org.apache.river.api.net

Class RFC3986URLClassLoader

java.lang.Object

java.lang.ClassLoader

java.security.SecureClassLoader

java.net.URLClassLoader

org.apache.river.api.net.RFC3986URLClassLoader

All Implemented Interfaces:

Closeable, AutoCloseable

Direct Known Subclasses:

PreferredClassLoader, RFC3986URLClassLoader.SubURLClassLoader

public class RFC3986URLClassLoader
extends URLClassLoader

This class loader is responsible for loading classes and resources from a list of URLs which can refer to either directories or JAR files. Classes loaded by this URLClassLoader are granted permission to access the URLs contained in the URL search list.

Unlike java.net.URLClassLoader, CodeSource.equals(java.lang.Object) and CodeSource.hashCode() is based on Certificate and RFC3986 Uri.equals(java.lang.Object) and Uri.hashCode(), not URL.equals(java.lang.Object). SecureClassLoader uses the overridden CodeSource equality as a key to cache ProtectionDomain's.

The following property -Dnet.jini.loader.codebaseAnnotation=URL may be set from the command line to revert to URL.equals(java.lang.Object) and URL.hashCode().

This allows implementors of Remote to do two things:

1. Utilise replication of codebase servers or mirrors.
2. Use different domain names to ensure separation of proxy classes that otherwise utilise identical jar files

The locking strategy of this ClassLoader is by default, the standard ClassLoader strategy. This ClassLoader is also thread safe, so can use a Parallel loading / synchronization strategy if the platform supports it.

Since:

3.0.0

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static class	RFC3986URLClassLoader.IndexFile
private static class	RFC3986URLClassLoader.SubURLClassLoader
private static class	RFC3986URLClassLoader.UriCodeSource To avoid CodeSource equals and hashCode methods in SecureClassLoader keys.
private static class	RFC3986URLClassLoader.URLFileHandler
private static class	RFC3986URLClassLoader.URLHandler
private static class	RFC3986URLClassLoader.URLJarHandler

Field Summary

Fields

Modifier and Type	Field and Description
private AccessControlContext	creationContext
private URLStreamHandlerFactory	factory
private List<RFC3986URLClassLoader.URLHandler>	handlerList
private Map<Uri,RFC3986URLClassLoader.URLHandler>	handlerMap
private static Logger	logger
private List<URL>	originalUrls
private List<URL>	searchList
private static boolean	uri value of "net.jini.loader.codebaseAnnotation" property, as cached at class initialization time.

Constructor Summary

Constructors

Constructor and Description
RFC3986URLClassLoader(URL[] urls) Constructs a new URLClassLoader instance.
RFC3986URLClassLoader(URL[] urls, ClassLoader parent) Constructs a new URLClassLoader instance.
RFC3986URLClassLoader(URL[] searchUrls, ClassLoader parent, URLStreamHandlerFactory factory) Constructs a new URLClassLoader instance.
RFC3986URLClassLoader(URL[] searchUrls, ClassLoader parent, URLStreamHandlerFactory factory, AccessControlContext context)

Method Summary

Modifier and Type	Method and Description
protected void	addURL(URL url) Adds the specified URL to the search list.
void	close() Java 6 compatible implementation that overrides Java 7 URLClassLoader.close() URLClassLoader implements Closeable in Java 7 to allow resources such as open jar files to be released.
private URL	createSearchURL(URL url) Returns an URL that will be checked if it contains the class or resource.
private RFC3986URLClassLoader.URLHandler	createURLFileHandler(URL url)
private RFC3986URLClassLoader.URLHandler	createURLHandler(URL url)
private RFC3986URLClassLoader.URLHandler	createURLJarHandler(URL url)
protected Package	definePackage(String packageName, Manifest manifest, URL url) Defines a new package using the information extracted from the specified manifest.
protected Class<?>	findClass(String clsName) Tries to locate and load the specified class using the known URLs.
(package private) Class<?>	findClassImpl(String className)
URL	findResource(String name) Returns an URL referencing the specified resource or null if the resource could not be found.
(package private) URL	findResourceImpl(String resName) Returns a URL among the given ones referencing the specified resource or null if no resource could be found.
Enumeration<URL>	findResources(String name) Returns all known URLs which point to the specified resource.
(package private) void	findResourcesImpl(String name, List<URL> result)
private static byte[]	getBytes(InputStream is) Converts an input stream into a byte array.
(package private) RFC3986URLClassLoader.URLHandler	getHandler(int num)
private ArrayList<URL>	getInternalURLs(URL root, String classpath) returns URLs referenced in the string classpath.
URL[]	getURLs() Returns the search list of this URLClassLoader.
private static boolean	isDirectory(URL url) Determines if the URL is pointing to a directory.
private boolean	isSealed(Manifest manifest, String dirName)
private void	makeNewHandler()
static URLClassLoader	newInstance(URL[] urls) Returns a new URLClassLoader instance for the given URLs and the system ClassLoader as its parent.
static URLClassLoader	newInstance(URL[] urls, ClassLoader parentCl) Returns a new URLClassLoader instance for the given URLs and the specified ClassLoader as its parent.

Methods inherited from class java.net.URLClassLoader

getPermissions, getResourceAsStream

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, getResource, getResources, 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

Field Detail

uri

private static final boolean uri

value of "net.jini.loader.codebaseAnnotation" property, as cached at class initialization time. It may contain malformed URLs.

logger

private static final Logger logger

originalUrls

private final List<URL> originalUrls

searchList

private final List<URL> searchList

handlerList

private final List<RFC3986URLClassLoader.URLHandler> handlerList

handlerMap

private final Map<Uri,RFC3986URLClassLoader.URLHandler> handlerMap

factory

private final URLStreamHandlerFactory factory

creationContext

private final AccessControlContext creationContext

Constructor Detail

RFC3986URLClassLoader

public RFC3986URLClassLoader(URL[] urls)

Constructs a new URLClassLoader instance. The newly created instance will have the system ClassLoader as its parent. URLs that end with "/" are assumed to be directories, otherwise they are assumed to be JAR files.

Parameters:

urls - the list of URLs where a specific class or file could be found.

Throws:

SecurityException - if a security manager exists and its checkCreateClassLoader() method doesn't allow creation of new ClassLoaders.

RFC3986URLClassLoader

public RFC3986URLClassLoader(URL[] urls,
                             ClassLoader parent)

Constructs a new URLClassLoader instance. The newly created instance will have the system ClassLoader as its parent. URLs that end with "/" are assumed to be directories, otherwise they are assumed to be JAR files.

Parameters:

urls - the list of URLs where a specific class or file could be found.

parent - the class loader to assign as this loader's parent.

Throws:

SecurityException - if a security manager exists and its checkCreateClassLoader() method doesn't allow creation of new class loaders.

RFC3986URLClassLoader

public RFC3986URLClassLoader(URL[] searchUrls,
                             ClassLoader parent,
                             URLStreamHandlerFactory factory)

Constructs a new URLClassLoader instance. The newly created instance will have the specified ClassLoader as its parent and use the specified factory to create stream handlers. URLs that end with "/" are assumed to be directories, otherwise they are assumed to be JAR files.

Parameters:

searchUrls - the list of URLs where a specific class or file could be found.

parent - the ClassLoader to assign as this loader's parent.

factory - the factory that will be used to create protocol-specific stream handlers.

Throws:

SecurityException - if a security manager exists and its checkCreateClassLoader() method doesn't allow creation of new ClassLoaders.

RFC3986URLClassLoader

RFC3986URLClassLoader(URL[] searchUrls,
                      ClassLoader parent,
                      URLStreamHandlerFactory factory,
                      AccessControlContext context)

Method Detail

addURL

protected void addURL(URL url)

Adds the specified URL to the search list.

Overrides:

addURL in class URLClassLoader

Parameters:

url - the URL which is to add.

findResources

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

Returns all known URLs which point to the specified resource.

Overrides:

findResources in class URLClassLoader

Parameters:

name - the name of the requested resource.

Returns:

the enumeration of URLs which point to the specified resource.

Throws:

IOException - if an I/O error occurs while attempting to connect.

findResourcesImpl

void findResourcesImpl(String name,
                       List<URL> result)

getBytes

private static byte[] getBytes(InputStream is)
                        throws IOException

Converts an input stream into a byte array.

Parameters:

is - the input stream

Returns:

byte[] the byte array

Throws:

IOException

getURLs

public URL[] getURLs()

Returns the search list of this URLClassLoader.

Overrides:

getURLs in class URLClassLoader

Returns:

the list of all known URLs of this instance.

isDirectory

private static boolean isDirectory(URL url)

Determines if the URL is pointing to a directory.

newInstance

public static URLClassLoader newInstance(URL[] urls)

Returns a new URLClassLoader instance for the given URLs and the system ClassLoader as its parent. The method loadClass() of the new instance will call SecurityManager.checkPackageAccess() before loading a class.

Parameters:

urls - the list of URLs that is passed to the new URLClassloader.

Returns:

the created URLClassLoader instance.

newInstance

public static URLClassLoader newInstance(URL[] urls,
                                         ClassLoader parentCl)

Returns a new URLClassLoader instance for the given URLs and the specified ClassLoader as its parent. The method loadClass() of the new instance will call the SecurityManager's checkPackageAccess() before loading a class.

Parameters:

urls - the list of URLs that is passed to the new URLClassloader.

parentCl - the parent class loader that is passed to the new URLClassloader.

Returns:

the created URLClassLoader instance.

findClass

protected Class<?> findClass(String clsName)
                      throws ClassNotFoundException

Tries to locate and load the specified class using the known URLs. If the class could be found, a class object representing the loaded class will be returned. The locking and synchronization strategy of this method is the responsibility of the caller.

Overrides:

findClass in class URLClassLoader

Parameters:

clsName - the name of the class which has to be found.

Returns:

the class that has been loaded.

Throws:

ClassNotFoundException - if the specified class cannot be loaded.

createSearchURL

private URL createSearchURL(URL url)
                     throws MalformedURLException

Returns an URL that will be checked if it contains the class or resource. If the file component of the URL is not a directory, a Jar URL will be created. We need to modify this implementation to allow URLStreamHandlerFactory's to use custom caching, such as the per ClassLoader caching used by Apache Geronimo. This would be very useful as it allows services to upgrade themselves by reloading and replacing their proxy's.

Returns:

java.net.URL a test URL

Throws:

MalformedURLException

findResource

public URL findResource(String name)

Returns an URL referencing the specified resource or null if the resource could not be found.

Overrides:

findResource in class URLClassLoader

Parameters:

name - the name of the requested resource.

Returns:

the URL which points to the given resource.

findResourceImpl

URL findResourceImpl(String resName)

Returns a URL among the given ones referencing the specified resource or null if no resource could be found.

Parameters:

resName - java.lang.String the name of the requested resource

Returns:

URL URL for the resource.

getHandler

RFC3986URLClassLoader.URLHandler getHandler(int num)

makeNewHandler

private void makeNewHandler()

createURLHandler

private RFC3986URLClassLoader.URLHandler createURLHandler(URL url)

createURLFileHandler

private RFC3986URLClassLoader.URLHandler createURLFileHandler(URL url)

createURLJarHandler

private RFC3986URLClassLoader.URLHandler createURLJarHandler(URL url)

definePackage

protected Package definePackage(String packageName,
                                Manifest manifest,
                                URL url)
                         throws IllegalArgumentException

Defines a new package using the information extracted from the specified manifest.

Overrides:

definePackage in class URLClassLoader

Parameters:

packageName - the name of the new package.

manifest - the manifest containing additional information for the new package.

url - the URL to the code source for the new package.

Returns:

the created package.

Throws:

IllegalArgumentException - if a package with the given name already exists.

isSealed

private boolean isSealed(Manifest manifest,
                         String dirName)

getInternalURLs

private ArrayList<URL> getInternalURLs(URL root,
                                       String classpath)

returns URLs referenced in the string classpath.

Parameters:

root - the jar URL that classpath is related to

classpath - the relative URLs separated by spaces

Returns:

URL[] the URLs contained in the string classpath.

findClassImpl

Class<?> findClassImpl(String className)

close

public void close()
           throws IOException

Java 6 compatible implementation that overrides Java 7 URLClassLoader.close() URLClassLoader implements Closeable in Java 7 to allow resources such as open jar files to be released. Closes any open resources and prevents this ClassLoader loading any additional classes or resources. TODO: Add support for nested Exceptions when support for Java 6 is dropped.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Overrides:

close in class URLClassLoader

Throws:

IOException