org.hotswap.agent.util.classloader

Class WatchResourcesClassLoader

java.lang.Object

java.lang.ClassLoader

java.security.SecureClassLoader

java.net.URLClassLoader

org.hotswap.agent.util.classloader.WatchResourcesClassLoader

All Implemented Interfaces:

Closeable, AutoCloseable

public class WatchResourcesClassLoader
extends URLClassLoader

Special URL classloader to get only changed resources from URL. Use this classloader to support watchResources property. This classloader checks if the resource was modified after application startup and in that case delegates getResource()/getResources() to custom URL classloader. Otherwise returns null or resource from paren classloader (depending on searchParent property).

Author:

Jiri Bubnik

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	WatchResourcesClassLoader.UrlOnlyClassLoader Helper classloader to get resources from list of urls only.

Constructor Summary

Constructors

Constructor and Description
WatchResourcesClassLoader()
WatchResourcesClassLoader(boolean searchParent)
WatchResourcesClassLoader(ClassLoader classLoader)

Method Summary

Modifier and Type	Method and Description
String	getClasspath() Support for classpath builder on Tomcat.
URL	getResource(String name) Returns URL only if the resource is found in changedURL and was actually changed after instantiation of this classloader.
InputStream	getResourceAsStream(String name)
Enumeration<URL>	getResources(String name) Returns only a single instance of the changed resource.
void	initExtraPath(URL[] extraPath) Configure new instance with urls and watcher service.
void	initWatchResources(URL[] watchResources, Watcher watcher) Configure new instance with urls and watcher service.
boolean	isResourceChanged(URL url) Check if the resource was changed after this classloader instantiaton.
void	setSearchParent(boolean searchParent)

Methods inherited from class java.net.URLClassLoader

addURL, close, definePackage, findClass, findResource, findResources, getPermissions, 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, getSystemClassLoader, getSystemResource, getSystemResourceAsStream, getSystemResources, loadClass, 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

WatchResourcesClassLoader

public WatchResourcesClassLoader()

WatchResourcesClassLoader

public WatchResourcesClassLoader(boolean searchParent)

WatchResourcesClassLoader

public WatchResourcesClassLoader(ClassLoader classLoader)

Method Detail

setSearchParent

public void setSearchParent(boolean searchParent)

initExtraPath

public void initExtraPath(URL[] extraPath)

Configure new instance with urls and watcher service.

Parameters:

extraPath - the URLs from which to load resources

initWatchResources

public void initWatchResources(URL[] watchResources,
                               Watcher watcher)

Configure new instance with urls and watcher service.

Parameters:

watchResources - the URLs from which to load resources

watcher - watcher service to register watch events

isResourceChanged

public boolean isResourceChanged(URL url)

Check if the resource was changed after this classloader instantiaton.

Parameters:

url - full URL of the file

Returns:

true if was changed after instantiation

getResource

public URL getResource(String name)

Returns URL only if the resource is found in changedURL and was actually changed after instantiation of this classloader.

Overrides:

getResource in class ClassLoader

getResourceAsStream

public InputStream getResourceAsStream(String name)

Overrides:

getResourceAsStream in class URLClassLoader

getResources

public Enumeration<URL> getResources(String name)
                              throws IOException

Returns only a single instance of the changed resource. There are conflicting requirements for other resources inclusion. This class should "hide" the original resource, hence it should not be included in the resoult. On the other hand, there may be resource with the same name in other JAR which should be included and now is hidden (for example multiple persistence.xml). Maybe a new property to influence this behaviour?

Overrides:

getResources in class ClassLoader

Throws:

IOException

getClasspath

public String getClasspath()

Support for classpath builder on Tomcat.