Added in API level 27

Summary: Ctors | Methods | Protected Methods | Inherited Methods

DelegateLastClassLoader

public final class DelegateLastClassLoader
extends PathClassLoader

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

A ClassLoader implementation that implements a delegate last lookup policy. For every class or resource this loader is requested to load, the following lookup order is employed:

The boot classpath is always searched first
Then, the list of dex files associated with this classloaders's dexPath is searched.
Finally, this classloader will delegate to the specified parent.

Summary

Public constructors
`DelegateLastClassLoader(String dexPath, ClassLoader parent)` Equivalent to calling `DelegateLastClassLoader(java.lang.String, java.lang.String, java.lang.ClassLoader, boolean)` with `librarySearchPath = null, delegateResourceLoading = true`.
`DelegateLastClassLoader(String dexPath, String librarySearchPath, ClassLoader parent)` Equivalent to calling `DelegateLastClassLoader(java.lang.String, java.lang.String, java.lang.ClassLoader, boolean)` with `delegateResourceLoading = true`.
`DelegateLastClassLoader(String dexPath, String librarySearchPath, ClassLoader parent, boolean delegateResourceLoading)` Creates a `DelegateLastClassLoader` that operates on a given `dexPath` and a `librarySearchPath`.

Public methods
`URL`	`getResource(String name)` Finds the resource with the given name.
`Enumeration<URL>`	`getResources(String name)` Finds all the resources with the given name.

Protected methods
`Class<?>`	`loadClass(String name, boolean resolve)` Loads the class with the specified binary name.

Inherited methods

From class


        
          dalvik.system.BaseDexClassLoader

`Class<?>`	`findClass(String name)` Finds the class with the specified binary name.
`String`	`findLibrary(String name)` Returns the absolute path name of a native library.
`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)`
`String`	`toString()` Returns a string representation of the object.

From class


        
          java.lang.ClassLoader

`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 `Package`s 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.

From class


        
          java.lang.Object

`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

DelegateLastClassLoader

Added in API level 27

public DelegateLastClassLoader (String dexPath, 
                ClassLoader parent)

Equivalent to calling DelegateLastClassLoader(java.lang.String, java.lang.String, java.lang.ClassLoader, boolean) with librarySearchPath = null, delegateResourceLoading = true.

Parameters
`dexPath`	`String`
`parent`	`ClassLoader`

DelegateLastClassLoader

Added in API level 27

public DelegateLastClassLoader (String dexPath, 
                String librarySearchPath, 
                ClassLoader parent)

Equivalent to calling DelegateLastClassLoader(java.lang.String, java.lang.String, java.lang.ClassLoader, boolean) with delegateResourceLoading = true.

Parameters
`dexPath`	`String`
`librarySearchPath`	`String`
`parent`	`ClassLoader`

DelegateLastClassLoader

Added in API level 29

public DelegateLastClassLoader (String dexPath, 
                String librarySearchPath, 
                ClassLoader parent, 
                boolean delegateResourceLoading)

Creates a DelegateLastClassLoader that operates on a given dexPath and a librarySearchPath. The dexPath should consist of one or more of the following, separated by File.pathSeparator, which is ":" on Android.

JAR/ZIP/APK files, possibly containing a "classes.dex" file as well as arbitrary resources.
Raw ".dex" files (not inside a zip file).

Unlike PathClassLoader, this classloader will attempt to locate classes (or resources) using the following lookup order.

The boot classpath is always searched first.
Then, the list of dex files contained in dexPath is searched./li>
Lastly, this classloader will delegate to the specified parent.

Note that this is in contrast to other standard classloaders that follow the delegation model. In those classloaders, the parent is always searched first. librarySearchPath specifies one more directories containing native library files, separated by File.pathSeparator.

Parameters
`dexPath`	`String`: the list of jar/apk files containing classes and resources, delimited by `File.pathSeparator`, which defaults to `":"` on Android. This value cannot be `null`.
`librarySearchPath`	`String`: the list of directories containing native libraries, delimited by `File.pathSeparator`; may be `null`.
`parent`	`ClassLoader`: the parent class loader. May be `null` for the boot classloader.
`delegateResourceLoading`	`boolean`: whether to delegate resource loading to the parent if the resource is not found. This does not affect class loading delegation.

Public methods

getResource

Added in API level 27

public URL getResource (String name)

Finds the resource with the given name. A resource is some data (images, audio, text, etc) that can be accessed by class code in a way that is independent of the location of the code.

The name of a resource is a '/'-separated path name thatf identifies the resource.

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.

getResources

Added in API level 27

public Enumeration<URL> getResources (String name)

Finds all the resources with the given name. A resource is some data (images, audio, text, etc) that can be accessed by class code in a way that is independent of the location of the code.

The name of a resource is a /-separated path name that identifies the resource.

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.

Throws
`IOException`

Protected methods

loadClass

Added in API level 27

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

Loads the class with the specified binary name. The default implementation of this method searches for classes in the following order:

Invoke findLoadedClass(java.lang.String) to check if the class has already been loaded.
Invoke the loadClass method on the parent class loader. If the parent is null the class loader built into the virtual machine is used, instead.
Invoke the findClass(java.lang.String) method to find the class.

If the class was found using the above steps, and the resolve flag is true, this method will then invoke the resolveClass(java.lang.Class) method on the resulting Class object.

Subclasses of ClassLoader are encouraged to override findClass(java.lang.String), rather than this method.

Parameters
`name`	`String`: The binary name of the class
`resolve`	`boolean`: If `true` then resolve the class

Returns
`Class<?>`	The resulting `Class` object

Throws
`ClassNotFoundException`