Package java.lang

Class ClassLoader

java.lang.Object

java.lang.ClassLoader

Direct Known Subclasses:

URLClassLoader

public class ClassLoader
extends Object

This stripped down ClassLoader class is simply here to give us cross-platform support for code that might need a valid classloader.

xapi-gwt-reflect does call into the one and only system classloader, to define mappings of java-names to runtime classes, in order to enable Class.forName() and ClassLoader.loadClass();

Author:

"James X. Nelson (james@wetheinter.net)"

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	ClassLoader()	Creates a new class loader using the ClassLoader returned by the method getSystemClassLoader() as the parent class loader.
protected	ClassLoader(ClassLoader parent)	Creates a new class loader using the specified parent class loader for delegation.

Method Summary

Modifier and Type	Method	Description
protected Class<?>	findClass(String name)	Finds the class with the specified binary name.
protected Class<?>	findSystemClass(String name)	Finds a class with the specified binary name, loading it if necessary.
ClassLoader	getParent()	Returns the parent class loader for delegation.
URL	getResource(String name)
InputStream	getResourceAsStream(String name)	Unsupported.
static ClassLoader	getSystemClassLoader()	get system class loader.
static InputStream	getSystemResourceAsStream(String name)	Unsupported.
Class<?>	loadClass(String name)	Loads the class with the specified binary name.
protected Class<?>	loadClass(String name, boolean resolve)	Loads the class with the specified binary name.
protected void	setSigners(Class<?> pclass, Object[] signers)	No-op for compatibility.

Methods inherited from class java.lang.Object

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

Constructor Detail

ClassLoader

protected ClassLoader(ClassLoader parent)

Creates a new class loader using the specified parent class loader for delegation.

Parameters:

parent - The parent class loader

ClassLoader

protected ClassLoader()

Creates a new class loader using the ClassLoader returned by the method getSystemClassLoader() as the parent class loader.

Method Detail

loadClass

public Class<?> loadClass(String name)
                   throws ClassNotFoundException

Loads the class with the specified binary name. This method searches for classes in the same manner as the loadClass(String, boolean) method. It is invoked by the Java virtual machine to resolve class references. Invoking this method is equivalent to invoking loadClass(name, false).

Parameters:

name - The binary name of the class

Returns:

The resulting Class object

Throws:

ClassNotFoundException - If the class was not found

loadClass

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

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

1. Invoke #findLoadedClass(String) to check if the class has already been loaded.

2. Invoke the loadClass method on the parent class loader. If the parent is null the class loader built-in to the virtual machine is used, instead.

3. Invoke the findClass(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(Class) method on the resulting Class object.

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

Parameters:

name - The binary name of the class

resolve - If true then resolve the class

Returns:

The resulting Class object

Throws:

ClassNotFoundException - If the class could not be found

findClass

protected Class<?> findClass(String name)
                      throws ClassNotFoundException

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. The default implementation throws a ClassNotFoundException.

Parameters:

name - The binary name of the class

Returns:

The resulting Class object

Throws:

ClassNotFoundException - If the class could not be found

Since:

1.2

findSystemClass

protected final Class<?> findSystemClass(String name)
                                  throws ClassNotFoundException

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

This method loads the class through the system class loader (see getSystemClassLoader()). The Class object returned might have more than one ClassLoader associated with it. Subclasses of ClassLoader need not usually invoke this method, because most class loaders need to override just findClass(String).

Parameters:

name - The binary name of the class

Returns:

The Class object for the specified name

Throws:

ClassNotFoundException - If the class could not be found

See Also:

ClassLoader(ClassLoader), getParent()

setSigners

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

No-op for compatibility.

getResource

public URL getResource(String name)

getResourceAsStream

public InputStream getResourceAsStream(String name)

Unsupported.

getSystemResourceAsStream

public static InputStream getSystemResourceAsStream(String name)

Unsupported.

getParent

public final ClassLoader getParent()

Returns the parent class loader for delegation. Some implementations may use null to represent the bootstrap class loader. This method will return null in such implementations if this class loader's parent is the bootstrap class loader.

getSystemClassLoader

public static ClassLoader getSystemClassLoader()

get system class loader.

Returns:

ClassLoader