org.jboss.net.protocol

Class URLStreamHandlerFactory

java.lang.Object

org.jboss.net.protocol.URLStreamHandlerFactory

All Implemented Interfaces:

java.net.URLStreamHandlerFactory

public class URLStreamHandlerFactory
extends java.lang.Object
implements java.net.URLStreamHandlerFactory

A factory for loading URL protocol handlers. This is based on Sun's URL mechanism, in that Handler classes will be searched for in the packages specified by the java.protocol.handler.pkgs property are searched for classes matching the protocol + ".Handler" classname. The default JBoss package "org.jboss.net.protocol" is searched even if not specified in the java.protocol.handler.pkgs property.

This factory is installed by the default server implementaion to ensure that protocol handlers not in the system classpath are located. The thread context class is used first followed by the Class.forName method.

Version:

$Revision$

Field Summary

Fields

Modifier and Type	Field and Description
private static java.lang.ThreadLocal	createURLStreamHandlerProtocol This thread local is used to prevent recursion in the createURLStreamHandler method.
private static java.util.Map	handlerMap A map of protocol names to handlers.
private java.lang.String[]	handlerPkgs The current packages prefixes determined from the java.protocol.handler.pkgs property + the org.jboss.net.protocol default package.
private java.lang.String	lastHandlerPkgs The last java.protocol.handler.pkgs value.
private static org.jboss.logging.Logger	log Class logger.
static java.lang.String	PACKAGE_PREFIX The package prefix where JBoss protocol handlers live.
static java.lang.String[]	PROTOCOLS A list of JBoss specific protocols for preloading.

Constructor Summary

Constructors

Constructor and Description
URLStreamHandlerFactory()

Method Summary

Modifier and Type	Method and Description
private void	checkHandlerPkgs() See if the java.protocol.handler.pkgs system property has changed and if it has, parse it to update the handlerPkgs array.
static void	clear() Clear the current protocol to handler map.
java.net.URLStreamHandler	createURLStreamHandler(java.lang.String protocol) Search the handlerPkgs for URLStreamHandler classes matching the pkg + protocol + ".Handler" naming convention.
static void	preload() Preload the JBoss specific protocol handlers, so that URL knows about them even if the handler factory is changed.

Methods inherited from class java.lang.Object

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

Field Detail

log

private static final org.jboss.logging.Logger log

Class logger.

PACKAGE_PREFIX

public static final java.lang.String PACKAGE_PREFIX

The package prefix where JBoss protocol handlers live.

See Also:

Constant Field Values

handlerMap

private static java.util.Map handlerMap

A map of protocol names to handlers. Since there can only be one URLStreamHandlerFactory installed, this is a static map that may be cleared.

createURLStreamHandlerProtocol

private static java.lang.ThreadLocal createURLStreamHandlerProtocol

This thread local is used to prevent recursion in the createURLStreamHandler method. Resolving the protocol handler class can end up creating a new URL which can loop back into this factory with a stack like:

      URLStreamHandlerFactory that use the TCL. See bug#669043
      createURLStreamHandler():146, URLStreamHandlerFactory.java
      getURLStreamHandler():1057, URL.java
      ():405, URL.java
      ():329, URL.java
      ():321, URL.java
      ():540, URLClassPath.java
      run():319, URLClassPath.java
      doPrivileged():-1, AccessController.java
      getLoader():308, URLClassPath.java
      getLoader():285, URLClassPath.java
      findResource():136, URLClassPath.java
      run():351, URLClassLoader.java
      doPrivileged():-1, AccessController.java
      findResource():348, URLClassLoader.java
      getResource():780, ClassLoader.java
      getResourceLocally():250, UnifiedClassLoader.java
      getResourceFromClassLoader():333, UnifiedLoaderRepository3.java
      getResource():243, UnifiedLoaderRepository3.java
      getResource():228, UnifiedClassLoader3.java
     

So we detect recursion based on the protocol value matches the current createURLStreamHandlerProtocol setting.

handlerPkgs

private java.lang.String[] handlerPkgs

The current packages prefixes determined from the java.protocol.handler.pkgs property + the org.jboss.net.protocol default package.

lastHandlerPkgs

private java.lang.String lastHandlerPkgs

The last java.protocol.handler.pkgs value. Used to determine if the java.protocol.handler.pkgs property has changed since handlerPkgs was last built.

PROTOCOLS

public static final java.lang.String[] PROTOCOLS

A list of JBoss specific protocols for preloading.

Constructor Detail

URLStreamHandlerFactory

public URLStreamHandlerFactory()

Method Detail

preload

public static void preload()

Preload the JBoss specific protocol handlers, so that URL knows about them even if the handler factory is changed.

clear

public static void clear()

Clear the current protocol to handler map. The map will be rebuilt as protocol handlers are requested.

createURLStreamHandler

public java.net.URLStreamHandler createURLStreamHandler(java.lang.String protocol)

Search the handlerPkgs for URLStreamHandler classes matching the pkg + protocol + ".Handler" naming convention.

Specified by:

createURLStreamHandler in interface java.net.URLStreamHandlerFactory

Parameters:

protocol - The protocol to create a stream handler for

Returns:

The protocol handler or null if not found

checkHandlerPkgs

private void checkHandlerPkgs()

See if the java.protocol.handler.pkgs system property has changed and if it has, parse it to update the handlerPkgs array.