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 */ 017package org.apache.activemq.transport.mqtt; 018 019import java.io.DataOutputStream; 020import java.io.EOFException; 021import java.io.IOException; 022import java.net.Socket; 023import java.net.URI; 024import java.net.UnknownHostException; 025import java.nio.ByteBuffer; 026import java.nio.channels.SelectionKey; 027import java.nio.channels.SocketChannel; 028 029import javax.net.SocketFactory; 030import org.apache.activemq.transport.nio.NIOOutputStream; 031import org.apache.activemq.transport.nio.SelectorManager; 032import org.apache.activemq.transport.nio.SelectorSelection; 033import org.apache.activemq.transport.tcp.TcpTransport; 034import org.apache.activemq.util.IOExceptionSupport; 035import org.apache.activemq.util.ServiceStopper; 036import org.apache.activemq.wireformat.WireFormat; 037import org.fusesource.hawtbuf.DataByteArrayInputStream; 038 039/** 040 * An implementation of the {@link org.apache.activemq.transport.Transport} interface for using MQTT over NIO 041 */ 042public class MQTTNIOTransport extends TcpTransport { 043 044 private SocketChannel channel; 045 private SelectorSelection selection; 046 047 private ByteBuffer inputBuffer; 048 MQTTCodec codec; 049 050 public MQTTNIOTransport(WireFormat wireFormat, SocketFactory socketFactory, URI remoteLocation, URI localLocation) throws UnknownHostException, IOException { 051 super(wireFormat, socketFactory, remoteLocation, localLocation); 052 } 053 054 public MQTTNIOTransport(WireFormat wireFormat, Socket socket) throws IOException { 055 super(wireFormat, socket); 056 } 057 058 protected void initializeStreams() throws IOException { 059 channel = socket.getChannel(); 060 channel.configureBlocking(false); 061 // listen for events telling us when the socket is readable. 062 selection = SelectorManager.getInstance().register(channel, new SelectorManager.Listener() { 063 public void onSelect(SelectorSelection selection) { 064 if (!isStopped()) { 065 serviceRead(); 066 } 067 } 068 069 public void onError(SelectorSelection selection, Throwable error) { 070 if (error instanceof IOException) { 071 onException((IOException) error); 072 } else { 073 onException(IOExceptionSupport.create(error)); 074 } 075 } 076 }); 077 078 inputBuffer = ByteBuffer.allocate(8 * 1024); 079 NIOOutputStream outPutStream = new NIOOutputStream(channel, 8 * 1024); 080 this.dataOut = new DataOutputStream(outPutStream); 081 this.buffOut = outPutStream; 082 codec = new MQTTCodec(this); 083 } 084 085 private void serviceRead() { 086 try { 087 088 while (isStarted()) { 089 // read channel 090 int readSize = channel.read(inputBuffer); 091 // channel is closed, cleanup 092 if (readSize == -1) { 093 onException(new EOFException()); 094 selection.close(); 095 break; 096 } 097 // nothing more to read, break 098 if (readSize == 0) { 099 break; 100 } 101 102 inputBuffer.flip(); 103 DataByteArrayInputStream dis = new DataByteArrayInputStream(inputBuffer.array()); 104 codec.parse(dis, readSize); 105 106 // clear the buffer 107 inputBuffer.clear(); 108 109 } 110 } catch (IOException e) { 111 onException(e); 112 } catch (Throwable e) { 113 onException(IOExceptionSupport.create(e)); 114 } 115 } 116 117 protected void doStart() throws Exception { 118 connect(); 119 selection.setInterestOps(SelectionKey.OP_READ); 120 selection.enable(); 121 } 122 123 protected void doStop(ServiceStopper stopper) throws Exception { 124 try { 125 if (selection != null) { 126 selection.close(); 127 } 128 } finally { 129 super.doStop(stopper); 130 } 131 } 132}