alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Java example source code file (Stub.java)

This example Java source code file (Stub.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

cannot, classloader, classnotfoundexception, corba, could, error, getpropertyaction, initialize, ioexception, malformedurlexception, net, network, object, objectimpl, properties, rmi, security, string, stubclasskey, util

The Stub.java Java example source code

/*
 * Copyright (c) 1998, 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.
 */

/*
 * 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";

    static {
        Object stubDelegateInstance = createDelegate(StubClassKey);
        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 when used to compare stubs
     * that represent the same remote object, and <code>false otherwise.
     * @param obj the reference object with which to compare.
     * @return <code>true if this object is the same as the obj
     *          argument; <code>false 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 createDelegate(String classKey) {
        String className = (String)
            AccessController.doPrivileged(new GetPropertyAction(classKey));
        if (className == null) {
            Properties props = getORBPropertiesFile();
            if (props != null) {
                className = props.getProperty(classKey);
            }
        }

        if (className == null) {
            return new com.sun.corba.se.impl.javax.rmi.CORBA.StubDelegateImpl();
        }

        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());
    }

}

Other Java examples (source code examples)

Here is a short list of links related to this Java Stub.java source code file:

... this post is sponsored by my books ...

#1 New Release!

FP Best Seller

 

new blog posts

 

Copyright 1998-2024 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.