org.apache.jdo.impl.enhancer
Class EnhancerClassLoader

java.lang.Object
  java.lang.ClassLoader
      java.security.SecureClassLoader
          java.net.URLClassLoader
              org.apache.jdo.impl.enhancer.EnhancerClassLoader

public class EnhancerClassLoader

extends java.net.URLClassLoader

Implements a ClassLoader which automatically enchances the .class files according to the EnhancerMetaData information in the jar archive.

Author:

Yury Kamen, Martin Zaun

Nested Class Summary

Nested classes inherited from class java.lang.ClassLoader

Field Summary

private java.security.AccessControlContext	acc
private boolean	debug
static java.lang.String	DO_TIMING_STATISTICS
private boolean	doTiming
private ClassFileEnhancer	enhancer
private EnhancerMetaData	metaData
private java.io.PrintWriter	out
private java.lang.ref.WeakReference	outByteCodeRef
private java.util.Properties	settings
private sun.misc.URLClassPath	ucp
static java.lang.String	VERBOSE_LEVEL
static java.lang.String	VERBOSE_LEVEL_DEBUG
static java.lang.String	VERBOSE_LEVEL_QUIET
static java.lang.String	VERBOSE_LEVEL_VERBOSE
static java.lang.String	VERBOSE_LEVEL_WARN

Fields inherited from class java.security.SecureClassLoader

Fields inherited from class java.lang.ClassLoader

Constructor Summary

	EnhancerClassLoader(java.lang.String classpath, EnhancerMetaData metaData, java.util.Properties settings, java.io.PrintWriter out) Creates a new EnhancerClassLoader for the specified url.
	EnhancerClassLoader(java.lang.String classpath, java.util.Properties settings, java.io.PrintWriter out) Creates a new EnhancerClassLoader for the specified url.
protected	EnhancerClassLoader(java.net.URL[] urls) Creates a new EnhancerClassLoader for the specified url.
protected	EnhancerClassLoader(java.net.URL[] urls, java.lang.ClassLoader loader) Creates a new EnhancerClassLoader for the specified url.
	EnhancerClassLoader(java.net.URL[] urls, EnhancerMetaData metaData, java.util.Properties settings, java.io.PrintWriter out) Creates a new EnhancerClassLoader for the specified url.
	EnhancerClassLoader(java.net.URL[] urls, java.util.Properties settings, java.io.PrintWriter out) Creates a new EnhancerClassLoader for the specified url.

Method Summary

protected void	addURL(java.net.URL url) Appends the specified URL to the list of URLs to search for classes and resources.
(package private) static void	affirm(boolean cond)
private void	checkUCP(java.net.URL[] urls)
private java.lang.Class	defineClass(java.lang.String name, sun.misc.Resource res) Defines a Class using the class bytes obtained from the specified Resource.
private byte[]	enhance(java.lang.String name, byte[] data, int off, int len)
private java.lang.Class	findAndEnhanceClass(java.lang.String name) Finds and loads the class with the specified name from the URL search path.
private void	init(EnhancerMetaData metaData, java.util.Properties settings, java.io.PrintWriter out) Initialize the EnhancingClassLoader
private boolean	isSealed(java.lang.String name, java.util.jar.Manifest man) Returns true if the specified package name is sealed according to the given manifest.
java.lang.Class	loadClass(java.lang.String name, boolean resolve)
private void	message()
private void	message(java.lang.Exception e)
private void	message(java.lang.String s)
static java.net.URL[]	pathToURLs(java.lang.String classpath)

Methods inherited from class java.net.URLClassLoader

definePackage, findClass, findResource, findResources, getPermissions, getURLs, newInstance, newInstance

Methods inherited from class java.security.SecureClassLoader

defineClass

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, resolveClass, setClassAssertionStatus, setDefaultAssertionStatus, setPackageAssertionStatus, setSigners

Methods inherited from class java.lang.Object

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

Field Detail

DO_TIMING_STATISTICS

public static final java.lang.String DO_TIMING_STATISTICS

See Also:

Constant Field Values

VERBOSE_LEVEL

public static final java.lang.String VERBOSE_LEVEL

See Also:

Constant Field Values

VERBOSE_LEVEL_QUIET

public static final java.lang.String VERBOSE_LEVEL_QUIET

See Also:

Constant Field Values

VERBOSE_LEVEL_WARN

public static final java.lang.String VERBOSE_LEVEL_WARN

See Also:

Constant Field Values

VERBOSE_LEVEL_VERBOSE

public static final java.lang.String VERBOSE_LEVEL_VERBOSE

See Also:

Constant Field Values

VERBOSE_LEVEL_DEBUG

public static final java.lang.String VERBOSE_LEVEL_DEBUG

See Also:

Constant Field Values

debug

private boolean debug

doTiming

private boolean doTiming

out

private java.io.PrintWriter out

enhancer

private ClassFileEnhancer enhancer

metaData

private EnhancerMetaData metaData

settings

private java.util.Properties settings

outByteCodeRef

private java.lang.ref.WeakReference outByteCodeRef

ucp

private final sun.misc.URLClassPath ucp

acc

private final java.security.AccessControlContext acc

Constructor Detail

EnhancerClassLoader

protected EnhancerClassLoader(java.net.URL[] urls)

Creates a new EnhancerClassLoader for the specified url.

Parameters:

urls - the classpath to search

EnhancerClassLoader

protected EnhancerClassLoader(java.net.URL[] urls,
                              java.lang.ClassLoader loader)

Creates a new EnhancerClassLoader for the specified url.

Parameters:

urls - the classpath to search

EnhancerClassLoader

public EnhancerClassLoader(java.lang.String classpath,
                           java.util.Properties settings,
                           java.io.PrintWriter out)

Creates a new EnhancerClassLoader for the specified url.

Parameters:

classpath - the classpath to search

EnhancerClassLoader

public EnhancerClassLoader(java.net.URL[] urls,
                           java.util.Properties settings,
                           java.io.PrintWriter out)

Creates a new EnhancerClassLoader for the specified url.

Parameters:

urls - the classpath to search

EnhancerClassLoader

public EnhancerClassLoader(java.lang.String classpath,
                           EnhancerMetaData metaData,
                           java.util.Properties settings,
                           java.io.PrintWriter out)

Creates a new EnhancerClassLoader for the specified url.

Parameters:

classpath - the classpath to search

EnhancerClassLoader

public EnhancerClassLoader(java.net.URL[] urls,
                           EnhancerMetaData metaData,
                           java.util.Properties settings,
                           java.io.PrintWriter out)

Creates a new EnhancerClassLoader for the specified url.

Parameters:

urls - the classpath to search

Method Detail

pathToURLs

public static java.net.URL[] pathToURLs(java.lang.String classpath)

affirm

static final void affirm(boolean cond)

message

private final void message()

message

private final void message(java.lang.String s)

message

private final void message(java.lang.Exception e)

addURL

protected void addURL(java.net.URL url)

Appends the specified URL to the list of URLs to search for classes and resources.

Parameters:

url - the URL to be added to the search path of URLs

checkUCP

private void checkUCP(java.net.URL[] urls)

init

private void init(EnhancerMetaData metaData,
                  java.util.Properties settings,
                  java.io.PrintWriter out)

Initialize the EnhancingClassLoader

loadClass

public java.lang.Class loadClass(java.lang.String name,
                                 boolean resolve)
                          throws java.lang.ClassNotFoundException

Throws:

java.lang.ClassNotFoundException

findAndEnhanceClass

private java.lang.Class findAndEnhanceClass(java.lang.String name)
                                     throws java.lang.ClassNotFoundException

Finds and loads the class with the specified name from the URL search path. Any URLs referring to JAR files are loaded and opened as needed until the class is found.

Parameters:

name - the name of the class

Returns:

the resulting class

Throws:

java.lang.ClassNotFoundException - if the class could not be found

defineClass

private java.lang.Class defineClass(java.lang.String name,
                                    sun.misc.Resource res)
                             throws java.io.IOException,
                                    java.lang.ClassNotFoundException

Defines a Class using the class bytes obtained from the specified Resource. The resulting Class must be resolved before it can be used.

Throws:

java.io.IOException

java.lang.ClassNotFoundException

enhance

private byte[] enhance(java.lang.String name,
                       byte[] data,
                       int off,
                       int len)
                throws java.lang.ClassNotFoundException

Throws:

java.lang.ClassNotFoundException

isSealed

private boolean isSealed(java.lang.String name,
                         java.util.jar.Manifest man)

Returns true if the specified package name is sealed according to the given manifest.