org.vrspace.server
Class VRSpaceLoader

java.lang.Object
  java.lang.ClassLoader
      java.security.SecureClassLoader
          java.net.URLClassLoader
              org.vrspace.server.VRSpaceLoader

All Implemented Interfaces:

java.lang.Runnable

public class VRSpaceLoader

extends java.net.URLClassLoader

implements java.lang.Runnable

Big bad class loader. It delegates all calls for all classes specified along with package name to parent classloader, this usually means system class loader. If this loader fails, looks for class in URLs specified by vrspace.loader.classpath property or by addURL/addDir calls. Behaviour changes when a class is specified without package name. Such classes are searched by package path. This allows us to change any class with another class without need to recompile. Still we need to respect polymorhpism etc. To use this feature, you'll have to 1) create new VRSpaceLoader explicitly or 2) use Thread.getContextClassLoader().loadClass() instead of Class.forName() To specify package search path, use vrspace.loader.packages property or call addPackage/removePackage. In properties, delimit urls/packages with ;

Nested Class Summary

class

VRSpaceLoader.ClassReference Work in progress

Constructor Summary

VRSpaceLoader()

VRSpaceLoader(java.net.URL[] urls)

VRSpaceLoader(java.net.URL[] urls, java.lang.ClassLoader parent)

VRSpaceLoader(java.net.URL[] urls, java.lang.ClassLoader parent, java.net.URLStreamHandlerFactory factory)

Method Summary

void	addDir(java.lang.String dir) Adds all files in a local directory to classpath
void	addDirs(java.lang.String[] dirs) Adds all files in specified directories to classpath
void	addPackage(java.lang.String name) Add a package to package search path.
protected void	addURL(java.net.URL url)
protected static void	checkURL(java.net.URL url)
protected java.lang.Class	findClass(java.lang.String name) Tries to guess package name of the specified class
java.net.URL	findResource(java.lang.String name) Debug only; this sometimes fails in conjunction with other classloaders.
java.lang.String	getPath() This returns full class search path in a string, delimited by File.pathSeparator
java.lang.Class	loadClass(java.lang.String name, boolean resolve) This actually loads a class.
static void	main(java.lang.String[] args)
void	removePackage(java.lang.String name) Remove a package from package search path.
void	run()
void	startServer(java.lang.String[] args) Starts vrspace server with specified arguments

Methods inherited from class java.net.URLClassLoader

definePackage, 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

Constructor Detail

VRSpaceLoader

public VRSpaceLoader()

VRSpaceLoader

public VRSpaceLoader(java.net.URL[] urls)

VRSpaceLoader

public VRSpaceLoader(java.net.URL[] urls,
                     java.lang.ClassLoader parent)

VRSpaceLoader

public VRSpaceLoader(java.net.URL[] urls,
                     java.lang.ClassLoader parent,
                     java.net.URLStreamHandlerFactory factory)

Method Detail

addPackage

public void addPackage(java.lang.String name)

Add a package to package search path.

removePackage

public void removePackage(java.lang.String name)

Remove a package from package search path.

addURL

protected void addURL(java.net.URL url)

checkURL

protected static void checkURL(java.net.URL url)
                        throws java.io.IOException

Throws:

java.io.IOException

addDir

public void addDir(java.lang.String dir)
            throws java.io.IOException,
                   java.net.MalformedURLException

Adds all files in a local directory to classpath

Throws:

java.io.IOException

java.net.MalformedURLException

getPath

public java.lang.String getPath()

This returns full class search path in a string, delimited by File.pathSeparator

addDirs

public void addDirs(java.lang.String[] dirs)
             throws java.io.IOException,
                    java.net.MalformedURLException

Adds all files in specified directories to classpath

Throws:

java.io.IOException

java.net.MalformedURLException

findClass

protected java.lang.Class findClass(java.lang.String name)
                             throws java.lang.ClassNotFoundException

Tries to guess package name of the specified class

Throws:

java.lang.ClassNotFoundException

loadClass

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

This actually loads a class. If parent fails, searches for class definition all jars/dirs/urls specified in the classpath.

Throws:

java.lang.ClassNotFoundException

findResource

public java.net.URL findResource(java.lang.String name)

Debug only; this sometimes fails in conjunction with other classloaders.

run

public void run()

Specified by:

run in interface java.lang.Runnable

main

public static void main(java.lang.String[] args)

startServer

public void startServer(java.lang.String[] args)
                 throws java.lang.Exception

Starts vrspace server with specified arguments

Throws:

java.lang.Exception

See Also:

Server