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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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package java.rmi.server;
import java.net.MalformedURLException;
import java.net.URL;
/**
* <code>RMIClassLoaderSpi</code> is the service provider interface for
* <code>RMIClassLoader</code>.
*
* In particular, an <code>RMIClassLoaderSpi</code> instance provides an
* implementation of the following static methods of
* <code>RMIClassLoader</code>:
*
* <ul>
*
* <li>{@link RMIClassLoader#loadClass(URL,String)}
* <li>{@link RMIClassLoader#loadClass(String,String)}
* <li>{@link RMIClassLoader#loadClass(String,String,ClassLoader)}
* <li>{@link RMIClassLoader#loadProxyClass(String,String[],ClassLoader)}
* <li>{@link RMIClassLoader#getClassLoader(String)}
* <li>{@link RMIClassLoader#getClassAnnotation(Class)}
*
* </ul>
*
* 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 {@link RMIClassLoader} for a description
* of how a provider instance is chosen.
*
* @author Peter Jones
* @author Laird Dornin
* @see RMIClassLoader
* @since 1.4
*/
public abstract class RMIClassLoaderSpi {
/**
* Provides the implementation for
* {@link RMIClassLoader#loadClass(URL,String)},
* {@link RMIClassLoader#loadClass(String,String)}, and
* {@link 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 <code>defaultLoader</code>,
* if specified, before attempting to resolve the class from the
* codebase URL path.
*
* <p>An implementation of this method must either return a class
* with the given name or throw an exception.
*
* @param codebase the list of URLs (separated by spaces) to load
* the class from, or <code>null</code>
*
* @param name the name of the class to load
*
* @param defaultLoader additional contextual class loader
* to use, or <code>null</code>
*
* @return the <code>Class</code> object representing the loaded class
*
* @throws MalformedURLException if <code>codebase</code> is
* non-<code>null</code> and contains an invalid URL, or
* if <code>codebase</code> is <code>null</code> and a provider-specific
* URL used to load classes is invalid
*
* @throws ClassNotFoundException if a definition for the class
* could not be found at the specified location
*/
public abstract Class<?> loadClass(String codebase, String name,
ClassLoader defaultLoader)
throws MalformedURLException, ClassNotFoundException;
/**
* Provides the implementation for
* {@link RMIClassLoader#loadProxyClass(String,String[],ClassLoader)}.
*
* Loads a dynamic proxy class (see {@link java.lang.reflect.Proxy}
* that implements a set of interfaces with the given names
* from a codebase URL path, optionally using the supplied loader.
*
* <p>An implementation of this method must either return a proxy
* class that implements the named interfaces or throw an exception.
*
* @param codebase the list of URLs (space-separated) to load
* classes from, or <code>null</code>
*
* @param interfaces the names of the interfaces for the proxy class
* to implement
*
* @return a dynamic proxy class that implements the named interfaces
*
* @param defaultLoader additional contextual class loader
* to use, or <code>null</code>
*
* @throws MalformedURLException if <code>codebase</code> is
* non-<code>null</code> and contains an invalid URL, or
* if <code>codebase</code> is <code>null</code> and a provider-specific
* URL used to load classes is invalid
*
* @throws 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
* {@link java.lang.reflect.Proxy#getProxyClass(ClassLoader,Class[])}
* would throw an <code>IllegalArgumentException</code> for the given
* interface list)
*/
public abstract Class<?> loadProxyClass(String codebase,
String[] interfaces,
ClassLoader defaultLoader)
throws MalformedURLException, ClassNotFoundException;
/**
* Provides the implementation for
* {@link RMIClassLoader#getClassLoader(String)}.
*
* Returns a class loader that loads classes from the given codebase
* URL path.
*
* <p>If there is a security manger, its <code>checkPermission</code>
* method will be invoked with a
* <code>RuntimePermission("getClassLoader")</code> permission;
* this could result in a <code>SecurityException</code>.
* 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.
*
* @param codebase the list of URLs (space-separated) from which
* the returned class loader will load classes from, or <code>null</code>
*
* @return a class loader that loads classes from the given codebase URL
* path
*
* @throws MalformedURLException if <code>codebase</code> is
* non-<code>null</code> and contains an invalid URL, or
* if <code>codebase</code> is <code>null</code> and a provider-specific
* URL used to identify the class loader is invalid
*
* @throws SecurityException if there is a security manager and the
* invocation of its <code>checkPermission</code> method fails, or
* if the caller does not have permission to connect to all of the
* URLs in the codebase URL path
*/
public abstract ClassLoader getClassLoader(String codebase)
throws MalformedURLException; // SecurityException
/**
* Provides the implementation for
* {@link 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.
*
* @param cl the class to obtain the annotation for
*
* @return a string to be used to annotate the given class when
* it gets marshalled, or <code>null</code>
*
* @throws NullPointerException if <code>cl</code> is <code>null</code>
*/
public abstract String getClassAnnotation(Class<?> cl);
}