com.sapportals.wcm.crt

Class CrtClassLoaderRegistry

java.lang.Object
  java.lang.ClassLoader
      com.sapportals.wcm.crt.CrtClassLoaderRegistry

public final class CrtClassLoaderRegistry

extends ClassLoader

Provides a registry for class loaders.

getClassLoader provides a class loader that aggregates all registered class loaders to find and load classes and resources.

Registered class loaders are chained creating one virtual class loader. From the perspective of the JDK, it's all one classloader. Internally, the class loader chain searches like a classpath.

The following code shows an example how to use this registry:

 
     // add your personal class loader (this should be done only once)
     CrtClassLoaderRegistry.addClassLoader( MyPrettyCoolClass.class.getClassLoader() );
     ...
     // load another class with this class loader
     MyOtherClass myOtherInstance = null;
     try {
       Class myOtherClass = CrtClassLoaderRegistry.forName( "com.company.prg.MyOtherClass" );
       myOtherInstance = (MyOtherClass)myOtherClass.newInstance();
     }
     catch( .... x ) {
       ....
     }
  
  
 

Copyright (c) SAP AG 2001-2002

Method Summary

static void	addClassLoader(ClassLoader newLoader) Register a class loader to the component runtime.
static void	addClassLoader(String id, ClassLoader newLoader) Register a class loader with an optional id to the component runtime.
static void	addClassLoader(String id, ClassLoader newLoader, Set hints) Register a class loader with an optional id to the component runtime.
static void	addClassLoaderRegistryListener(IClassLoaderRegistryListener l)
protected Class	findClass(String name)
protected URL	findResource(String name)
protected Enumeration	findResources(String name)
static Class	forName(String className) Returns the Class object associated with the class or interface with the given string name, using this registry.
static ClassLoader	getClassLoader() Returns the component runtime default class loader.
static void	removeClassLoaderRegistryListener(IClassLoaderRegistryListener l)

Methods inherited from class java.lang.ClassLoader

clearAssertionStatus, 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, toString, wait, wait, wait

Method Detail

findClass

protected Class findClass(String name)
                   throws ClassNotFoundException

Throws:

ClassNotFoundException

findResources

protected Enumeration findResources(String name)
                             throws IOException

Throws:

IOException

findResource

protected URL findResource(String name)

addClassLoader

public static void addClassLoader(ClassLoader newLoader)

Register a class loader to the component runtime.

Parameters:

newLoader - The new class loader instance to be added.

addClassLoader

public static void addClassLoader(String id,
                                  ClassLoader newLoader)

Register a class loader with an optional id to the component runtime. If a class loader with the same id was already registered, this method replaces the former loader with the newLoader .

If newLoader is null the class loader with id is removed.

If id is null the class loader is added anonymous and cannot be removed.

Parameters:

id - The optional id of this class loader

newLoader - The new class loader instance to be added.

addClassLoader

public static void addClassLoader(String id,
                                  ClassLoader newLoader,
                                  Set hints)

Register a class loader with an optional id to the component runtime. If a class loader with the same id was already registered, this method replaces the former loader with the newLoader .

This method is meant as a hook for improved class loading speed. Each class loader newLoader registered comes bundled with a set of Java package names that are in this loaders scope.

Parameters:

id - The id of this class loader (if no id is provided, an automatically generated one will be used)

newLoader - The new class loader instance to be added

hints - A set of package names in the loader's scope

getClassLoader

public static ClassLoader getClassLoader()

Returns the component runtime default class loader. This class loader uses all registered class loaders to find and load class files and resources.

Returns:

The chained class loader

forName

public static Class forName(String className)
                     throws ClassNotFoundException

Returns the Class object associated with the class or interface with the given string name, using this registry.

Parameters:

className -

Returns:

Class object

Throws:

ClassNotFoundException

addClassLoaderRegistryListener

public static void addClassLoaderRegistryListener(IClassLoaderRegistryListener l)

removeClassLoaderRegistryListener

public static void removeClassLoaderRegistryListener(IClassLoaderRegistryListener l)