/*
* @(#)UnicastRemoteObject.java 1.33 05/11/17
*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
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.
*
* <p>For the constructors and static <code>exportObject</code> methods
* below, the stub for a remote object being exported is obtained as
* follows:
*
* <p><ul>
*
* <li>If the remote object is exported using the {@link
* #exportObject(Remote) UnicastRemoteObject.exportObject(Remote)} method,
* a stub class (typically pregenerated from the remote object's class
* using the <code>rmic</code> tool) is loaded and an instance of that stub
* class is constructed as follows.
* <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</code>.
*
* <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"</code>.
*
* <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}.
* </ul>
*
* <li>If the appropriate stub class could not be found, or the stub class
* could not be loaded, or a problem occurs creating the stub instance, a
* {@link StubNotFoundException} is thrown.
*
* <p>
* <li>For all other means of exporting:
* <p><ul>
*
* <li>If the remote object's stub class (as defined above) could not be
* loaded or the system property
* <code>java.rmi.server.ignoreStubClasses</code> is set to
* <code>"true"</code> (case insensitive), a {@link
* java.lang.reflect.Proxy} instance is constructed with the following
* properties:
*
* <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>
* <li>Otherwise, an instance of the remote object's stub class (as
* described above) is used as the stub.
*
* </ul>
* </ul>
*
* @version 1.33, 11/17/05
* @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.
* @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.
* @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.
* @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.
* @param obj the remote object to be exported
* @return remote object stub
* @exception RemoteException if export fails
* @since JDK1.1
*/
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.
* @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.
* @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);
}
}