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.mqtt; 018 019 import java.io.DataInput; 020 import java.io.DataInputStream; 021 import java.io.DataOutput; 022 import java.io.DataOutputStream; 023 import java.io.IOException; 024 025 import org.apache.activemq.util.ByteArrayInputStream; 026 import org.apache.activemq.util.ByteArrayOutputStream; 027 import org.apache.activemq.util.ByteSequence; 028 import org.apache.activemq.wireformat.WireFormat; 029 import org.fusesource.hawtbuf.Buffer; 030 import org.fusesource.mqtt.codec.MQTTFrame; 031 032 /** 033 * Implements marshalling and unmarsalling the <a 034 * href="http://mqtt.org/">MQTT</a> protocol. 035 */ 036 public class MQTTWireFormat implements WireFormat { 037 038 039 static final int MAX_MESSAGE_LENGTH = 1024 * 1024 * 256; 040 041 private boolean encodingEnabled = false; 042 private int version = 1; 043 044 public ByteSequence marshal(Object command) throws IOException { 045 ByteArrayOutputStream baos = new ByteArrayOutputStream(); 046 DataOutputStream dos = new DataOutputStream(baos); 047 marshal(command, dos); 048 dos.close(); 049 return baos.toByteSequence(); 050 } 051 052 public Object unmarshal(ByteSequence packet) throws IOException { 053 ByteArrayInputStream stream = new ByteArrayInputStream(packet); 054 DataInputStream dis = new DataInputStream(stream); 055 return unmarshal(dis); 056 } 057 058 public void marshal(Object command, DataOutput dataOut) throws IOException { 059 MQTTFrame frame = (MQTTFrame) command; 060 dataOut.write(frame.header()); 061 062 int remaining = 0; 063 for (Buffer buffer : frame.buffers) { 064 remaining += buffer.length; 065 } 066 do { 067 byte digit = (byte) (remaining & 0x7F); 068 remaining >>>= 7; 069 if (remaining > 0) { 070 digit |= 0x80; 071 } 072 dataOut.write(digit); 073 } while (remaining > 0); 074 for (Buffer buffer : frame.buffers) { 075 dataOut.write(buffer.data, buffer.offset, buffer.length); 076 } 077 } 078 079 public Object unmarshal(DataInput dataIn) throws IOException { 080 byte header = dataIn.readByte(); 081 082 byte digit; 083 int multiplier = 1; 084 int length = 0; 085 do { 086 digit = dataIn.readByte(); 087 length += (digit & 0x7F) * multiplier; 088 multiplier <<= 7; 089 } 090 while ((digit & 0x80) != 0); 091 092 if (length >= 0) { 093 if (length > MAX_MESSAGE_LENGTH) { 094 throw new IOException("The maximum message length was exceeded"); 095 } 096 097 if (length > 0) { 098 byte[] data = new byte[length]; 099 dataIn.readFully(data); 100 Buffer body = new Buffer(data); 101 return new MQTTFrame(body).header(header); 102 } else { 103 return new MQTTFrame().header(header); 104 } 105 } 106 return null; 107 } 108 109 /** 110 * @param the version of the wire format 111 */ 112 public void setVersion(int version) { 113 this.version = version; 114 } 115 116 /** 117 * @return the version of the wire format 118 */ 119 public int getVersion() { 120 return this.version; 121 } 122 123 124 }