net.grinder.util

Class BlockingClassLoader

java.lang.Object

java.lang.ClassLoader

java.security.SecureClassLoader

java.net.URLClassLoader

net.grinder.util.BlockingClassLoader

All Implemented Interfaces:

Closeable, AutoCloseable

public class BlockingClassLoader
extends URLClassLoader

Class loader that selectively ignores its parents, allowing alternative implementations of classes to be loaded.

Author:

Philip Aston

Constructor Summary

Constructors

Constructor and Description
BlockingClassLoader(List<URL> additionalClassPath, Set<String> blocked, Set<String> isolated, Set<String> shared, boolean respectGrandparents) Simplified constructor that uses standard application classloader as the parent.
BlockingClassLoader(Set<String> blocked, Set<String> isolated, Set<String> shared, boolean respectGrandparents) Simplified constructor without additionalClassPath.
BlockingClassLoader(URLClassLoader parent, List<URL> additionalClassPath, Set<String> blocked, Set<String> isolated, Set<String> shared, boolean respectGrandparents) Constructor.

Method Summary

Methods

Modifier and Type	Method and Description
URL	getResource(String name) Override only to check parent ClassLoader if not blocked.
Enumeration<URL>	getResources(String name) Override only to check parent ClassLoader if not blocked.
protected Class<?>	loadClass(String name, boolean resolve) Override only to check parent ClassLoader if not blocked.

Methods inherited from class java.net.URLClassLoader

addURL, close, definePackage, findClass, findResource, findResources, getPermissions, getResourceAsStream, 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, 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

BlockingClassLoader

public BlockingClassLoader(URLClassLoader parent,
                   List<URL> additionalClassPath,
                   Set<String> blocked,
                   Set<String> isolated,
                   Set<String> shared,
                   boolean respectGrandparents)

Constructor.

The behaviour is determined by three sets of class names. Each set contains fully qualified class names, or fully qualified prefixes ending in "*", that identify the classes beginning with the package prefix.

Resource names may also be specified, fully qualified with '/' separators as necessary. Wild card package names also filter resources; the '.' separators are translated internally to '/'s.

If multiple sets refer to the same class, shared has priority over blocked, and both have priority over isolated, whether or not the class is specified explicitly or using a package prefix.

Parameters:

parent - Parent classloader.

additionalClassPath - Prepended to the parent's URLs to calculate the classpath for this class loader.

blocked - Classes to block, whether or not the parent class loader has its own copies.

isolated - Classes to load in this class loader, whether or not the parent class loader has its own copies.

shared - Classes that should be loaded by the parent class loader, overriding blocked and isolated.

respectGrandparents - Only block or isolate classes from the parent class loader.

BlockingClassLoader

public BlockingClassLoader(List<URL> additionalClassPath,
                   Set<String> blocked,
                   Set<String> isolated,
                   Set<String> shared,
                   boolean respectGrandparents)

Simplified constructor that uses standard application classloader as the parent.

Parameters:

additionalClassPath - Prepended to the parent's URLs to calculate the classpath for this class loader.

blocked - Classes to block, whether or not the parent class loader has its own copies.

isolated - Classes to load in this class loader, whether or not the parent class loader has its own copies.

shared - Classes that should be loaded by the parent class loader, overriding blocked and isolated.

respectGrandparents - Only block or isolate classes from the parent class loader.

BlockingClassLoader

public BlockingClassLoader(Set<String> blocked,
                   Set<String> isolated,
                   Set<String> shared,
                   boolean respectGrandparents)

Simplified constructor without additionalClassPath.

Parameters:

blocked - Classes to block, whether or not the parent class loader has its own copies.

isolated - Classes to load in this class loader, whether or not the parent class loader has its own copies.

shared - Classes that should be loaded by the parent class loader, overriding blocked and isolated.

respectGrandparents - Only block or isolate classes from the parent class loader.

Method Detail

loadClass

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

Override only to check parent ClassLoader if not blocked.

Overrides:

loadClass in class ClassLoader

Throws:

ClassNotFoundException

getResource

public URL getResource(String name)

Override only to check parent ClassLoader if not blocked.

Overrides:

getResource in class ClassLoader

getResources

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

Override only to check parent ClassLoader if not blocked.

Overrides:

getResources in class ClassLoader

Throws:

IOException