org.smartfrog.sfcore.common
Class BaseClassLoader

java.lang.Object
  java.lang.ClassLoader
      org.smartfrog.sfcore.common.BaseClassLoader

Direct Known Subclasses:

URLClassLoader

public class BaseClassLoader
extends java.lang.ClassLoader

Basic class loader functionality. Provides system class lookups only. Hook methods are provided for subclasses to provide different mechanisms to locate a Class or its defining bytes.

Constructor Summary

BaseClassLoader()
Constructor.

Method Summary

protected java.lang.Class	findClass(java.lang.String className) Hook method to locate a given class.
protected byte[]	findClassBytes(java.lang.String className) This classloaded expects to find everything using the primordial classloader, so this always throws an IOException.
java.lang.Class	loadClass(java.lang.String className) Overriden to forward to the expanded method with resolve set to true, since clients will generally want to resolve all their classes before returning.
java.lang.Class	loadClass(java.lang.String className, boolean resolveIt) Main method to locate or load a given class.

Methods inherited from class java.lang.ClassLoader

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

Methods inherited from class java.lang.Object

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

Constructor Detail

BaseClassLoader

public BaseClassLoader()

Constructor.

Method Detail

loadClass

public java.lang.Class loadClass(java.lang.String className)
                          throws java.lang.ClassNotFoundException

Overriden to forward to the expanded method with resolve set to true, since clients will generally want to resolve all their classes before returning.

Overrides:

loadClass in class java.lang.ClassLoader

Parameters:

className - class to load

Returns:

requested class

Throws:

java.lang.ClassNotFoundException - class not found

loadClass

public java.lang.Class loadClass(java.lang.String className,
                                 boolean resolveIt)
                          throws java.lang.ClassNotFoundException

Main method to locate or load a given class. Calls findClass to locate a Class first, it not found calls findClassBytes to see it defining bytes can be downloaded from somewhere. If defined from bytes the class is maintained in an internal table.

Overrides:

loadClass in class java.lang.ClassLoader

Parameters:

className - class to locate or load

resolveIt - whether to resolve referred classes

Returns:

Class object

Throws:

java.lang.ClassNotFoundException - class not found

findClass

protected java.lang.Class findClass(java.lang.String className)
                             throws java.lang.ClassNotFoundException

Hook method to locate a given class. Looks in the maintained classes table to locate a previously loaded class. Then asks primordial classloader to load class.

Overrides:

findClass in class java.lang.ClassLoader

Parameters:

className - class to locate

Returns:

requested class; from table or system

Throws:

java.lang.ClassNotFoundException - class not found

findClassBytes

protected byte[] findClassBytes(java.lang.String className)
                         throws java.io.IOException

This classloaded expects to find everything using the primordial classloader, so this always throws an IOException. Subclasses can implement this method to locate defining bytes elsewhere (eg. at a URL)

Parameters:

className - class to find bytes for

Returns:

bytes defining class

Throws:

java.io.IOException - error while trying to locate or load bytes