org.rhq.enterprise.server.plugin.pc
Class RootServerPluginClassLoader

java.lang.Object
  java.lang.ClassLoader
      java.security.SecureClassLoader
          java.net.URLClassLoader
              org.rhq.enterprise.server.plugin.pc.RootServerPluginClassLoader

public class RootServerPluginClassLoader
extends URLClassLoader

This is the classloader that will be the parent to all plugin classloaders. It will be created such that it essentially hides a set of excluded classes which typically means this this root classloader (and its children plugin classloaders) will allow the following to be loaded:

• the plugin itself (including its third-party libraries)
• core plugin container libraries required by all plugins, such as plugin API classes
• plugin container jars that are configured to be unhidden

Author:

John Mazzitelli

Constructor Summary

RootServerPluginClassLoader(URL[] urls, ClassLoader parent, String... classesToHideRegexStr)
Creates this classloader.

Method Summary

URL	getResource(String name)
protected Class<?>	loadClass(String name, boolean resolve)

Methods inherited from class java.net.URLClassLoader

addURL, 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, getPackage, getPackages, getParent, 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

RootServerPluginClassLoader

public RootServerPluginClassLoader(URL[] urls,
                                   ClassLoader parent,
                                   String... classesToHideRegexStr)

Creates this classloader. classesToHideRegexStr is a regular expression to use to match against names of classes to hide (i.e. not load). If a class that is to be loaded doesn't match the regex, it will be loaded using parent-first semantics (i.e. it will first be searched in the parent classloader, and only if it isn't found there will this classloader be checked for it). Otherwise, the class will be loaded using this classloader only - the parent classloader will not be consulted so if this classloader does not have the class to be loaded, a ClassCastException will be thrown.

Parameters:

urls - URLs to jar files where classes can be loaded by this classloader

parent - the parent to this classloader, used when loading classes via parent-first semantics

classesToHideRegexStr - regular expression(s) to use to match against names of classes to load. if null or empty, no classes will be hidden, the parent will always be consulted first to load the classes.

Throws:

PatternSyntaxException - if the given regex is invalid (see Pattern.compile(String))

Method Detail

loadClass

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

Overrides:

loadClass in class ClassLoader

Throws:

ClassNotFoundException

getResource

public URL getResource(String name)

Overrides:

getResource in class ClassLoader