001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.activemq.transport.udp;
018    
019    import java.io.IOException;
020    import java.net.URI;
021    import java.net.URISyntaxException;
022    import java.net.UnknownHostException;
023    import java.util.HashMap;
024    import java.util.Map;
025    
026    import org.apache.activemq.openwire.OpenWireFormat;
027    import org.apache.activemq.transport.CommandJoiner;
028    import org.apache.activemq.transport.InactivityMonitor;
029    import org.apache.activemq.transport.Transport;
030    import org.apache.activemq.transport.TransportFactory;
031    import org.apache.activemq.transport.TransportLoggerFactory;
032    import org.apache.activemq.transport.TransportServer;
033    import org.apache.activemq.transport.reliable.DefaultReplayStrategy;
034    import org.apache.activemq.transport.reliable.ExceptionIfDroppedReplayStrategy;
035    import org.apache.activemq.transport.reliable.ReliableTransport;
036    import org.apache.activemq.transport.reliable.ReplayStrategy;
037    import org.apache.activemq.transport.reliable.Replayer;
038    import org.apache.activemq.transport.tcp.TcpTransportFactory;
039    import org.apache.activemq.util.IOExceptionSupport;
040    import org.apache.activemq.util.IntSequenceGenerator;
041    import org.apache.activemq.util.IntrospectionSupport;
042    import org.apache.activemq.util.URISupport;
043    import org.apache.activemq.wireformat.WireFormat;
044    import org.slf4j.Logger;
045    import org.slf4j.LoggerFactory;
046    
047    /**
048     * @author David Martin Clavo david(dot)martin(dot)clavo(at)gmail.com (logging improvement modifications)
049     * 
050     */
051    public class UdpTransportFactory extends TransportFactory {
052        
053        private static final Logger log = LoggerFactory.getLogger(TcpTransportFactory.class);
054        
055        public TransportServer doBind(final URI location) throws IOException {
056            try {
057                Map<String, String> options = new HashMap<String, String>(URISupport.parseParameters(location));
058                if (options.containsKey("port")) {
059                    throw new IllegalArgumentException("The port property cannot be specified on a UDP server transport - please use the port in the URI syntax");
060                }
061                WireFormat wf = createWireFormat(options);
062                int port = location.getPort();
063                OpenWireFormat openWireFormat = asOpenWireFormat(wf);
064                UdpTransport transport = (UdpTransport) createTransport(location.getPort(), wf);
065    
066                Transport configuredTransport = configure(transport, wf, options, true);
067                UdpTransportServer server = new UdpTransportServer(location, transport, configuredTransport, createReplayStrategy());
068                return server;
069            } catch (URISyntaxException e) {
070                throw IOExceptionSupport.create(e);
071            } catch (Exception e) {
072                throw IOExceptionSupport.create(e);
073            }
074        }
075    
076        public Transport configure(Transport transport, WireFormat format, Map options) throws Exception {
077            return configure(transport, format, options, false);
078        }
079    
080        public Transport compositeConfigure(Transport transport, WireFormat format, Map options) {
081            IntrospectionSupport.setProperties(transport, options);
082            final UdpTransport udpTransport = (UdpTransport)transport;
083    
084            // deal with fragmentation
085            transport = new CommandJoiner(transport, asOpenWireFormat(format));
086    
087            if (udpTransport.isTrace()) {
088                try {
089                    transport = TransportLoggerFactory.getInstance().createTransportLogger(transport);
090                } catch (Throwable e) {
091                    log.error("Could not create TransportLogger object for: " + TransportLoggerFactory.defaultLogWriterName + ", reason: " + e, e);
092                }
093            }
094    
095            transport = new InactivityMonitor(transport, format);
096    
097            if (format instanceof OpenWireFormat) {
098                transport = configureClientSideNegotiator(transport, format, udpTransport);
099            }
100    
101            return transport;
102        }
103    
104        protected Transport createTransport(URI location, WireFormat wf) throws UnknownHostException, IOException {
105            OpenWireFormat wireFormat = asOpenWireFormat(wf);
106            return new UdpTransport(wireFormat, location);
107        }
108    
109        protected Transport createTransport(int port, WireFormat wf) throws UnknownHostException, IOException {
110            OpenWireFormat wireFormat = asOpenWireFormat(wf);
111            return new UdpTransport(wireFormat, port);
112        }
113    
114        /**
115         * Configures the transport
116         * 
117         * @param acceptServer true if this transport is used purely as an 'accept'
118         *                transport for new connections which work like TCP
119         *                SocketServers where new connections spin up a new separate
120         *                UDP transport
121         */
122        protected Transport configure(Transport transport, WireFormat format, Map options, boolean acceptServer) throws Exception {
123            IntrospectionSupport.setProperties(transport, options);
124            UdpTransport udpTransport = (UdpTransport)transport;
125    
126            OpenWireFormat openWireFormat = asOpenWireFormat(format);
127    
128            if (udpTransport.isTrace()) {
129                transport = TransportLoggerFactory.getInstance().createTransportLogger(transport);
130            }
131    
132            transport = new InactivityMonitor(transport, format);
133    
134            if (!acceptServer && format instanceof OpenWireFormat) {
135                transport = configureClientSideNegotiator(transport, format, udpTransport);
136            }
137    
138            // deal with fragmentation
139    
140            if (acceptServer) {
141                // lets not support a buffer of messages to enable reliable
142                // messaging on the 'accept server' transport
143                udpTransport.setReplayEnabled(false);
144    
145                // we don't want to do reliable checks on this transport as we
146                // delegate to one that does
147                transport = new CommandJoiner(transport, openWireFormat);
148                return transport;
149            } else {
150                ReliableTransport reliableTransport = new ReliableTransport(transport, udpTransport);
151                Replayer replayer = reliableTransport.getReplayer();
152                reliableTransport.setReplayStrategy(createReplayStrategy(replayer));
153    
154                // Joiner must be on outside as the inbound messages must be
155                // processed by the reliable transport first
156                return new CommandJoiner(reliableTransport, openWireFormat);
157            }
158        }
159    
160        protected ReplayStrategy createReplayStrategy(Replayer replayer) {
161            if (replayer != null) {
162                return new DefaultReplayStrategy(5);
163            }
164            return new ExceptionIfDroppedReplayStrategy(1);
165        }
166    
167        protected ReplayStrategy createReplayStrategy() {
168            return new DefaultReplayStrategy(5);
169        }
170    
171        protected Transport configureClientSideNegotiator(Transport transport, WireFormat format, final UdpTransport udpTransport) {
172            return new ResponseRedirectInterceptor(transport, udpTransport);
173        }
174    
175        protected OpenWireFormat asOpenWireFormat(WireFormat wf) {
176            OpenWireFormat answer = (OpenWireFormat)wf;
177            return answer;
178        }
179    }