/*

 * 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 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 javax.rmi.CORBA.UtilDelegate utilDelegate = null;

    private static final String UtilClassKey = "javax.rmi.CORBA.UtilClass";

    private static final String defaultUtilImplName =

"com.sun.corba.se.impl.javax.rmi.CORBA.Util";

    static {

        utilDelegate = (javax.rmi.CORBA.UtilDelegate)

            createDelegateIfSpecified(UtilClassKey, defaultUtilImplName);

    }

    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</code> is

     * an exported RMI-IIOP server object, the tie is found

     * and wired to <code>obj</code>, then written to

<code>out.write_Object(org.omg.CORBA.Object)</code>.

     * If <code>obj</code> is a CORBA Object, it is written to

     * <code>out.write_Object(org.omg.CORBA.Object)</code>.

     * @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</code> is a value object or a stub object, it is written to

     * <code>out.write_abstract_interface(java.lang.Object)</code>. If <code>obj</code>

is

an exported

     * RMI-IIOP server object, the tie is found and wired to <code>obj</code>,

     * then written to <code>out.write_abstract_interface(java.lang.Object)</code>.

     * @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><LI>Find the first non-null <tt>ClassLoader</tt> on the

     * call stack and attempt to load the class using this

     * <tt>ClassLoader</tt>.

     * <LI>If the first step fails, and if <tt>remoteCodebase</tt>

     * is non-null and

     * <tt>useCodebaseOnly</tt> is false, then call

     * <tt>java.rmi.server.RMIClassLoader.loadClass(remoteCodebase, className)</tt>.

     * <LI>If <tt>remoteCodebase</tt> is null or <tt>useCodebaseOnly</tt>

     * is true, then call <tt>java.rmi.server.RMIClassLoader.loadClass(className)</tt>.

     * <LI>If a class was not successfully loaded by step 1, 2, or 3,

     * and <tt>loader</tt> is non-null, then call <tt>loader.loadClass(className)</tt>.

     * <LI>If a class was successfully loaded by step 1, 2, 3, or 4, then

     *  return the loaded class, else throw <tt>ClassNotFoundException</tt>.

     * @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</tt> that may be used to

     * load the class if all other methods fail.

     * @return the <code>Class</code> 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</tt> method has the same semantics as the

     * <tt>ObjectImpl._is_local</tt>

     * method, except that it can throw a <tt>RemoteException</tt>.

     *

     * The <tt>_is_local()</tt> 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()</tt> 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()</tt>

     * method returns false otherwise. The default behavior of <tt>_is_local()</tt> is

     * to return false.

     *

     * @throws RemoteException The Java to IDL specification does not

     * specify the conditions that cause a <tt>RemoteException</tt> 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 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());

    }

}