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	/*
	* Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* 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).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/
	package java.rmi.server;

	import java.rmi.*;
	import sun.rmi.server.UnicastServerRef;
	import sun.rmi.server.UnicastServerRef2;

	/**
	* Used for exporting a remote object with JRMP and obtaining a stub
	* that communicates to the remote object. Stubs are either generated
	* at runtime using dynamic proxy objects, or they are generated statically
	* at build time, typically using the {@code rmic} tool.
	*
	* <p><strong>Deprecated: Static Stubs.</strong> <em>Support for statically
	* generated stubs is deprecated. This includes the API in this class that
	* requires the use of static stubs, as well as the runtime support for
	* loading static stubs. Generating stubs dynamically is preferred, using one
	* of the five non-deprecated ways of exporting objects as listed below. Do
	* not run {@code rmic} to generate static stub classes. It is unnecessary, and
	* it is also deprecated.</em>
	*
	* <p>There are six ways to export remote objects:
	*
	* <ol>
	*
	* <li>Subclassing {@code UnicastRemoteObject} and calling the
	* {@link #UnicastRemoteObject()} constructor.
	*
	* <li>Subclassing {@code UnicastRemoteObject} and calling the
	* {@link #UnicastRemoteObject(int) UnicastRemoteObject(port)} constructor.
	*
	* <li>Subclassing {@code UnicastRemoteObject} and calling the
	* {@link #UnicastRemoteObject(int, RMIClientSocketFactory, RMIServerSocketFactory)
	* UnicastRemoteObject(port, csf, ssf)} constructor.
	*
	* <li>Calling the
	* {@link #exportObject(Remote) exportObject(Remote)} method.
	* <strong>Deprecated.</strong>
	*
	* <li>Calling the
	* {@link #exportObject(Remote, int) exportObject(Remote, port)} method.
	*
	* <li>Calling the
	* {@link #exportObject(Remote, int, RMIClientSocketFactory, RMIServerSocketFactory)
	* exportObject(Remote, port, csf, ssf)} method.
	*
	* </ol>
	*
	* <p>The fourth technique, {@link #exportObject(Remote)},
	* always uses statically generated stubs and is deprecated.
	*
	* <p>The other five techniques all use the following approach: if the
	* {@code java.rmi.server.ignoreStubClasses} property is {@code true}
	* (case insensitive) or if a static stub cannot be found, stubs are generated
	* dynamically using {@link java.lang.reflect.Proxy Proxy} objects. Otherwise,
	* static stubs are used.
	*
	* <p>The default value of the
	* {@code java.rmi.server.ignoreStubClasses} property is {@code false}.
	*
	* <p>Statically generated stubs are typically pregenerated from the
	* remote object's class using the {@code rmic} tool. A static stub is
	* loaded and an instance of that stub class is constructed as described
	* below.
	*
	* <ul>
	*
	* <li>A "root class" is determined as follows: if the remote object's
	* class directly implements an interface that extends {@link Remote}, then
	* the remote object's class is the root class; otherwise, the root class is
	* the most derived superclass of the remote object's class that directly
	* implements an interface that extends {@code Remote}.
	*
	* <li>The name of the stub class to load is determined by concatenating
	* the binary name of the root class with the suffix {@code _Stub}.
	*
	* <li>The stub class is loaded by name using the class loader of the root
	* class. The stub class must extend {@link RemoteStub} and must have a
	* public constructor that has one parameter of type {@link RemoteRef}.
	*
	* <li>Finally, an instance of the stub class is constructed with a
	* {@link RemoteRef}.
	*
	* <li>If the appropriate stub class could not be found, or if the stub class
	* could not be loaded, or if a problem occurs creating the stub instance, a
	* {@link StubNotFoundException} is thrown.
	*
	* </ul>
	*
	* <p>Stubs are dynamically generated by constructing an instance of
	* a {@link java.lang.reflect.Proxy Proxy} with the following characteristics:
	*
	* <ul>
	*
	* <li>The proxy's class is defined by the class loader of the remote
	* object's class.
	*
	* <li>The proxy implements all the remote interfaces implemented by the
	* remote object's class.
	*
	* <li>The proxy's invocation handler is a {@link
	* RemoteObjectInvocationHandler} instance constructed with a
	* {@link RemoteRef}.
	*
	* <li>If the proxy could not be created, a {@link StubNotFoundException}
	* will be thrown.
	*
	* </ul>
	*
	* @implNote
	* Depending upon which constructor or static method is used for exporting an
	* object, {@link RMISocketFactory} may be used for creating sockets.
	* By default, server sockets created by {@link RMISocketFactory}
	* listen on all network interfaces. See the
	* {@link RMISocketFactory} class and the section
	* <a href="{@docRoot}/../platform/rmi/spec/rmi-server29.html">RMI Socket Factories</a>
	* in the
	* <a href="{@docRoot}/../platform/rmi/spec/rmiTOC.html">Java RMI Specification</a>.
	*
	* @author Ann Wollrath
	* @author Peter Jones
	* @since JDK1.1
	**/
	public class UnicastRemoteObject extends RemoteServer {

	/**
	* @serial port number on which to export object
	*/
	private int port = 0;

	/**
	* @serial client-side socket factory (if any)
	*/
	private RMIClientSocketFactory csf = null;

	/**
	* @serial server-side socket factory (if any) to use when
	* exporting object
	*/
	private RMIServerSocketFactory ssf = null;

	/* indicate compatibility with JDK 1.1.x version of class */
	private static final long serialVersionUID = 4974527148936298033L;

	/**
	* Creates and exports a new UnicastRemoteObject object using an
	* anonymous port.
	*
	* <p>The object is exported with a server socket
	* created using the {@link RMISocketFactory} class.
	*
	* @throws RemoteException if failed to export object
	* @since JDK1.1
	*/
	protected UnicastRemoteObject() throws RemoteException
	{
	this(0);
	}

	/**
	* Creates and exports a new UnicastRemoteObject object using the
	* particular supplied port.
	*
	* <p>The object is exported with a server socket
	* created using the {@link RMISocketFactory} class.
	*
	* @param port the port number on which the remote object receives calls
	* (if <code>port</code> is zero, an anonymous port is chosen)
	* @throws RemoteException if failed to export object
	* @since 1.2
	*/
	protected UnicastRemoteObject(int port) throws RemoteException
	{
	this.port = port;
	exportObject((Remote) this, port);
	}

	/**
	* Creates and exports a new UnicastRemoteObject object using the
	* particular supplied port and socket factories.
	*
	* <p>Either socket factory may be {@code null}, in which case
	* the corresponding client or server socket creation method of
	* {@link RMISocketFactory} is used instead.
	*
	* @param port the port number on which the remote object receives calls
	* (if <code>port</code> is zero, an anonymous port is chosen)
	* @param csf the client-side socket factory for making calls to the
	* remote object
	* @param ssf the server-side socket factory for receiving remote calls
	* @throws RemoteException if failed to export object
	* @since 1.2
	*/
	protected UnicastRemoteObject(int port,
	RMIClientSocketFactory csf,
	RMIServerSocketFactory ssf)
	throws RemoteException
	{
	this.port = port;
	this.csf = csf;
	this.ssf = ssf;
	exportObject((Remote) this, port, csf, ssf);
	}

	/**
	* Re-export the remote object when it is deserialized.
	*/
	private void readObject(java.io.ObjectInputStream in)
	throws java.io.IOException, java.lang.ClassNotFoundException
	{
	in.defaultReadObject();
	reexport();
	}

	/**
	* Returns a clone of the remote object that is distinct from
	* the original.
	*
	* @exception CloneNotSupportedException if clone failed due to
	* a RemoteException.
	* @return the new remote object
	* @since JDK1.1
	*/
	public Object clone() throws CloneNotSupportedException
	{
	try {
	UnicastRemoteObject cloned = (UnicastRemoteObject) super.clone();
	cloned.reexport();
	return cloned;
	} catch (RemoteException e) {
	throw new ServerCloneException("Clone failed", e);
	}
	}

	/*
	* Exports this UnicastRemoteObject using its initialized fields because
	* its creation bypassed running its constructors (via deserialization
	* or cloning, for example).
	*/
	private void reexport() throws RemoteException
	{
	if (csf == null && ssf == null) {
	exportObject((Remote) this, port);
	} else {
	exportObject((Remote) this, port, csf, ssf);
	}
	}

	/**
	* Exports the remote object to make it available to receive incoming
	* calls using an anonymous port. This method will always return a
	* statically generated stub.
	*
	* <p>The object is exported with a server socket
	* created using the {@link RMISocketFactory} class.
	*
	* @param obj the remote object to be exported
	* @return remote object stub
	* @exception RemoteException if export fails
	* @since JDK1.1
	* @deprecated This method is deprecated because it supports only static stubs.
	* Use {@link #exportObject(Remote, int) exportObject(Remote, port)} or
	* {@link #exportObject(Remote, int, RMIClientSocketFactory, RMIServerSocketFactory)
	* exportObject(Remote, port, csf, ssf)}
	* instead.
	*/
	@Deprecated
	public static RemoteStub exportObject(Remote obj)
	throws RemoteException
	{
	/*
	* Use UnicastServerRef constructor passing the boolean value true
	* to indicate that only a generated stub class should be used. A
	* generated stub class must be used instead of a dynamic proxy
	* because the return value of this method is RemoteStub which a
	* dynamic proxy class cannot extend.
	*/
	return (RemoteStub) exportObject(obj, new UnicastServerRef(true));
	}

	/**
	* Exports the remote object to make it available to receive incoming
	* calls, using the particular supplied port.
	*
	* <p>The object is exported with a server socket
	* created using the {@link RMISocketFactory} class.
	*
	* @param obj the remote object to be exported
	* @param port the port to export the object on
	* @return remote object stub
	* @exception RemoteException if export fails
	* @since 1.2
	*/
	public static Remote exportObject(Remote obj, int port)
	throws RemoteException
	{
	return exportObject(obj, new UnicastServerRef(port));
	}

	/**
	* Exports the remote object to make it available to receive incoming
	* calls, using a transport specified by the given socket factory.
	*
	* <p>Either socket factory may be {@code null}, in which case
	* the corresponding client or server socket creation method of
	* {@link RMISocketFactory} is used instead.
	*
	* @param obj the remote object to be exported
	* @param port the port to export the object on
	* @param csf the client-side socket factory for making calls to the
	* remote object
	* @param ssf the server-side socket factory for receiving remote calls
	* @return remote object stub
	* @exception RemoteException if export fails
	* @since 1.2
	*/
	public static Remote exportObject(Remote obj, int port,
	RMIClientSocketFactory csf,
	RMIServerSocketFactory ssf)
	throws RemoteException
	{

	return exportObject(obj, new UnicastServerRef2(port, csf, ssf));
	}

	/**
	* Removes the remote object, obj, from the RMI runtime. If
	* successful, the object can no longer accept incoming RMI calls.
	* If the force parameter is true, the object is forcibly unexported
	* even if there are pending calls to the remote object or the
	* remote object still has calls in progress. If the force
	* parameter is false, the object is only unexported if there are
	* no pending or in progress calls to the object.
	*
	* @param obj the remote object to be unexported
	* @param force if true, unexports the object even if there are
	* pending or in-progress calls; if false, only unexports the object
	* if there are no pending or in-progress calls
	* @return true if operation is successful, false otherwise
	* @exception NoSuchObjectException if the remote object is not
	* currently exported
	* @since 1.2
	*/
	public static boolean unexportObject(Remote obj, boolean force)
	throws java.rmi.NoSuchObjectException
	{
	return sun.rmi.transport.ObjectTable.unexportObject(obj, force);
	}

	/**
	* Exports the specified object using the specified server ref.
	*/
	private static Remote exportObject(Remote obj, UnicastServerRef sref)
	throws RemoteException
	{
	// if obj extends UnicastRemoteObject, set its ref.
	if (obj instanceof UnicastRemoteObject) {
	((UnicastRemoteObject) obj).ref = sref;
	}
	return sref.exportObject(obj, null, false);
	}
	}

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