/**
* 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 2003-2004 (C) Exoffice Technologies Inc. All Rights Reserved.
*
* $Id: Channel.java,v 1.4 2006/12/16 12:37:17 tanderson Exp $
*/
package org.exolab.jms.net.multiplexer;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.exolab.jms.net.connector.Request;
import org.exolab.jms.net.connector.Response;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.rmi.MarshalException;
import java.rmi.RemoteException;
import java.rmi.UnmarshalException;
/**
* A <code>Channel</code> represents a single-threaded virtual connection over a
* physical connection.
*
* @author <a href="mailto:tma@netspace.net.au">Tim Anderson</a>
* @version $Revision: 1.4 $ $Date: 2006/12/16 12:37:17 $
*/
class Channel implements Constants {
/**
* The channel identifier
*/
private int _id;
/**
* The multiplexer
*/
private Multiplexer _multiplexer;
/**
* The input stream
*/
private MultiplexInputStream _in;
/**
* The output stream
*/
private MultiplexOutputStream _out;
/**
* The logger
*/
private static final Log _log = LogFactory.getLog(Channel.class);
/**
* Construct a new <code>Channel</code>
*
* @param id the identifier for this channel
* @param multiplexer the multiplexer
* @param in the stream to receive data on
* @param out the stream to send data on
*/
public Channel(int id, Multiplexer multiplexer,
MultiplexInputStream in, MultiplexOutputStream out) {
_id = id;
_multiplexer = multiplexer;
_in = in;
_out = out;
}
/**
* Returns the channel identifier
*
* @return the channel identifier
*/
public int getId() {
return _id;
}
/**
* Invoke a method on a remote object.
*
* @param request the request
* @return the result of the invocation
* @throws RemoteException if the distributed call cannot be made
*/
public Response invoke(Request request) throws RemoteException {
if (_log.isDebugEnabled()) {
_log.debug("invoke() [channel=" + _id + "]");
}
Response response;
ObjectOutputStream out = null;
try {
// set the packet type
_out.setType(REQUEST);
// write the request
out = new ObjectOutputStream(_out);
request.write(out);
} catch (IOException exception) {
throw new MarshalException("Failed to marshal call", exception);
} catch (Exception exception) {
throw new MarshalException("Failed to marshal call", exception);
} finally {
if (out != null) {
try {
out.close();
} catch (IOException ignore) {
// no-op
}
}
}
// read the response
ObjectInputStream in = null;
try {
in = new ObjectInputStream(_in);
response = Response.read(in, request.getMethod());
} catch (ClassNotFoundException exception) {
throw new UnmarshalException("Failed to unmarshal response",
exception);
} catch (IOException exception) {
throw new UnmarshalException("Failed to unmarshal response",
exception);
} finally {
try {
if (in != null) {
in.close();
}
} catch (IOException ignore) {
// no-ops
}
}
if (_log.isDebugEnabled()) {
_log.debug("invoke() [channel=" + _id + "] - end");
}
return response;
}
/**
* Read a request from the channel.
* todo synchronization required due to scheduling in Multiplexer?
*
* @return the request
* @throws IOException if the request can't be read
*/
public synchronized Request readRequest() throws IOException {
Request request;
ObjectInputStream in = new ObjectInputStream(_in);
request = Request.read(in);
return request;
}
/**
* Write a response to a request.
* todo synchronization required due to scheduling in Multiplexer?
*
* @param response the response to write
* @throws IOException for any I/O error
*/
public synchronized void writeResponse(Response response)
throws IOException {
// set the packet type
_out.setType(RESPONSE);
// write the response
ObjectOutputStream out = new ObjectOutputStream(_out);
try {
response.write(out);
} finally {
out.close();
}
}
/**
* Invoked when the underlying physical connection is closed.
*/
public void disconnected() {
if (_log.isDebugEnabled()) {
_log.debug("disconnected [channel=" + _id + "]");
}
_in.disconnected();
_out.disconnected();
}
/**
* Returns the underlying input stream.
*
* @return the underlying input stream
*/
public MultiplexInputStream getMultiplexInputStream() {
return _in;
}
/**
* Returns the underlying output stream.
*
* @return the underlying output stream
*/
public MultiplexOutputStream getMultiplexOutputStream() {
return _out;
}
/**
* Releases this channel for re-use.
*/
public void release() {
_multiplexer.release(this);
}
/**
* Closes this channel.
*
* @throws IOException for any I/O error
*/
public void close() throws IOException {
if (_multiplexer != null) {
try {
_multiplexer.close(this);
} finally {
_multiplexer = null;
try {
_in.destroy();
} catch (IOException ignore) {
// no need to propagate
}
try {
_out.close();
} catch (IOException ignore) {
// no need to propagate
}
}
}
}
/**
* Destroy this channel.
*/
public void destroy() {
try {
close();
} catch (IOException exception) {
_log.debug("close() failed", exception);
}
}
/**
* Returns a string representation of this.
*
* @return a string representation of this
*/
public String toString() {
return "Channel[id=" + _id + ", out=" + _out + ", in=" + _in + " ]";
}
}