rmi/CORBA/StubDelegateImpl.java

/* StubDelegateImpl.java --
   Copyright (C) 2002, 2004, 2005 Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
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General Public License for more details.

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Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA.

Linking this library statically or dynamically with other modules is
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As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
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package gnu.javax.rmi.CORBA;

import gnu.CORBA.ObjectCreator;
import gnu.CORBA.Unexpected;
import gnu.CORBA.CDR.BufferredCdrInput;
import gnu.CORBA.CDR.BufferedCdrOutput;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.rmi.Remote;
import java.rmi.RemoteException;

import javax.rmi.PortableRemoteObject;
import javax.rmi.CORBA.Stub;
import javax.rmi.CORBA.StubDelegate;
import javax.rmi.CORBA.Tie;
import javax.rmi.CORBA.Util;

import org.omg.CORBA.BAD_PARAM;
import org.omg.CORBA.ORB;
import org.omg.CORBA.portable.Delegate;
import org.omg.CORBA.portable.ObjectImpl;
import org.omg.PortableServer.POA;
import org.omg.PortableServer.POAHelper;
import org.omg.PortableServer.Servant;
import org.omg.PortableServer.POAManagerPackage.State;

/**
 * The default stub delegate.
 *
 * @author Wu Gansha (gansha.wu@intel.com) (stub)
 * @author Audrius Meskauskas (AudriusA@Bioinformatics.org) (implementation)
 */
public class StubDelegateImpl
  implements StubDelegate
{
  /**
   * <p>
   * Finds the suitable {@link Tie} for this Stub and connects it to the given
   * ORB. The tie is found by the name pattern. If the found tie is derived from
   * {@link org.omg.CORBA.PortableServer.Servant}, it is connected to the root
   * POA, also activating it (if not already active).
   * </p>
   * <p>
   * This method does not allow to specify, to which POA the found Tie must be
   * connected and requires to use the deprecated method {@link ORB#connect}.
   * Many useful POA features remain unaccessible. A better alternative it might
   * be to generate a {@link org.omg.CORBA.PortableServer.Servant} - derived Tie
   * (-poa key in rmic) and connect it to POA in one of the many ways, listed in
   * the description of the {@link orb.omg.PortableServer} package). The
   * obtained CORBA object can be narrowed into stub using
   * {@link PortableRemoteObject#narrow}.
   * </p>
   *
   * @param orb the ORB where the Stub must be connected.
   *
   * @throws RemoteException if the stub is already connected to some other ORB.
   * If the stub is already connected to the ORB that was passed as parameter,
   * the method returns without action.
   *
   * @throws BAD_PARAM if the name of this stub does not match the stub name
   * pattern, "_*_Stub" or if the Tie class, "_*Impl_Tie", does not exists or an
   * instance of this class cannot be instantiated.
   */
  public void connect(Stub self, ORB orb)
    throws RemoteException
  {
    connect(self, orb, null);
  }

  /**
   * Connect when the POA is specified.
   */
  public static void connect(Stub self, ORB orb, POA poa)
    throws RemoteException
  {
    ORB oorb = null;
    try
      {
        Delegate d = self._get_delegate();
        if (d != null)
          oorb = d.orb(self);
      }
    catch (Exception e)
      {
        // Failed to get Delegate or ORB.
        // (possible ony for user-written Stubs).
      }

    if (oorb != null)
      {
        if (!oorb.equals(orb))
          throw new RemoteException("Stub " + self
            + " is connected to another ORB, " + orb);
        else
          return;
      }

    Tie t = null;
    if (self instanceof Remote)
      t = Util.getTie((Remote) self);

    // Find by name pattern.
    if (t == null)
      t = getTieFromStub(self);

    Delegate delegate;

    if (t instanceof Servant)
      {
        try
          {
            if (poa == null)
              {
                poa = POAHelper.narrow(orb.resolve_initial_references("RootPOA"));
                // Activate if not active.
                if (poa.the_POAManager().get_state().value() == State._HOLDING)
                  poa.the_POAManager().activate();
              }

            ObjectImpl obj = (ObjectImpl) poa.servant_to_reference((Servant) t);
            delegate = obj._get_delegate();
          }
        catch (Exception ex)
          {
            throw new Unexpected(ex);
          }
      }
    else if (t instanceof ObjectImpl)
      {
        ObjectImpl o = (ObjectImpl) t;
        orb.connect(o);
        delegate = o._get_delegate();
      }
    else
      throw new BAD_PARAM("The Tie must be either Servant or ObjectImpl");

    self._set_delegate(delegate);
  }

  /**
   * Locate a tie class, appropriate to the given stub class, by the name
   * pattern.
   */
  public static Tie getTieFromStub(java.lang.Object self)
  {
    Tie t;
    String sn = self.getClass().getName();
    if (!sn.endsWith("_Stub"))
      throw new BAD_PARAM("The stub name, " + sn
        + ", does not match _*_Stub pattern");

    String tn = sn.substring(0, sn.length() - "_Stub".length()) + "Impl_Tie";
    Class tieClass = null;

    try
      {
        tieClass = ObjectCreator.forName(tn);
        t = (Tie) tieClass.newInstance();
        if (self instanceof Remote)
          Util.registerTarget(t, (Remote) self);
      }
    catch (Exception e)
      {
        BAD_PARAM bad = new BAD_PARAM("Unable to instantiate '" + tn + "'");
        bad.initCause(e);
        throw bad;
      }
    return t;
  }

  /**
   * Compare two stubs for equality.
   */
  public boolean equals(Stub self, java.lang.Object obj)
  {
    if (obj instanceof ObjectImpl)
      {
        ObjectImpl other = (ObjectImpl) obj;
        Delegate d1 = other._get_delegate();
        Delegate d2 = self._get_delegate();
        if (d1 == null || d2 == null)
          return d1 == d2;
        else
          return d1.equals(d2);
      }
    else return false;
  }

  /**
   * Get the hash code (from IOR reference).
   */
  public int hashCode(Stub self)
  {
    Delegate d = self._get_delegate();
    return d==null?0:d.hashCode();
  }

  /**
   * Returns the IOR reference of the connected ORB.
   *
   * @see ORB#object_to_string(org.omg.CORBA.Object);
   */
  public String toString(Stub self)
  {
    try
      {
        return self._orb().object_to_string(self);
      }
    catch (Exception ex)
      {
        return null;
      }
  }

  /**
   * This should never be called. The ORB must be supplied.
   *
   * @see #connect
   */
  public void readObject(Stub self, ObjectInputStream input)
    throws IOException, ClassNotFoundException
  {
    readObject(self, input, null);
  }

  /**
   * Read as CORBA object when the ORB is known. The ORB must be set under the
   * previous call of Stub.connect. The Stub is automatically registered with
   * this ORB.
   */
  public void readObject(Stub self, ObjectInputStream input, ORB orb)
    throws IOException, ClassNotFoundException
  {
    byte[] b = (byte[]) input.readObject();
    BufferredCdrInput in = new BufferredCdrInput(b);

    if (orb != null)
      in.setOrb(orb);

    ObjectImpl r = (ObjectImpl) in.read_Object();

    self._set_delegate(r._get_delegate());
  }

  /**
   * Write as CORBA object. The ORB is taken from the
   * org.omg.CORBA.portable.Delegate. The Stub is automatically registered with
   * this ORB (if not already done).
   */
  public void writeObject(Stub self, ObjectOutputStream output)
    throws IOException
  {
    writeObject(self, output, null);
  }

  /**
   * Write as CORBA object. The ORB must be either set under the previous call
   * of Stub.connect or it is taken from the org.omg.CORBA.portable.Delegate.
   * The Stub is automatically registered with this ORB (if not already done).
   */
  public void writeObject(Stub self, ObjectOutputStream output, ORB orb)
    throws IOException
  {
    BufferedCdrOutput out = new BufferedCdrOutput();
    out.setOrb(orb == null ? self._orb() : orb);
    out.write_Object(self);

    output.writeObject(out.buffer.toByteArray());
  }
}