BaseDexClassLoader - Android SDK

Classes

Summary: Ctors | Methods | Protected Methods | Inherited Methods | [Expand All]

Added in API level 14

public class

BaseDexClassLoader

extends ClassLoader

java.lang.Object
↳	java.lang.ClassLoader
	↳	dalvik.system.BaseDexClassLoader

Known Direct Subclasses

DexClassLoader, PathClassLoader

Class Overview

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

Summary

Public Constructors
	BaseDexClassLoader(String dexPath, File optimizedDirectory, String libraryPath, ClassLoader parent) Constructs an instance.

Public Methods
String	findLibrary(String name) Returns the absolute path of the native library with the specified name, or `null`.
String	toString() Returns a string containing a concise, human-readable description of this object.

Protected Methods
Class<?>	findClass(String name) Overridden by subclasses, throws a `ClassNotFoundException` by default.
URL	findResource(String name) Finds the URL of the resource with the specified name.
Enumeration<URL>	findResources(String name) Finds an enumeration of URLs for the resource with the specified name.
synchronized Package	getPackage(String name) Returns package information for the given package.

[Expand]

Inherited Methods

From class java.lang.ClassLoader

void	clearAssertionStatus() Sets the default assertion status for this class loader to `false` and removes any package default and class assertion status settings.
final Class<?>	defineClass(String name, ByteBuffer b, ProtectionDomain protectionDomain) Defines a new class with the specified name, byte code from the byte buffer and the optional protection domain.
final Class<?>	defineClass(String className, byte[] classRep, int offset, int length, ProtectionDomain protectionDomain) Constructs a new class from an array of bytes containing a class definition in class file format and assigns the specified protection domain to the new class.
final Class<?>	defineClass(String className, byte[] classRep, int offset, int length) Constructs a new class from an array of bytes containing a class definition in class file format.
final Class<?>	defineClass(byte[] classRep, int offset, int length) This method was deprecated in API level 1. Use `defineClass(String, byte[], int, int)`
Package	definePackage(String name, String specTitle, String specVersion, String specVendor, String implTitle, String implVersion, String implVendor, URL sealBase) Defines and returns a new `Package` using the specified information.
Class<?>	findClass(String className) Overridden by subclasses, throws a `ClassNotFoundException` by default.
String	findLibrary(String libName) Returns the absolute path of the native library with the specified name, or `null`.
final Class<?>	findLoadedClass(String className) Returns the class with the specified name if it has already been loaded by the VM or `null` if it has not yet been loaded.
URL	findResource(String resName) Finds the URL of the resource with the specified name.
Enumeration<URL>	findResources(String resName) Finds an enumeration of URLs for the resource with the specified name.
final Class<?>	findSystemClass(String className) Finds the class with the specified name, loading it using the system class loader if necessary.
Package	getPackage(String name) Returns the package with the specified name.
Package[]	getPackages() Returns all the packages known to this class loader.
final ClassLoader	getParent() Returns this class loader's parent.
URL	getResource(String resName) Returns the URL of the resource with the specified name.
InputStream	getResourceAsStream(String resName) Returns a stream for the resource with the specified name.
Enumeration<URL>	getResources(String resName) Returns an enumeration of URLs for the resource with the specified name.
static ClassLoader	getSystemClassLoader() Returns the system class loader.
static URL	getSystemResource(String resName) Finds the URL of the resource with the specified name.
static InputStream	getSystemResourceAsStream(String resName) Returns a stream for the resource with the specified name.
static Enumeration<URL>	getSystemResources(String resName) Returns an enumeration of URLs for the resource with the specified name.
Class<?>	loadClass(String className, boolean resolve) Loads the class with the specified name, optionally linking it after loading.
Class<?>	loadClass(String className) Loads the class with the specified name.
final void	resolveClass(Class<?> clazz) Forces a class to be linked (initialized).
void	setClassAssertionStatus(String cname, boolean enable) Sets the assertion status of the class with the specified name.
void	setDefaultAssertionStatus(boolean enable) Sets the default assertion status for this class loader.
void	setPackageAssertionStatus(String pname, boolean enable) Sets the assertion status of the package with the specified name.
final void	setSigners(Class<?> c, Object[] signers) Sets the signers of the specified class.

From class java.lang.Object

Object	clone() Creates and returns a copy of this `Object`.
boolean	equals(Object o) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of `Class` that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait() Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object.
final void	wait(long millis, int nanos) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.
final void	wait(long millis) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.

Public Constructors

public BaseDexClassLoader (String dexPath, File optimizedDirectory, String libraryPath, ClassLoader parent)

Added in API level 14

Constructs an instance.

Parameters

dexPath	the list of jar/apk files containing classes and resources, delimited by `File.pathSeparator`, which defaults to `":"` on Android
optimizedDirectory	directory where optimized dex files should be written; may be `null`
libraryPath	the list of directories containing native libraries, delimited by `File.pathSeparator`; may be `null`
parent	the parent class loader

Public Methods

public String findLibrary (String name)

Added in API level 1

Returns the absolute path of the native library with the specified name, or null. If this method returns null then the virtual machine searches the directories specified by the system property "java.library.path".

This implementation always returns null.

Parameters

name	the name of the library to find.

Returns

the absolute path of the library.

public String toString ()

Added in API level 1

Returns a string containing a concise, human-readable description of this object. Subclasses are encouraged to override this method and provide an implementation that takes into account the object's type and data. The default implementation is equivalent to the following expression:

   getClass().getName() + '@' + Integer.toHexString(hashCode())

See Writing a useful toString method if you intend implementing your own toString method.

Returns

a printable representation of this object.

Protected Methods

protected Class<?> findClass (String name)

Added in API level 1

Overridden by subclasses, throws a ClassNotFoundException by default. This method is called by loadClass after the parent ClassLoader has failed to find a loaded class of the same name.

Parameters

name	the name of the class to look for.

Returns

the Class object that is found.

Throws

ClassNotFoundException

protected URL findResource (String name)

Added in API level 1

Finds the URL of the resource with the specified name. This implementation just returns null; it should be overridden in subclasses.

Parameters

name	the name of the resource to find.

Returns

the URL object for the requested resource.

protected Enumeration<URL> findResources (String name)

Added in API level 1

Finds an enumeration of URLs for the resource with the specified name. This implementation just returns an empty Enumeration; it should be overridden in subclasses.

Parameters

name	the name of the resource to find.

Returns

an enumeration of URL objects for the requested resource.

protected synchronized Package getPackage (String name)

Added in API level 1

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 dummy 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	the name of the class

Returns

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

Results

Classes

BaseDexClassLoader

Class Overview

Summary

Public Constructors

public BaseDexClassLoader (String dexPath, File optimizedDirectory, String libraryPath, ClassLoader parent)

Parameters

Public Methods

public String findLibrary (String name)

Parameters

Returns

public String toString ()

Returns

Protected Methods

protected Class<?> findClass (String name)

Parameters

Returns

Throws

protected URL findResource (String name)

Parameters

Returns

protected Enumeration<URL> findResources (String name)

Parameters

Returns

protected synchronized Package getPackage (String name)

Parameters

Returns