org.dvb.lang

Class DVBClassLoader

java.lang.Object

java.lang.ClassLoader

java.security.SecureClassLoader

org.dvb.lang.DVBClassLoader

public abstract class DVBClassLoader
extends SecureClassLoader

This class loader is used to load classes and resources from a search path of URLs referring to locations where Java class files may be stored.

The classes that are loaded are by default only allowed to load code through the parent classloader, or from the URLs specified when the DVBClassLoader was created.

Constructor Summary

Constructors

Constructor and Description
DVBClassLoader(URL[] urls) Constructs a new DVBClassLoader for the given URLs.
DVBClassLoader(URL[] urls, ClassLoader parent) Constructs a new DVBClassLoader for the given URLs.

Method Summary

Methods

Modifier and Type	Method and Description
protected Class	findClass(String name) Finds and loads the class with the specified name from the URL search path.
static DVBClassLoader	newInstance(URL[] urls) Creates a new instance of DVBClassLoader for the specified URLs.
static DVBClassLoader	newInstance(URL[] urls, ClassLoader parent) Creates a new instance of DVBClassLoader for the specified URLs.

Methods inherited from class java.security.SecureClassLoader

defineClass, defineClass, getPermissions

Methods inherited from class java.lang.ClassLoader

clearAssertionStatus, defineClass, defineClass, defineClass, defineClass, definePackage, findLibrary, findLoadedClass, findResource, findResources, findSystemClass, getClassLoadingLock, getPackage, getPackages, getParent, getResource, getResourceAsStream, 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

Constructor Detail

DVBClassLoader

public DVBClassLoader(URL[] urls)

Constructs a new DVBClassLoader for the given URLs. The URLs will be searched in the order specified for classes and resources.

If there is a security manager, this method first calls the security manager's checkCreateClassLoader method to ensure creation of a class loader is allowed.

Parameters:

urls - the URLs from which to load classes and resources

Throws:

SecurityException - if a security manager exists and its checkCreateClassLoader method does not allow creation of a class loader.

See Also:

SecurityManager.checkCreateClassLoader()

DVBClassLoader

public DVBClassLoader(URL[] urls,
              ClassLoader parent)

Constructs a new DVBClassLoader for the given URLs. The URLs will be searched in the order specified for classes and resources.

If there is a security manager, this method first calls the security manager's checkCreateClassLoader method to ensure creation of a class loader is allowed.

Parameters:

urls - the URLs from which to load classes and resources

parent - the parent classloader for delegation

Throws:

SecurityException - if a security manager exists and its checkCreateClassLoader method does not allow creation of a class loader.

See Also:

SecurityManager.checkCreateClassLoader()

Method Detail

findClass

protected Class findClass(String name)
                   throws ClassNotFoundException

Finds and loads the class with the specified name from the URL search path. Any URLs are searched until the class is found.

Overrides:

findClass in class ClassLoader

Parameters:

name - the name of the class.

Returns:

the resulting class.

Throws:

ClassNotFoundException - if the named class could not be found.

newInstance

public static DVBClassLoader newInstance(URL[] urls)

Creates a new instance of DVBClassLoader for the specified URLs. If a security manager is installed, the loadClass method of the DVBClassLoader returned by this method will invoke the SecurityManager.checkPackageAccess method before loading the class.

Parameters:

urls - the URLs to search for classes and resources.

Returns:

the resulting class loader

newInstance

public static DVBClassLoader newInstance(URL[] urls,
                         ClassLoader parent)

Creates a new instance of DVBClassLoader for the specified URLs. If a security manager is installed, the loadClass method of the DVBClassLoader returned by this method will invoke the SecurityManager.checkPackageAccess method before loading the class.

Parameters:

urls - the URLs to search for classes and resources.

parent - the parent class loader for delegation.

Returns:

the resulting class loader