/*
* @(#)PortableRemoteObject.java 1.32 04/06/21
*
* Copyright 2004 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
/*
* Licensed Materials - Property of IBM
* RMI-IIOP v1.0
* Copyright IBM Corp. 1998 1999 All Rights Reserved
*
* US Government Users Restricted Rights - Use, duplication or
* disclosure restricted by GSA ADP Schedule Contract with IBM Corp.
*/
package javax.rmi;
import java.lang.reflect.Method ;
import org.omg.CORBA.INITIALIZE;
import javax.rmi.CORBA.Util;
import java.rmi.RemoteException;
import java.rmi.NoSuchObjectException;
import java.rmi.Remote;
import java.io.File;
import java.io.FileInputStream;
import java.util.Properties;
import java.net.MalformedURLException ;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.rmi.server.RMIClassLoader;
import com.sun.corba.se.impl.orbutil.GetPropertyAction;
/**
* Server implementation objects may either inherit from
* javax.rmi.PortableRemoteObject or they may implement a remote interface
* and then use the exportObject method to register themselves as a server object.
* The toStub method takes a server implementation and returns a stub that
* can be used to access that server object.
* The connect method makes a Remote object ready for remote communication.
* The unexportObject method is used to deregister a server object, allowing it to become
* available for garbage collection.
* The narrow method takes an object reference or abstract interface type and
* attempts to narrow it to conform to
* the given interface. If the operation is successful the result will be an
* object of the specified type, otherwise an exception will be thrown.
*/
public class PortableRemoteObject {
private static javax.rmi.CORBA.PortableRemoteObjectDelegate proDelegate = null;
private static final String PortableRemoteObjectClassKey =
"javax.rmi.CORBA.PortableRemoteObjectClass";
private static final String defaultPortableRemoteObjectImplName =
"com.sun.corba.se.impl.javax.rmi.PortableRemoteObject";
static {
proDelegate = (javax.rmi.CORBA.PortableRemoteObjectDelegate)
createDelegateIfSpecified(PortableRemoteObjectClassKey);
}
/**
* Initializes the object by calling <code>exportObject(this)</code>.
* @exception RemoteException if export fails.
*/
protected PortableRemoteObject() throws RemoteException {
if (proDelegate != null) {
PortableRemoteObject.exportObject((Remote)this);
}
}
/**
* Makes a server object ready to receive remote calls. Note
* that subclasses of PortableRemoteObject do not need to call this
* method, as it is called by the constructor.
* @param obj the server object to export.
* @exception RemoteException if export fails.
*/
public static void exportObject(Remote obj)
throws RemoteException {
// Let the delegate do everything, including error handling.
if (proDelegate != null) {
proDelegate.exportObject(obj);
}
}
/**
* Returns a stub for the given server object.
* @param obj the server object for which a stub is required. Must either be a subclass
* of PortableRemoteObject or have been previously the target of a call to
* {@link #exportObject}.
* @return the most derived stub for the object.
* @exception NoSuchObjectException if a stub cannot be located for the given server object.
*/
public static Remote toStub (Remote obj)
throws NoSuchObjectException {
if (proDelegate != null) {
return proDelegate.toStub(obj);
}
return null;
}
/**
* Deregisters a server object from the runtime, allowing the object to become
* available for garbage collection.
* @param obj the object to unexport.
* @exception NoSuchObjectException if the remote object is not
* currently exported.
*/
public static void unexportObject(Remote obj)
throws NoSuchObjectException {
if (proDelegate != null) {
proDelegate.unexportObject(obj);
}
}
/**
* Checks to ensure that an object of a remote or abstract interface type
* can be cast to a desired type.
* @param narrowFrom the object to check.
* @param narrowTo the desired type.
* @return an object which can be cast to the desired type.
* @throws ClassCastException if narrowFrom cannot be cast to narrowTo.
*/
public static java.lang.Object narrow ( java.lang.Object narrowFrom,
java.lang.Class narrowTo)
throws ClassCastException {
if (proDelegate != null) {
return proDelegate.narrow(narrowFrom, narrowTo);
}
return null;
}
/**
* Makes a Remote object ready for remote communication. This normally
* happens implicitly when the object is sent or received as an argument
* on a remote method call, but in some circumstances it is useful to
* perform this action by making an explicit call. See the
* {@link Stub#connect} method for more information.
* @param target the object to connect.
* @param source a previously connected object.
* @throws RemoteException if <code>source</code> is not connected
* or if <code>target</code> is already connected to a different ORB than
* <code>source</code>.
*/
public static void connect (Remote target, Remote source)
throws RemoteException {
if (proDelegate != null) {
proDelegate.connect(target, source);
}
}
// Same code as in javax.rmi.CORBA.Util. 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 here.
private static Object createDelegateIfSpecified(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) {
className = defaultPortableRemoteObjectImplName;
}
try {
return (Object) 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());
}
}
class GetORBPropertiesFileAction implements PrivilegedAction {
private boolean debug = false ;
public GetORBPropertiesFileAction () {
}
private String getSystemProperty(final String name) {
// This will not throw a SecurityException because this
// class was loaded from rt.jar using the bootstrap classloader.
String propValue = (String) AccessController.doPrivileged(
new PrivilegedAction() {
public java.lang.Object run() {
return System.getProperty(name);
}
}
);
return propValue;
}
private void getPropertiesFromFile( Properties props, String fileName )
{
try {
File file = new File( fileName ) ;
if (!file.exists())
return ;
FileInputStream in = new FileInputStream( file ) ;
try {
props.load( in ) ;
} finally {
in.close() ;
}
} catch (Exception exc) {
if (debug)
System.out.println( "ORB properties file " + fileName +
" not found: " + exc) ;
}
}
public Object run()
{
Properties defaults = new Properties() ;
String javaHome = getSystemProperty( "java.home" ) ;
String fileName = javaHome + File.separator + "lib" + File.separator +
"orb.properties" ;
getPropertiesFromFile( defaults, fileName ) ;
Properties results = new Properties( defaults ) ;
String userHome = getSystemProperty( "user.home" ) ;
fileName = userHome + File.separator + "orb.properties" ;
getPropertiesFromFile( results, fileName ) ;
return results ;
}
}
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