/**
* Redistribution and use of this software and associated documentation
* ("Software"), with or without modification, are permitted provided
* that the following conditions are met:
*
* 1. Redistributions of source code must retain copyright
* statements and notices. Redistributions must also contain a
* copy of this document.
*
* 2. Redistributions in binary form must reproduce the
* above copyright notice, this list of conditions and the
* following disclaimer in the documentation and/or other
* materials provided with the distribution.
*
* 3. The name "Exolab" must not be used to endorse or promote
* products derived from this Software without prior written
* permission of Exoffice Technologies. For written permission,
* please contact info@exolab.org.
*
* 4. Products derived from this Software may not be called "Exolab"
* nor may "Exolab" appear in their names without prior written
* permission of Exoffice Technologies. Exolab is a registered
* trademark of Exoffice Technologies.
*
* 5. Due credit should be given to the Exolab Project
* (http://www.exolab.org/).
*
* THIS SOFTWARE IS PROVIDED BY EXOFFICE TECHNOLOGIES AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
* NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* EXOFFICE TECHNOLOGIES OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Copyright 2003-2005 (C) Exoffice Technologies Inc. All Rights Reserved.
*
* $Id: UnicastDelegate.java,v 1.2 2005/11/16 12:32:49 tanderson Exp $
*/
package org.exolab.jms.net.orb;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.lang.reflect.Method;
import java.rmi.server.ObjID;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.exolab.jms.net.connector.Connection;
import org.exolab.jms.net.connector.ConnectionContext;
import org.exolab.jms.net.connector.ConnectionFactory;
import org.exolab.jms.net.connector.Request;
import org.exolab.jms.net.connector.ResourceException;
import org.exolab.jms.net.connector.Response;
import org.exolab.jms.net.proxy.Delegate;
import org.exolab.jms.net.uri.InvalidURIException;
import org.exolab.jms.net.uri.URIHelper;
/**
* <code>UnicastDelegate</code> supports the invocation of methods on a single
* remote object, over arbitrary transport protocols.
*
* @author <a href="mailto:tma@netspace.net.au">Tim Anderson</a>
* @version $Revision: 1.2 $ $Date: 2005/11/16 12:32:49 $
*/
public class UnicastDelegate implements Delegate, Serializable {
/**
* Serialization version.
*/
static final long serialVersionUID = 1;
/**
* The target object identifier.
*/
private ObjID _objID;
/**
* The connection URI.
*/
private String _uri;
/**
* The connection used to make invocations.
*/
private transient Connection _connection;
/**
* The connection factory.
*/
private transient ConnectionFactory _factory;
/**
* The logger.
*/
private static final Log _log = LogFactory.getLog(UnicastDelegate.class);
/**
* Default constructor for serialization support.
*/
protected UnicastDelegate() {
}
/**
* Construct a new <code>UnicastDelegate</code>.
* <p/>
* This is intended for use on the server side, to create delegates
* for serialization to clients.
*
* @param objID the identifier of the target object
* @param uri the connection URI
*/
public UnicastDelegate(ObjID objID, String uri) {
_objID = objID;
_uri = uri;
}
/**
* Construct a new <code>UnicastDelegate</code>.
* <p/>
* This is intended for use on the client side.
*
* @param objID the identifier of the target object
* @param connection the connection used to make invocations
*/
public UnicastDelegate(ObjID objID, Connection connection) {
_objID = objID;
_connection = connection;
}
/**
* Invoke a method.
*
* @param method the method to invoke
* @param args the arguments to pass
* @param methodID the unique identifier for the method
* @return the result of the invocation
* @throws Throwable for any error
*/
public Object invoke(Method method, Object[] args, long methodID)
throws Throwable {
Request request = new Request(_objID, method, args, methodID);
Response response = getConnection().invoke(request);
if (response.isException()) {
throw response.getException();
}
return response.getObject();
}
/**
* Dispose the delegate, releasing any resources.
* <p/>
* It is an error to invoke any method other than this, after the delegate
* has been disposed.
*/
public synchronized void dispose() {
if (_connection != null) {
try {
_connection.close();
} catch (ResourceException exception) {
_log.warn("Failed to close connection", exception);
} finally {
_connection = null;
_factory = null;
}
}
}
/**
* Returns the connection to perform invocations.
*
* @return the connection to perform invocations
* @throws InvalidURIException if the URI is invalid
* @throws ResourceException if a connection cannot be created
*/
protected synchronized Connection getConnection()
throws InvalidURIException, ResourceException {
if (_connection == null) {
_connection = _factory.getConnection(null, URIHelper.parse(_uri));
}
return _connection;
}
/**
* Write this to a stream.
*
* @param out the stream to write to
* @throws IOException for any I/O error
*/
private void writeObject(ObjectOutputStream out) throws IOException {
out.defaultWriteObject();
}
/**
* Read the state of this from a stream.
*
* @param in the stream to read from
* @throws ClassNotFoundException if a class cannot be deserialized
* @throws IOException for any I/O error
*/
private void readObject(ObjectInputStream in)
throws ClassNotFoundException, IOException {
in.defaultReadObject();
// try and get a reference to the connection
_connection = ConnectionContext.getConnection(URIHelper.parse(_uri));
if (_connection == null) {
// cache the factory, so the connection can be obtained when
// needed
_factory = ConnectionContext.getConnectionFactory();
}
}
}