/*
* 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.io.ObjectInputFilter;
import java.rmi.*;
import sun.rmi.server.UnicastServerRef;
import sun.rmi.server.UnicastServerRef2;
import sun.rmi.transport.LiveRef;
/**
* 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 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 eight 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.
*
* <li>Calling the
* {@link #exportObject(Remote, int, ObjectInputFilter) exportObject(Remote, port, filter)} method.
*
* <li>Calling the
* {@link #exportObject(Remote, int, RMIClientSocketFactory, RMIServerSocketFactory, ObjectInputFilter)
* exportObject(Remote, port, csf, ssf, filter)} method.
*
* </ol>
*
* <p>The fourth technique, {@link #exportObject(Remote)},
* always uses statically generated stubs and is deprecated.
*
* <p>The other 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>
*
* <p>
* Exported remote objects receive method invocations from the stubs
* as described in the RMI specification. Each invocation's operation and
* parameters are unmarshaled using a custom {@link java.io.ObjectInputStream}.
* If an {@link ObjectInputFilter} is provided and is not {@code null} when the object
* is exported, it is used to filter the parameters as they are unmarshaled from the stream.
* The filter is used for all invocations and all parameters regardless of
* the method being invoked or the parameter values.
* If no filter is provided or is {@code null} for the exported object then the
* {@code ObjectInputStream} default filter, if any, is used. The default filter is
* configured with {@link ObjectInputFilter.Config#setSerialFilter(ObjectInputFilter)
* ObjectInputFilter.Config.setSerialFilter}.
* If the filter rejects any of the parameters, the {@code InvalidClassException}
* thrown by {@code ObjectInputStream} is reported as the cause of an
* {@link UnmarshalException}.
*
* @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 1.1
**/
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 1.1
*/
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 1.1
*/
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 1.1
* @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));
}
/**
* Exports the remote object to make it available to receive incoming
* calls, using the particular supplied port
* and {@linkplain ObjectInputFilter filter}.
*
* <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
* @param filter an ObjectInputFilter applied when deserializing invocation arguments;
* may be {@code null}
* @return remote object stub
* @exception RemoteException if export fails
* @since 9
*/
public static Remote exportObject(Remote obj, int port,
ObjectInputFilter filter)
throws RemoteException
{
return exportObject(obj, new UnicastServerRef(new LiveRef(port), filter));
}
/**
* Exports the remote object to make it available to receive incoming
* calls, using a transport specified by the given socket factory
* and {@linkplain ObjectInputFilter filter}.
*
* <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
* @param filter an ObjectInputFilter applied when deserializing invocation arguments;
* may be {@code null}
* @return remote object stub
* @exception RemoteException if export fails
* @since 9
*/
public static Remote exportObject(Remote obj, int port,
RMIClientSocketFactory csf,
RMIServerSocketFactory ssf,
ObjectInputFilter filter)
throws RemoteException
{
return exportObject(obj, new UnicastServerRef2(port, csf, ssf, filter));
}
/**
* 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);
}
}