org.jini.rio.boot
Class CommonClassLoader

java.lang.Object
  java.lang.ClassLoader
      java.security.SecureClassLoader
          java.net.URLClassLoader
              org.jini.rio.boot.CommonClassLoader

All Implemented Interfaces:

ComponentLoader

public class CommonClassLoader
extends URLClassLoader
implements ComponentLoader

The CommonClassLoader implements ComponentLoader interface and is created by the RioServiceDescriptor or RioActivatableServiceDescriptor when starting a Rio service and contains common declared platform JARs to be made available to its children.

The CommonClassLoader enables a platform oriented framework conducive towards creating a layered product. The resulting capabilities allow the declaration of JARs that are added to the CommonClassLoader, making the classes accessible by all ClassLoader instances which delegate to the CommonClassLoader. In this fashion a platform can be declared, initialized and made available.

The ClassLoader hierarchy when starting a Rio service is as follows :

AppCL
|
CommonClassLoader
+
|
+-------+-------+----...---+
| | |
Service-1CL Service-2CL Service-nCL

Method Summary

void	addCommonJARs(URL[] jars) Add common JARs
void	addComponent(String name, URL[] urls) Registers a class name, and the code source which is used as the search path to load the class.
static CommonClassLoader	getInstance() Get an instance of the CommonCLassLoader
URL[]	getURLs() Override getURLs to ensure when an Object is marshalled its annotation is correct
Object	load(String name) Creates an Object which has been added to the ComponentLoader using the addSystemComponent method, or is in the classpath of the ComponentLoader.
boolean	testComponentExistence(String name) Test whether a named component (Class) exists.
boolean	testResourceExistence(String name) Test whether a named resource exists.
String	toString() Returns a string representation of this class loader.

Methods inherited from class java.net.URLClassLoader

addURL, definePackage, findClass, findResource, findResources, getPermissions, newInstance, newInstance

Methods inherited from class java.security.SecureClassLoader

defineClass, defineClass

Methods inherited from class java.lang.ClassLoader

clearAssertionStatus, defineClass, defineClass, defineClass, defineClass, definePackage, findLibrary, findLoadedClass, findSystemClass, getPackage, getPackages, getParent, getResource, getResourceAsStream, getResources, getSystemClassLoader, getSystemResource, getSystemResourceAsStream, getSystemResources, loadClass, loadClass, resolveClass, setClassAssertionStatus, setDefaultAssertionStatus, setPackageAssertionStatus, setSigners

Methods inherited from class java.lang.Object

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

Method Detail

getInstance

public static CommonClassLoader getInstance()

Get an instance of the CommonCLassLoader

Returns:

The CommonClassLoader

getURLs

public URL[] getURLs()

Override getURLs to ensure when an Object is marshalled its annotation is correct

Overrides:

getURLs in class URLClassLoader

Returns:

Array of URLs

testComponentExistence

public boolean testComponentExistence(String name)

Description copied from interface: ComponentLoader

Test whether a named component (Class) exists.

Specified by:

testComponentExistence in interface ComponentLoader

Parameters:

name - The component name

Returns:

true If the requested component can be located, false otherwise.

See Also:

ComponentLoader.testComponentExistence(java.lang.String)

addCommonJARs

public void addCommonJARs(URL[] jars)

Add common JARs

Parameters:

jars - Array of URLs

testResourceExistence

public boolean testResourceExistence(String name)

Description copied from interface: ComponentLoader

Test whether a named resource exists. 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.

Specified by:

testResourceExistence in interface ComponentLoader

Parameters:

name - The resource name

Returns:

true If the requested resource can be located, false otherwise.

See Also:

ComponentLoader.testResourceExistence(java.lang.String)

addComponent

public void addComponent(String name,
                         URL[] urls)

Description copied from interface: ComponentLoader

Registers a class name, and the code source which is used as the search path to load the class.

Specified by:

addComponent in interface ComponentLoader

Parameters:

name - The name of the class

urls - Codebase for the class identified by the name parameter

See Also:

ComponentLoader.addComponent(java.lang.String, java.net.URL[])

load

public Object load(String name)
            throws ClassNotFoundException,
                   IllegalAccessException,
                   InstantiationException

Description copied from interface: ComponentLoader

Creates an Object which has been added to the ComponentLoader using the addSystemComponent method, or is in the classpath of the ComponentLoader. The Object is loaded from the registered code source.

Specified by:

load in interface ComponentLoader

Parameters:

name - The name of the class. The resulting class will be loaded and a new instance of the class created using a zero-arg contructor.

Throws:

ClassNotFoundException - - If the class cannot be located by the class loader or it has not been registered

IllegalAccessException - - If the Class or its nullary constructor is not accessible.

InstantiationException - - If this Class represents an abstract class, an interface, an array class, a primitive type, or void; or if the class has no nullary constructor; or if the instantiation fails for some other reason.

See Also:

ComponentLoader.load(java.lang.String)

toString

public String toString()

Returns a string representation of this class loader.

Overrides:

toString in class Object