/*

 * 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

 * particular file as subject to the "Classpath" exception as provided

 *

 * 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.

 *

 */

/*

 * Licensed Materials - Property of IBM

 * RMI-IIOP v1.0

 * Copyright IBM Corp. 1998 1999  All Rights Reserved

 *

 */

package javax.rmi.CORBA;

import org.omg.CORBA.ORB;

import org.omg.CORBA.INITIALIZE;

import org.omg.CORBA_2_3.portable.ObjectImpl;

import java.io.IOException;

import java.rmi.RemoteException;

import java.io.File;

import java.io.FileInputStream;

import java.net.MalformedURLException ;

import java.security.AccessController;

import java.security.PrivilegedAction;

import java.util.Properties;

import java.rmi.server.RMIClassLoader;

import com.sun.corba.se.impl.orbutil.GetPropertyAction;

/**

 * Base class from which all RMI-IIOP stubs must inherit.

 */

public abstract class Stub extends ObjectImpl

    implements java.io.Serializable {

    private static final long serialVersionUID = 1087775603798577179L;

    // This can only be set at object construction time (no sync necessary).

    private transient StubDelegate stubDelegate = null;

    private static Class stubDelegateClass = null;

    private static final String StubClassKey = "javax.rmi.CORBA.StubClass";

    private static final String defaultStubImplName = "com.sun.corba.se.impl.javax.rmi.CORBA.StubDelegateImpl";

    static {

        Object stubDelegateInstance = (Object) createDelegateIfSpecified(StubClassKey, defaultStubImplName);

        if (stubDelegateInstance != null)

            stubDelegateClass = stubDelegateInstance.getClass();

    }

    /**

     * Returns a hash code value for the object which is the same for all stubs

     * that represent the same remote object.

     * @return the hash code value.

     */

    public int hashCode() {

        if (stubDelegate == null) {

            setDefaultDelegate();

        }

        if (stubDelegate != null) {

            return stubDelegate.hashCode(this);

        }

        return 0;

    }

    /**

     * Compares two stubs for equality. Returns <code>true</code> when used to compare stubs

     * that represent the same remote object, and <code>false</code> otherwise.

     * @param obj the reference object with which to compare.

     * @return <code>true</code> if this object is the same as the <code>obj</code>

     *          argument; <code>false</code> otherwise.

     */

    public boolean equals(java.lang.Object obj) {

        if (stubDelegate == null) {

            setDefaultDelegate();

        }

        if (stubDelegate != null) {

            return stubDelegate.equals(this, obj);

        }

        return false;

    }

    /**

     * Returns a string representation of this stub. Returns the same string

     * for all stubs that represent the same remote object.

     * @return a string representation of this stub.

     */

    public String toString() {

        if (stubDelegate == null) {

            setDefaultDelegate();

        }

        String ior;

        if (stubDelegate != null) {

            ior = stubDelegate.toString(this);

            if (ior == null) {

                return super.toString();

            } else {

                return ior;

            }

        }

        return super.toString();

    }

    /**

     * Connects this stub to an ORB. Required after the stub is deserialized

     * but not after it is demarshalled by an ORB stream. If an unconnected

     * stub is passed to an ORB stream for marshalling, it is implicitly

     * connected to that ORB. Application code should not call this method

     * directly, but should call the portable wrapper method

     * {@link javax.rmi.PortableRemoteObject#connect}.

     * @param orb the ORB to connect to.

     * @exception RemoteException if the stub is already connected to a different

     * ORB, or if the stub does not represent an exported remote or local object.

     */

    public void connect(ORB orb) throws RemoteException {

        if (stubDelegate == null) {

            setDefaultDelegate();

        }

        if (stubDelegate != null) {

            stubDelegate.connect(this, orb);

        }

    }

    /**

     * Serialization method to restore the IOR state.

     */

    private void readObject(java.io.ObjectInputStream stream)

        throws IOException, ClassNotFoundException {

        if (stubDelegate == null) {

            setDefaultDelegate();

        }

        if (stubDelegate != null) {

            stubDelegate.readObject(this, stream);

        }

    }

    /**

     * Serialization method to save the IOR state.

     * @serialData The length of the IOR type ID (int), followed by the IOR type ID

     * (byte array encoded using ISO8859-1), followed by the number of IOR profiles

     * (int), followed by the IOR profiles.  Each IOR profile is written as a

     * profile tag (int), followed by the length of the profile data (int), followed

     * by the profile data (byte array).

     */

    private void writeObject(java.io.ObjectOutputStream stream) throws IOException {

        if (stubDelegate == null) {

            setDefaultDelegate();

        }

        if (stubDelegate != null) {

            stubDelegate.writeObject(this, stream);

        }

    }

    private void setDefaultDelegate() {

        if (stubDelegateClass != null) {

            try {

                 stubDelegate = (javax.rmi.CORBA.StubDelegate) stubDelegateClass.newInstance();

            } catch (Exception ex) {

            // what kind of exception to throw

            // delegate not set therefore it is null and will return default

            // values

            }

        }

    }

    // Same code as in PortableRemoteObject. Can not be shared because they

    // are in different packages and the visibility needs to be package for

    // security reasons. If you know a better solution how to share this code

    // then remove it from PortableRemoteObject. Also in Util.java

    private static Object createDelegateIfSpecified(String classKey, String defaultClassName) {

        String className = (String)

            AccessController.doPrivileged(new GetPropertyAction(classKey));

        if (className == null) {

            Properties props = getORBPropertiesFile();

            if (props != null) {

                className = props.getProperty(classKey);

            }

        }

        if (className == null) {

            className = defaultClassName;

        }

        try {

            return loadDelegateClass(className).newInstance();

        } catch (ClassNotFoundException ex) {

            INITIALIZE exc = new INITIALIZE( "Cannot instantiate " + className);

            exc.initCause( ex ) ;

            throw exc ;

        } catch (Exception ex) {

            INITIALIZE exc = new INITIALIZE( "Error while instantiating" + className);

            exc.initCause( ex ) ;

            throw exc ;

        }

    }

    private static Class loadDelegateClass( String className )  throws ClassNotFoundException

    {

        try {

            ClassLoader loader = Thread.currentThread().getContextClassLoader();

            return Class.forName(className, false, loader);

        } catch (ClassNotFoundException e) {

            // ignore, then try RMIClassLoader

        }

        try {

            return RMIClassLoader.loadClass(className);

        } catch (MalformedURLException e) {

            String msg = "Could not load " + className + ": " + e.toString();

            ClassNotFoundException exc = new ClassNotFoundException( msg ) ;

            throw exc ;

        }

    }

    /**

     * Load the orb.properties file.

     */

    private static Properties getORBPropertiesFile () {

        return (Properties) AccessController.doPrivileged(new GetORBPropertiesFileAction());

    }

}