java.rmi.server
Class RMIClassLoaderSpi

java.lang.Object
  java.rmi.server.RMIClassLoaderSpi

public abstract class RMIClassLoaderSpi

extends Object

RMIClassLoaderSpi is the service provider interface for RMIClassLoader. In particular, an RMIClassLoaderSpi instance provides an implementation of the following static methods of RMIClassLoader:

• RMIClassLoader.loadClass(URL,String)
• RMIClassLoader.loadClass(String,String)
• RMIClassLoader.loadClass(String,String,ClassLoader)
• RMIClassLoader.loadProxyClass(String,String[],ClassLoader)
• RMIClassLoader.getClassLoader(String)
• RMIClassLoader.getClassAnnotation(Class)

When one of those methods is invoked, its behavior is to delegate to a corresponding method on an instance of this class. The details of how each method delegates to the provider instance is described in the documentation for each particular method. See the documentation for RMIClassLoader for a description of how a provider instance is chosen.

Since:

JDK1.4

Author:

Peter Jones, Laird Dornin

See Also:

RMIClassLoader

Constructor Summary

RMIClassLoaderSpi()

Method Summary

abstract String	getClassAnnotation(Class cl) Provides the implementation for RMIClassLoader.getClassAnnotation(Class).
abstract ClassLoader	getClassLoader(String codebase) Provides the implementation for RMIClassLoader.getClassLoader(String).
abstract Class	loadClass(String codebase, String name, ClassLoader defaultLoader) Provides the implementation for RMIClassLoader.loadClass(URL,String), RMIClassLoader.loadClass(String,String), and RMIClassLoader.loadClass(String,String,ClassLoader).
abstract Class	loadProxyClass(String codebase, String[] interfaces, ClassLoader defaultLoader) Provides the implementation for RMIClassLoader.loadProxyClass(String,String[],ClassLoader).

Methods inherited from class java.lang.Object

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

Constructor Detail

RMIClassLoaderSpi

public RMIClassLoaderSpi()

Method Detail

loadClass

public abstract Class loadClass(String codebase,
                                String name,
                                ClassLoader defaultLoader)
                         throws MalformedURLException,
                                ClassNotFoundException

Provides the implementation for RMIClassLoader.loadClass(URL,String), RMIClassLoader.loadClass(String,String), and RMIClassLoader.loadClass(String,String,ClassLoader). Loads a class from a codebase URL path, optionally using the supplied loader. Typically, a provider implementation will attempt to resolve the named class using the given defaultLoader, if specified, before attempting to resolve the class from the codebase URL path.

An implementation of this method must either return a class with the given name or throw an exception.

Parameters:

codebase - the list of URLs (separated by spaces) to load the class from, or null

name - the name of the class to load

defaultLoader - additional contextual class loader to use, or null

Returns:

the Class object representing the loaded class

Throws:

MalformedURLException - if codebase is non-null and contains an invalid URL, or if codebase is null and the system property java.rmi.server.codebase contains an invalid URL

ClassNotFoundException - if a definition for the class could not be found at the specified location

loadProxyClass

public abstract Class loadProxyClass(String codebase,
                                     String[] interfaces,
                                     ClassLoader defaultLoader)
                              throws MalformedURLException,
                                     ClassNotFoundException

Provides the implementation for RMIClassLoader.loadProxyClass(String,String[],ClassLoader). Loads a dynamic proxy class (see Proxy that implements a set of interfaces with the given names from a codebase URL path, optionally using the supplied loader.

An implementation of this method must either return a proxy class that implements the named interfaces or throw an exception.

Parameters:

codebase - the list of URLs (space-separated) to load classes from, or null

interfaces - the names of the interfaces for the proxy class to implement

defaultLoader - additional contextual class loader to use, or null

Returns:

a dynamic proxy class that implements the named interfaces

Throws:

MalformedURLException - if codebase is non-null and contains an invalid URL, or if codebase is null and the system property java.rmi.server.codebase contains an invalid URL

ClassNotFoundException - if a definition for one of the named interfaces could not be found at the specified location, or if creation of the dynamic proxy class failed (such as if Proxy.getProxyClass(ClassLoader,Class[]) would throw an IllegalArgumentException for the given interface list)

getClassLoader

public abstract ClassLoader getClassLoader(String codebase)
                                    throws MalformedURLException

Provides the implementation for RMIClassLoader.getClassLoader(String). Returns a class loader that loads classes from the given codebase URL path.

If there is a security manger, its checkPermission method will be invoked with a RuntimePermission("getClassLoader") permission; this could result in a SecurityException. The implementation of this method may also perform further security checks to verify that the calling context has permission to connect to all of the URLs in the codebase URL path.

Parameters:

codebase - the list of URLs (space-separated) from which the returned class loader will load classes from, or null

Returns:

a class loader that loads classes from the given codebase URL path

Throws:

MalformedURLException - if codebase is non-null and contains an invalid URL, or if codebase is null and the system property java.rmi.server.codebase contains an invalid URL

SecurityException - if there is a security manager and the invocation of its checkPermission method fails, or if the caller does not have permission to connect to all of the URLs in the codebase URL path

getClassAnnotation

public abstract String getClassAnnotation(Class cl)

Provides the implementation for RMIClassLoader.getClassAnnotation(Class). Returns the annotation string (representing a location for the class definition) that RMI will use to annotate the class descriptor when marshalling objects of the given class.

Parameters:

cl - the class to obtain the annotation for

Returns:

a string to be used to annotate the given class when it gets marshalled, or null

Throws:

NullPointerException - if cl is null