org.jboss.ejb.client.remoting.SessionOpenResponseHandler Maven / Gradle / Ivy

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/*
 * JBoss, Home of Professional Open Source.
 * Copyright 2011, Red Hat, Inc., and individual contributors
 * as indicated by the @author tags. See the copyright.txt file in the
 * distribution for a full listing of individual contributors.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */

package org.jboss.ejb.client.remoting;

import org.jboss.ejb.client.Affinity;
import org.jboss.ejb.client.EJBReceiverInvocationContext;
import org.jboss.ejb.client.Logs;
import org.jboss.ejb.client.SessionID;
import org.jboss.marshalling.MarshallerFactory;
import org.jboss.marshalling.Unmarshaller;

import java.io.DataInputStream;
import java.io.IOException;
import java.io.InputStream;

/**
 * Responsible for parsing a stream for a (prior) session open request's response, as per the EJB remote client protocol
 * 
 * User: Jaikiran Pai
 */
class SessionOpenResponseHandler extends ProtocolMessageHandler {

    private final ChannelAssociation channelAssociation;
    private final MarshallerFactory marshallerFactory;

    SessionOpenResponseHandler(final ChannelAssociation channelAssociation, final MarshallerFactory marshallerFactory) {
        this.channelAssociation = channelAssociation;
        this.marshallerFactory = marshallerFactory;
    }

    /**
     * Processes the passed MessageInputStream for a session id response, for a (prior) session open request
     * This method does not fully read the passed stream, instead it reads enough to create a {@link org.jboss.ejb.client.EJBReceiverInvocationContext.ResultProducer}
     * which can then read the rest of the stream when the {@link org.jboss.ejb.client.EJBReceiverInvocationContext.ResultProducer#getResult()} is called
     *
     *
     * @param inputStream@throws IOException If there's a problem reading the stream
     */
    @Override
    protected void processMessage(final InputStream inputStream) throws IOException {
        if (inputStream == null) {
            throw Logs.MAIN.paramCannotBeNull("Message input stream");
        }
        final DataInputStream input = new DataInputStream(inputStream);
        // read the invocation id
        final short invocationId = input.readShort();
        // create a ResultProducer which can be used to get the session id result
        final EJBReceiverInvocationContext.ResultProducer resultProducer = new SessionIDResultProducer(input);
        this.channelAssociation.resultReady(invocationId, resultProducer);
    }

    /**
     * A result producer which reads a input stream to return a session id as a result
     */
    private class SessionIDResultProducer implements EJBReceiverInvocationContext.ResultProducer {

        private final DataInputStream input;

        SessionIDResultProducer(final DataInputStream input) {
            this.input = input;
        }

        @Override
        public Object getResult() throws Exception {
            try {
                // read the session id length
                final int sessionIdLength = PackedInteger.readPackedInteger(input);
                final byte[] sessionIdBytes = new byte[sessionIdLength];
                // read the session id
                this.input.read(sessionIdBytes);
                final SessionID sessionID = SessionID.createSessionID(sessionIdBytes);
                // now read/unmarshal the affinity associated with this session
                final Unmarshaller unmarshaller = SessionOpenResponseHandler.this.prepareForUnMarshalling(SessionOpenResponseHandler.this.marshallerFactory, input);
                final Affinity affinity = (Affinity) unmarshaller.readObject();

                // finish unmarshalling
                unmarshaller.finish();
                // return the result
                return new SessionOpenResponse(sessionID, affinity);

            } finally {
                this.input.close();
            }
        }

        @Override
        public void discardResult() {
        }
    }

    /**
     * A session open response which holds the session id that was generated for a session open request and
     * also the affinity associated with that session
     */
    final class SessionOpenResponse {
        private final SessionID sessionID;
        private final Affinity affinity;

        SessionOpenResponse(final SessionID sessionID, final Affinity affinity) {
            this.sessionID = sessionID;
            this.affinity = affinity;
        }

        SessionID getSessionID() {
            return this.sessionID;
        }

        Affinity getAffinity() {
            return this.affinity;
        }
    }
}