute path name of a native library.

final Class<?> findLoadedClass(String name)

Returns the class with the given binary name if this loader has been recorded by the Java virtual machine as an initiating loader of a class with that binary name.

URL findResource(String name)

Finds the resource with the given name.

Enumeration<URL> findResources(String name)

Returns an enumeration of URL objects representing all the resources with the given name.

final Class<?> findSystemClass(String name)

Finds a class with the specified binary name, loading it if necessary.

Package getPackage(String name)

This method was deprecated in API level 35. If multiple class loaders delegate to each other and define classes with the same package name, and one such loader relies on the lookup behavior of getPackage to return a Package from a parent loader, then the properties exposed by the Package may not be as expected in the rest of the program. For example, the Package will only expose annotations from the package-info.class file defined by the parent loader, even if annotations exist in a package-info.class file defined by a child loader.

Package[] getPackages()

Returns all of the Packages that have been defined by this class loader and its ancestors.

final ClassLoader getParent()

Returns the parent class loader for delegation.

URL getResource(String name)

Finds the resource with the given name.

InputStream getResourceAsStream(String name)

Returns an input stream for reading the specified resource.

Enumeration<URL> getResources(String name)

Finds all the resources with the given name.

static ClassLoader getSystemClassLoader()

Returns the system class loader.

static URL getSystemResource(String name)

Find a resource of the specified name from the search path used to load classes.

static InputStream getSystemResourceAsStream(String name)

Open for reading, a resource of the specified name from the search path used to load classes.

static Enumeration<URL> getSystemResources(String name)

Finds all resources of the specified name from the search path used to load classes.

Class<?> loadClass(String name, boolean resolve)

Loads the class with the specified binary name.

Class<?> loadClass(String name)

Loads the class with the specified binary name.

static boolean registerAsParallelCapable()

Registers the caller as #isRegisteredAsParallelCapable() parallel capable.

final void resolveClass(Class<?> c)

Links the specified class.

void setClassAssertionStatus(String className, boolean enabled)

Sets the desired assertion status for the named top-level class in this class loader and any nested classes contained therein.

void setDefaultAssertionStatus(boolean enabled)

Sets the default assertion status for this class loader.

void setPackageAssertionStatus(String packageName, boolean enabled)

Sets the package default assertion status for the named package.

final void setSigners(Class<?> c, Object[] signers)

Sets the signers of a class.

Object clone()

Creates and returns a copy of this object.

boolean equals(Object obj)

Indicates whether some other object is "equal to" this one.

void finalize()

Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.

final Class<?> getClass()

Returns the runtime class of this Object.

int hashCode()

Returns a hash code value for the object.

final void notify()

Wakes up a single thread that is waiting on this object's monitor.

final void notifyAll()

Wakes up all threads that are waiting on this object's monitor.

String toString()

Returns a string representation of the object.

final void wait(long timeoutMillis, int nanos)

Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

final void wait(long timeoutMillis)

Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

final void wait()

Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

Public constructors

BaseDexClassLoader

Added in API level 14
public BaseDexClassLoader (String dexPath, 
                File optimizedDirectory, 
                String librarySearchPath, 
                ClassLoader parent)

Constructs an instance. Note that all the *.jar and *.apk files from dexPath might be first extracted in-memory before the code is loaded. This can be avoided by passing raw dex files (*.dex) in the dexPath.

Parameters
dexPath String: the list of jar/apk files containing classes and resources, delimited by File.pathSeparator, which defaults to ":" on Android.

optimizedDirectory File: this parameter is deprecated and has no effect since API level 26.

librarySearchPath String: the list of directories containing native libraries, delimited by File.pathSeparator; may be null

parent ClassLoader: the parent class loader

Public methods

findLibrary

Added in API level 14
public String findLibrary (String name)

Returns the absolute path name of a native library. The VM invokes this method to locate the native libraries that belong to classes loaded with this class loader. If this method returns null, the VM searches the library along the path specified as the "java.library.path" property.

Parameters
name String: The library name

Returns
String The absolute path of the native library

toString

Added in API level 14
public String toString ()

Returns a string representation of the object.

Returns
String a string representation of the object.

Protected methods

findClass

Added in API level 14
protected Class<?> findClass (String name)

Finds the class with the specified binary name. This method should be overridden by class loader implementations that follow the delegation model for loading classes, and will be invoked by the loadClass method after checking the parent class loader for the requested class.

Parameters
name String: The binary name of the class

Returns
Class<?> The resulting Class object

findResource

Added in API level 14
protected URL findResource (String name)

Finds the resource with the given name. Class loader implementations should override this method.

Parameters
name String: The resource name

Returns
URL URL object for reading the resource; null if the resource could not be found, a URL could not be constructed to locate the resource, the resource is in a package that is not opened unconditionally, or access to the resource is denied by the security manager.

findResources

Added in API level 14
protected Enumeration<URL> findResources (String name)

Returns an enumeration of URL objects representing all the resources with the given name. Class loader implementations should override this method.

Parameters
name String: The resource name

Returns
Enumeration<URL> An enumeration of URL objects for the resource. If no resources could be found, the enumeration will be empty. Resources for which a URL cannot be constructed, are in a package that is not opened unconditionally, or access to the resource is denied by the security manager, are not returned in the enumeration.

getPackage

Added in API level 14
protected Package getPackage (String name)

This method is deprecated.
See ClassLoader.getPackage(String)

Returns package information for the given package. Unfortunately, instances of this class don't really have this information, and as a non-secure ClassLoader, it isn't even required to, according to the spec. Yet, we want to provide it, in order to make all those hopeful callers of myClass.getPackage().getName() happy. Thus we construct a Package object the first time it is being requested and fill most of the fields with fake values. The Package object is then put into the ClassLoader's package cache, so we see the same one next time. We don't create Package objects for null arguments or for the default package.

There is a limited chance that we end up with multiple Package objects representing the same package: It can happen when when a package is scattered across different JAR files which were loaded by different ClassLoader instances. This is rather unlikely, and given that this whole thing is more or less a workaround, probably not worth the effort to address.

Parameters
name String: the name of the class

Returns
Package the package information for the class, or null if there is no package information available for it