ActiveMQ example source code file (UdpTransportServer.java)

This example ActiveMQ source code file (UdpTransportServer.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - ActiveMQ tags/keywords

caught, command, command, exception, io, ioexception, ioexception, net, network, received, reliabletransport, replaystrategy, transport, transport, udptransport, udptransport, udptransportserver, util

The ActiveMQ UdpTransportServer.java source code

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.activemq.transport.udp;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.SocketAddress;
import java.net.URI;
import java.util.HashMap;
import java.util.Map;

import org.apache.activemq.command.BrokerInfo;
import org.apache.activemq.command.Command;
import org.apache.activemq.openwire.OpenWireFormat;
import org.apache.activemq.transport.CommandJoiner;
import org.apache.activemq.transport.InactivityMonitor;
import org.apache.activemq.transport.Transport;
import org.apache.activemq.transport.TransportListener;
import org.apache.activemq.transport.TransportServer;
import org.apache.activemq.transport.TransportServerSupport;
import org.apache.activemq.transport.reliable.ReliableTransport;
import org.apache.activemq.transport.reliable.ReplayStrategy;
import org.apache.activemq.transport.reliable.Replayer;
import org.apache.activemq.util.ServiceStopper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * A UDP based implementation of {@link TransportServer}
 * 
 * 
 */

public class UdpTransportServer extends TransportServerSupport {
    private static final Logger LOG = LoggerFactory.getLogger(UdpTransportServer.class);

    private UdpTransport serverTransport;
    private ReplayStrategy replayStrategy;
    private Transport configuredTransport;
    private boolean usingWireFormatNegotiation;
    private Map<DatagramEndpoint, Transport> transports = new HashMap();

    public UdpTransportServer(URI connectURI, UdpTransport serverTransport, Transport configuredTransport, ReplayStrategy replayStrategy) {
        super(connectURI);
        this.serverTransport = serverTransport;
        this.configuredTransport = configuredTransport;
        this.replayStrategy = replayStrategy;
    }

    public String toString() {
        return "UdpTransportServer@" + serverTransport;
    }

    public void run() {
    }

    public UdpTransport getServerTransport() {
        return serverTransport;
    }

    public void setBrokerInfo(BrokerInfo brokerInfo) {
    }

    protected void doStart() throws Exception {
        LOG.info("Starting " + this);

        configuredTransport.setTransportListener(new TransportListener() {
            public void onCommand(Object o) {
                final Command command = (Command)o;
                processInboundConnection(command);
            }

            public void onException(IOException error) {
                LOG.error("Caught: " + error, error);
            }

            public void transportInterupted() {
            }

            public void transportResumed() {
            }
        });
        configuredTransport.start();
    }

    protected void doStop(ServiceStopper stopper) throws Exception {
        configuredTransport.stop();
    }

    protected void processInboundConnection(Command command) {
        DatagramEndpoint endpoint = (DatagramEndpoint)command.getFrom();
        if (LOG.isDebugEnabled()) {
            LOG.debug("Received command on: " + this + " from address: " + endpoint + " command: " + command);
        }
        Transport transport = null;
        synchronized (transports) {
            transport = transports.get(endpoint);
            if (transport == null) {
                if (usingWireFormatNegotiation && !command.isWireFormatInfo()) {
                    LOG.error("Received inbound server communication from: " + command.getFrom() + " expecting WireFormatInfo but was command: " + command);
                } else {
                    if (LOG.isDebugEnabled()) {
                        LOG.debug("Creating a new UDP server connection");
                    }
                    try {
                        transport = createTransport(command, endpoint);
                        transport = configureTransport(transport);
                        transports.put(endpoint, transport);
                    } catch (IOException e) {
                        LOG.error("Caught: " + e, e);
                        getAcceptListener().onAcceptError(e);
                    }
                }
            } else {
                LOG.warn("Discarding duplicate command to server from: " + endpoint + " command: " + command);
            }
        }
    }

    protected Transport configureTransport(Transport transport) {
        transport = new InactivityMonitor(transport, serverTransport.getWireFormat());
        getAcceptListener().onAccept(transport);
        return transport;
    }

    protected Transport createTransport(final Command command, DatagramEndpoint endpoint) throws IOException {
        if (endpoint == null) {
            throw new IOException("No endpoint available for command: " + command);
        }
        final SocketAddress address = endpoint.getAddress();
        final OpenWireFormat connectionWireFormat = serverTransport.getWireFormat().copy();
        final UdpTransport transport = new UdpTransport(connectionWireFormat, address);

        final ReliableTransport reliableTransport = new ReliableTransport(transport, transport);
        reliableTransport.getReplayer();
        reliableTransport.setReplayStrategy(replayStrategy);

        // Joiner must be on outside as the inbound messages must be processed
        // by the reliable transport first
        return new CommandJoiner(reliableTransport, connectionWireFormat) {
            public void start() throws Exception {
                super.start();
                reliableTransport.onCommand(command);
            }
        };

        /**
         * final WireFormatNegotiator wireFormatNegotiator = new
         * WireFormatNegotiator(configuredTransport, transport.getWireFormat(),
         * serverTransport .getMinmumWireFormatVersion()) { public void start()
         * throws Exception { super.start(); log.debug("Starting a new server
         * transport: " + this + " with command: " + command);
         * onCommand(command); } // lets use the specific addressing of wire
         * format protected void sendWireFormat(WireFormatInfo info) throws
         * IOException { log.debug("#### we have negotiated the wireformat;
         * sending a wireformat to: " + address); transport.oneway(info,
         * address); } }; return wireFormatNegotiator;
         */
    }

    public InetSocketAddress getSocketAddress() {
        return serverTransport.getLocalSocketAddress();
    }
}