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Java example source code file (Util.java)

This example Java source code file (Util.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, getorbpropertiesfileaction, initialize, malformedurlexception, net, network, object, properties, remoteexception, rmi, security, string, util, utilclasskey, valuehandler

The Util.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 java.rmi.RemoteException;

import org.omg.CORBA.ORB;
import org.omg.CORBA.INITIALIZE;
import org.omg.CORBA.SystemException;
import org.omg.CORBA.Any;
import org.omg.CORBA.portable.InputStream;
import org.omg.CORBA.portable.OutputStream;
import org.omg.CORBA.portable.ObjectImpl;

import javax.rmi.CORBA.Tie;
import java.rmi.Remote;
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;

/**
 * Provides utility methods that can be used by stubs and ties to
 * perform common operations.
 */
public class Util {

    // This can only be set at static initialization time (no sync necessary).
    private static final javax.rmi.CORBA.UtilDelegate utilDelegate;
    private static final String UtilClassKey = "javax.rmi.CORBA.UtilClass";

    static {
        utilDelegate = (javax.rmi.CORBA.UtilDelegate)createDelegate(UtilClassKey);
    }

    private Util(){}

    /**
     * Maps a SystemException to a RemoteException.
     * @param ex the SystemException to map.
     * @return the mapped exception.
     */
    public static RemoteException mapSystemException(SystemException ex) {

        if (utilDelegate != null) {
            return utilDelegate.mapSystemException(ex);
        }
        return null;
    }

    /**
     * Writes any java.lang.Object as a CORBA any.
     * @param out the stream in which to write the any.
     * @param obj the object to write as an any.
     */
    public static void writeAny(OutputStream out, Object obj) {

        if (utilDelegate != null) {
            utilDelegate.writeAny(out, obj);
        }
    }

    /**
     * Reads a java.lang.Object as a CORBA any.
     * @param in the stream from which to read the any.
     * @return the object read from the stream.
     */
    public static Object readAny(InputStream in) {

        if (utilDelegate != null) {
            return utilDelegate.readAny(in);
        }
        return null;
    }

    /**
     * Writes a java.lang.Object as a CORBA Object. If <code>obj is
     * an exported RMI-IIOP server object, the tie is found
     * and wired to <code>obj, then written to
<code>out.write_Object(org.omg.CORBA.Object).
     * If <code>obj is a CORBA Object, it is written to
     * <code>out.write_Object(org.omg.CORBA.Object).
     * @param out the stream in which to write the object.
     * @param obj the object to write.
     */
    public static void writeRemoteObject(OutputStream out,
                                         java.lang.Object obj) {

        if (utilDelegate != null) {
            utilDelegate.writeRemoteObject(out, obj);
        }

    }

    /**
     * Writes a java.lang.Object as either a value or a CORBA Object.
     * If <code>obj is a value object or a stub object, it is written to
     * <code>out.write_abstract_interface(java.lang.Object). If obj
is
an exported
     * RMI-IIOP server object, the tie is found and wired to <code>obj,
     * then written to <code>out.write_abstract_interface(java.lang.Object).
     * @param out the stream in which to write the object.
     * @param obj the object to write.
     */
    public static void writeAbstractObject(OutputStream out,
                                           java.lang.Object obj) {

        if (utilDelegate != null) {
            utilDelegate.writeAbstractObject(out, obj);
        }
    }

    /**
     * Registers a target for a tie. Adds the tie to an internal table and calls
     * {@link Tie#setTarget} on the tie object.
     * @param tie the tie to register.
     * @param target the target for the tie.
     */
    public static void registerTarget(javax.rmi.CORBA.Tie tie,
                                      java.rmi.Remote target) {

        if (utilDelegate != null) {
            utilDelegate.registerTarget(tie, target);
        }

    }

    /**
     * Removes the associated tie from an internal table and calls {@link
Tie#deactivate}
     * to deactivate the object.
     * @param target the object to unexport.
     */
    public static void unexportObject(java.rmi.Remote target)
        throws java.rmi.NoSuchObjectException
    {

        if (utilDelegate != null) {
            utilDelegate.unexportObject(target);
        }

    }

    /**
     * Returns the tie (if any) for a given target object.
     * @return the tie or null if no tie is registered for the given target.
     */
    public static Tie getTie (Remote target) {

        if (utilDelegate != null) {
            return utilDelegate.getTie(target);
        }
        return null;
    }


    /**
     * Returns a singleton instance of a class that implements the
     * {@link ValueHandler} interface.
     * @return a class which implements the ValueHandler interface.
     */
    public static ValueHandler createValueHandler() {

        if (utilDelegate != null) {
            return utilDelegate.createValueHandler();
        }
        return null;
    }

    /**
     * Returns the codebase, if any, for the given class.
     * @param clz the class to get a codebase for.
     * @return a space-separated list of URLs, or null.
     */
    public static String getCodebase(java.lang.Class clz) {
        if (utilDelegate != null) {
            return utilDelegate.getCodebase(clz);
        }
        return null;
    }

    /**
     * Returns a class instance for the specified class.
     * <P>The spec for this method is the "Java to IDL language
     * mapping", ptc/00-01-06.
     * <P>In Java SE Platform, this method works as follows:
     * <UL>
  • Find the first non-null ClassLoader on the * call stack and attempt to load the class using this * <tt>ClassLoader. * <LI>If the first step fails, and if remoteCodebase * is non-null and * <tt>useCodebaseOnly is false, then call * <tt>java.rmi.server.RMIClassLoader.loadClass(remoteCodebase, className). * <LI>If remoteCodebase is null or useCodebaseOnly * is true, then call <tt>java.rmi.server.RMIClassLoader.loadClass(className). * <LI>If a class was not successfully loaded by step 1, 2, or 3, * and <tt>loader is non-null, then call loader.loadClass(className). * <LI>If a class was successfully loaded by step 1, 2, 3, or 4, then * return the loaded class, else throw <tt>ClassNotFoundException. * @param className the name of the class. * @param remoteCodebase a space-separated list of URLs at which * the class might be found. May be null. * @param loader a <tt>ClassLoader that may be used to * load the class if all other methods fail. * @return the <code>Class object representing the loaded class. * @exception ClassNotFoundException if class cannot be loaded. */ public static Class loadClass(String className, String remoteCodebase, ClassLoader loader) throws ClassNotFoundException { if (utilDelegate != null) { return utilDelegate.loadClass(className,remoteCodebase,loader); } return null ; } /** * The <tt>isLocal method has the same semantics as the * <tt>ObjectImpl._is_local * method, except that it can throw a <tt>RemoteException. * * The <tt>_is_local() method is provided so that stubs may determine if a * particular object is implemented by a local servant and hence local * invocation APIs may be used. * * @param stub the stub to test. * * @return The <tt>_is_local() method returns true if * the servant incarnating the object is located in the same process as * the stub and they both share the same ORB instance. The <tt>_is_local() * method returns false otherwise. The default behavior of <tt>_is_local() is * to return false. * * @throws RemoteException The Java to IDL specification does not * specify the conditions that cause a <tt>RemoteException to be thrown. */ public static boolean isLocal(Stub stub) throws RemoteException { if (utilDelegate != null) { return utilDelegate.isLocal(stub); } return false; } /** * Wraps an exception thrown by an implementation * method. It returns the corresponding client-side exception. * @param orig the exception to wrap. * @return the wrapped exception. */ public static RemoteException wrapException(Throwable orig) { if (utilDelegate != null) { return utilDelegate.wrapException(orig); } return null; } /** * Copies or connects an array of objects. Used by local stubs * to copy any number of actual parameters, preserving sharing * across parameters as necessary to support RMI semantics. * @param obj the objects to copy or connect. * @param orb the ORB. * @return the copied or connected objects. * @exception RemoteException if any object could not be copied or connected. */ public static Object[] copyObjects (Object[] obj, ORB orb) throws RemoteException { if (utilDelegate != null) { return utilDelegate.copyObjects(obj, orb); } return null; } /** * Copies or connects an object. Used by local stubs to copy * an actual parameter, result object, or exception. * @param obj the object to copy. * @param orb the ORB. * @return the copy or connected object. * @exception RemoteException if the object could not be copied or connected. */ public static Object copyObject (Object obj, ORB orb) throws RemoteException { if (utilDelegate != null) { return utilDelegate.copyObject(obj, orb); } return null; } // 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 Stub.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.Util(); } 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()); } }
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