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.stomp;
018    
019    import java.io.ByteArrayInputStream;
020    import java.io.DataOutputStream;
021    import java.io.EOFException;
022    import java.io.IOException;
023    import java.net.Socket;
024    import java.net.URI;
025    import java.net.UnknownHostException;
026    import java.nio.ByteBuffer;
027    import java.nio.channels.SelectionKey;
028    import java.nio.channels.SocketChannel;
029    
030    import javax.net.SocketFactory;
031    
032    import org.apache.activemq.transport.Transport;
033    import org.apache.activemq.transport.nio.NIOOutputStream;
034    import org.apache.activemq.transport.nio.SelectorManager;
035    import org.apache.activemq.transport.nio.SelectorSelection;
036    import org.apache.activemq.transport.tcp.TcpTransport;
037    import org.apache.activemq.util.IOExceptionSupport;
038    import org.apache.activemq.util.ServiceStopper;
039    import org.apache.activemq.wireformat.WireFormat;
040    
041    /**
042     * An implementation of the {@link Transport} interface for using Stomp over NIO
043     *
044     *
045     */
046    public class StompNIOTransport extends TcpTransport {
047    
048        private SocketChannel channel;
049        private SelectorSelection selection;
050    
051        private ByteBuffer inputBuffer;
052        StompCodec codec;
053    
054        public StompNIOTransport(WireFormat wireFormat, SocketFactory socketFactory, URI remoteLocation, URI localLocation) throws UnknownHostException, IOException {
055            super(wireFormat, socketFactory, remoteLocation, localLocation);
056        }
057    
058        public StompNIOTransport(WireFormat wireFormat, Socket socket) throws IOException {
059            super(wireFormat, socket);
060        }
061    
062        protected void initializeStreams() throws IOException {
063            channel = socket.getChannel();
064            channel.configureBlocking(false);
065    
066            // listen for events telling us when the socket is readable.
067            selection = SelectorManager.getInstance().register(channel, new SelectorManager.Listener() {
068                public void onSelect(SelectorSelection selection) {
069                    serviceRead();
070                }
071    
072                public void onError(SelectorSelection selection, Throwable error) {
073                    if (error instanceof IOException) {
074                        onException((IOException)error);
075                    } else {
076                        onException(IOExceptionSupport.create(error));
077                    }
078                }
079            });
080    
081            inputBuffer = ByteBuffer.allocate(8 * 1024);
082            NIOOutputStream outPutStream = new NIOOutputStream(channel, 8 * 1024);
083            this.dataOut = new DataOutputStream(outPutStream);
084            this.buffOut = outPutStream;
085            codec = new StompCodec(this);
086        }
087    
088        private void serviceRead() {
089            try {
090    
091               while (true) {
092                   // read channel
093                   int readSize = channel.read(inputBuffer);
094                   // channel is closed, cleanup
095                   if (readSize == -1) {
096                       onException(new EOFException());
097                       selection.close();
098                       break;
099                   }
100    
101                   // nothing more to read, break
102                   if (readSize == 0) {
103                       break;
104                   }
105    
106                   receiveCounter += readSize;
107    
108                   inputBuffer.flip();
109    
110                   ByteArrayInputStream input = new ByteArrayInputStream(inputBuffer.array());
111                   codec.parse(input, readSize);
112    
113                   // clear the buffer
114                   inputBuffer.clear();
115               }
116            } catch (IOException e) {
117                onException(e);
118            } catch (Throwable e) {
119                onException(IOExceptionSupport.create(e));
120            }
121        }
122    
123        protected void doStart() throws Exception {
124            connect();
125            selection.setInterestOps(SelectionKey.OP_READ);
126            selection.enable();
127        }
128    
129        protected void doStop(ServiceStopper stopper) throws Exception {
130            try {
131                if (selection != null) {
132                    selection.close();
133                }
134            } finally {
135                super.doStop(stopper);
136            }
137        }
138    }