org.apache.wicket.application

Class ReloadingClassLoader

java.lang.Object

java.lang.ClassLoader

java.security.SecureClassLoader

java.net.URLClassLoader

org.apache.wicket.application.ReloadingClassLoader

All Implemented Interfaces:

Closeable, AutoCloseable

public class ReloadingClassLoader
extends URLClassLoader

Custom ClassLoader that reverses the classloader lookups, and that is able to notify a listener when a class file is changed.

Author:

Jean-Baptiste Quenot

Constructor Summary

Constructors

Constructor and Description
ReloadingClassLoader(ClassLoader parent) Create a new reloading ClassLoader from a list of URLs, and initialize the ModificationWatcher to detect class file modifications

Method Summary

Modifier and Type	Method and Description
static void	addLocation(URL url) Add the location of a directory containing class files
void	destroy() Remove the ModificationWatcher from the current reloading class loader
static void	excludePattern(String pattern) Exclude a pattern
static Set<URL>	getLocations() Returns the list of all configured locations of directories containing class files
static List<String>	getPatterns() Returns the list of all configured inclusion or exclusion patterns
URL	getResource(String name) Gets a resource from this ClassLoader.
static void	includePattern(String pattern) Include a pattern
Class<?>	loadClass(String name, boolean resolve) Loads the class from this ClassLoader.
void	setListener(IChangeListener<Class<?>> listener) Sets the listener that will be notified when a class changes
protected boolean	tryClassHere(String name)

Methods inherited from class java.net.URLClassLoader

addURL, close, definePackage, findClass, findResource, findResources, getPermissions, getResourceAsStream, getURLs, 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, getClassLoadingLock, getPackage, getPackages, getParent, getResources, getSystemClassLoader, getSystemResource, getSystemResourceAsStream, getSystemResources, loadClass, registerAsParallelCapable, 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

ReloadingClassLoader

public ReloadingClassLoader(ClassLoader parent)

Create a new reloading ClassLoader from a list of URLs, and initialize the ModificationWatcher to detect class file modifications

Parameters:

parent - the parent classloader in case the class file cannot be loaded from the above locations

Method Detail

tryClassHere

protected boolean tryClassHere(String name)

Parameters:

name -

Returns:

true if class if found, false otherwise

includePattern

public static void includePattern(String pattern)

Include a pattern

Parameters:

pattern - the pattern to include

excludePattern

public static void excludePattern(String pattern)

Exclude a pattern

Parameters:

pattern - the pattern to exclude

getPatterns

public static List<String> getPatterns()

Returns the list of all configured inclusion or exclusion patterns

Returns:

list of patterns as String

addLocation

public static void addLocation(URL url)

Add the location of a directory containing class files

Parameters:

url - the URL for the directory

getLocations

public static Set<URL> getLocations()

Returns the list of all configured locations of directories containing class files

Returns:

list of locations as URL

getResource

public final URL getResource(String name)

Gets a resource from this ClassLoader. If the resource does not exist in this one, we check the parent. Please note that this is the exact opposite of the ClassLoader spec. We use it to work around inconsistent class loaders from third party vendors.

Overrides:

getResource in class ClassLoader

Parameters:

name - of resource

loadClass

public final Class<?> loadClass(String name,
                                boolean resolve)
                         throws ClassNotFoundException

Loads the class from this ClassLoader. If the class does not exist in this one, we check the parent. Please note that this is the exact opposite of the ClassLoader spec. We use it to load the class from the same classloader as WicketFilter or WicketServlet. When found, the class file is watched for modifications.

Overrides:

loadClass in class ClassLoader

Parameters:

name - the name of the class

resolve - if true then resolve the class

Returns:

the resulting Class object

Throws:

ClassNotFoundException - if the class could not be found

setListener

public void setListener(IChangeListener<Class<?>> listener)

Sets the listener that will be notified when a class changes

Parameters:

listener - the listener to notify upon class change

destroy

public void destroy()

Remove the ModificationWatcher from the current reloading class loader