org.objectweb.jac.core
Class JacLoader

java.lang.Object
  |
  +--java.lang.ClassLoader
        |
        +--org.objectweb.jac.core.JacLoader

public class JacLoader

extends ClassLoader

The JAC specific class loader for JAC objects.

This loader does the following things :

• load a set of Properties from all the found "jac.prop" files
• get from them the choosen wrappeeTranslator
• instanciate the choosen wrappeTranslator
• replace the system class loader.
• then for each loaded class it can delegates the translation of JAC objects to the choosen WrappeeTranslator.

See Also:

WrappeeTranslator

Constructor Summary

JacLoader(boolean write, boolean clean)
Create a JacLoader.

JacLoader(boolean write, boolean clean, ClassLoader otherClassLoader)
Create a JacLoader.

Method Summary

protected boolean	analyzeClass(String classname) Tells wether a defered class's bytecode should be analyzed
static boolean	classIsToBeAdapted(String name) Tell wether a class is to be adapted or not.
boolean	deferClass(String classname) Tells wether to defer loading of a class to the parent ClassLoader
static void	displayClassInfo(String name) display some information about a class Only use for debug purpose to verify that the class has been patched correctly.
URL	getResource(String name)
InputStream	getResourceAsStream(String name)
boolean	isLoaded(String classname) Returns true if the class is already loaded.
protected Class	loadClass(String class_name, boolean resolve)
static void	main(String[] args) Usage: java org.objectweb.jac.core.JacLoader [class]
void	readProperties(Properties props) Use JacPropLoader to read some JAC properties
void	run(String classname, String[] args) Loads a class and calls main() in that class.
void	setWrappeeTranslator(WrappeeTranslator wt)

Methods inherited from class java.lang.ClassLoader

clearAssertionStatus, defineClass, defineClass, defineClass, definePackage, findClass, findLibrary, findLoadedClass, findResource, findResources, findSystemClass, getPackage, getPackages, getParent, getResources, getSystemClassLoader, getSystemResource, getSystemResourceAsStream, getSystemResources, loadClass, 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

JacLoader

public JacLoader(boolean write,
                 boolean clean,
                 ClassLoader otherClassLoader)
          throws Exception

Create a JacLoader.

Parameters:

write - if true, caches the tranlated classes on disk

clean - if true, clears the disk cache

otherClassLoader - if not null, indicates another ClassLoader where to search for classes not in original ClassPath

JacLoader

public JacLoader(boolean write,
                 boolean clean)
          throws Exception

Create a JacLoader. Same as JacLoader(boolean,boolean,null).

Parameters:

write - if true, caches the tranlated classes on disk

clean - if true, clears the disk cache

Method Detail

setWrappeeTranslator

public void setWrappeeTranslator(WrappeeTranslator wt)

deferClass

public boolean deferClass(String classname)

Tells wether to defer loading of a class to the parent ClassLoader

Parameters:

classname - name of the class

Returns:

true if we should defer the loading of that class

analyzeClass

protected boolean analyzeClass(String classname)

Tells wether a defered class's bytecode should be analyzed

Parameters:

classname - the name of the class

loadClass

protected Class loadClass(String class_name,
                          boolean resolve)
                   throws ClassNotFoundException

Overrides:

loadClass in class ClassLoader

ClassNotFoundException

getResourceAsStream

public InputStream getResourceAsStream(String name)

Overrides:

getResourceAsStream in class ClassLoader

getResource

public URL getResource(String name)

Overrides:

getResource in class ClassLoader

classIsToBeAdapted

public static boolean classIsToBeAdapted(String name)

Tell wether a class is to be adapted or not. All data are extracted from the jac.prop files located a various place.

Parameters:

name - a String value

Returns:

a boolean value (true if to be adpated).

See Also:

JacPropLoader, JacPropTools

displayClassInfo

public static void displayClassInfo(String name)

display some information about a class
Only use for debug purpose to verify that the class has been patched correctly.

Parameters:

name - the class to display

See Also:

ClassLoader

isLoaded

public boolean isLoaded(String classname)

Returns true if the class is already loaded.

Parameters:

classname - the class name to test

Returns:

true if already loaded

run

public void run(String classname,
                String[] args)
         throws Throwable

Loads a class and calls main() in that class.

This method was extracted "as is" from javassist 1.0 from Shigeru Chiba.

Javassist Homepage

Parameters:

classname - the loaded class.

args - parameters passed to main().

Throwable

readProperties

public void readProperties(Properties props)

Use JacPropLoader to read some JAC properties

Parameters:

props - the properties to read

main

public static void main(String[] args)
                 throws Exception

Usage: java org.objectweb.jac.core.JacLoader [class]

Exception