apps/MQTTSN-UDP-Client/src/org/eclipse/paho/mqttsn/udpclient/messages/mqttsn/MqttsPublish.java

/*******************************************************************************
 * Copyright (c) 2010, 2013 IBM Corp.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * and Eclipse Distribution License v1.0 which accompany this distribution. 
 *
 * The Eclipse Public License is available at 
 *    http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at 
 *   http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *    Ian Craggs - initial API and implementation and/or initial documentation
 *******************************************************************************/

package org.eclipse.paho.mqttsn.udpclient.messages.mqttsn;

import java.io.UnsupportedEncodingException;

import org.eclipse.paho.mqttsn.udpclient.utils.Utils;

/**
 * This object represents a Mqtts PUBLISH message.
 * 
 *
 */
public class MqttsPublish extends MqttsMessage {
		
	//Mqtts PUBLISH fields
	private boolean  dup;
	private int      qos;
	private	boolean retain;
	private int topicIdType;
	
	private byte[] byteTopicId;
	private int msgId;
	private byte[] pubData = null;
	
	//The form of TopicId (or short topic name) that depends on topicIdType.
	//Maybe either an int or a String.
	private int topicId = 0;
	private String shortTopicName = "";
	
	
	/**
	 * MqttsPublish constructor.Sets the appropriate message type. 
	 */
	public MqttsPublish() {
		msgType = MqttsMessage.PUBLISH;
	}
	
	/**
	 * MqttsPublish constructor.Sets the appropriate message type and constructs 
	 * a Mqtts PUBLISH message from a received byte array.
	 * @param data: The buffer that contains the PUBLISH message.
	 */
	public MqttsPublish(byte[] data) {
		msgType = MqttsMessage.PUBLISH;
		dup = ((data[2] & 0x80) >> 7 != 0);
		qos = (data[2] & 0x60) >> 5;
		if(qos == 3) qos = -1;
		retain = ((data[2] & 0x10) >> 4 != 0);
		topicIdType = (data[2] & 0x03);		
		
		byteTopicId = new byte[2];
		byteTopicId[0] = data[3];
		byteTopicId[1] = data[4];
		
		try {
			if (topicIdType == MqttsMessage.SHORT_TOPIC_NAME)
				shortTopicName = new String(byteTopicId,Utils.STRING_ENCODING);
			else if(topicIdType == MqttsMessage.NORMAL_TOPIC_ID || topicIdType == MqttsMessage.PREDIFINED_TOPIC_ID){
				topicId = ((byteTopicId[0] & 0xFF) << 8) + (byteTopicId[1] & 0xFF);
			}
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		}

		msgId   = ((data[5] & 0xFF) << 8) + (data[6] & 0xFF);
		int plength = (data[0] & 0xFF) - 7;
		pubData = new byte[plength];
		System.arraycopy(data, 7, pubData, 0, plength);				
	}
	
	/**
	 * Method to convert this message to a byte array for transmission.
	 * @return A byte array containing the PUBLISH message as it should appear on the wire.
	 */
	public byte[] toBytes() {
		int flags = 0;
		if(dup) {
			flags |= 0x80;
		}		
		if(qos == -1) {
			flags |= 0x60;
		} else if(qos == 0) {
		
		} else if(qos == 1) {
			flags |= 0x20;
		} else if(qos == 2) {
			flags |= 0x40;
		} else {
			throw new IllegalArgumentException("Unknown QoS value: " + qos);
		}
		if(retain) {
			flags |= 0x10;
		}
		if(topicIdType == MqttsMessage.NORMAL_TOPIC_ID){
			//do nothing
		}else if (topicIdType == MqttsMessage.PREDIFINED_TOPIC_ID){
			flags |= 0x01;
		}else if (topicIdType == MqttsMessage.SHORT_TOPIC_NAME){
			flags |= 0x02;
		}else {
			throw new IllegalArgumentException("Unknown topic id type: " + topicIdType);
		}
				
		int length = 7 + pubData.length;
		byte[] data = new byte[length];
		data[0] = (byte)length;   
		data[1] = (byte)msgType;
		data[2] = (byte)flags; 
		
		byteTopicId = new byte[2];
		if (topicIdType == MqttsMessage.SHORT_TOPIC_NAME)
			byteTopicId = shortTopicName.getBytes();
		else if(topicIdType == MqttsMessage.NORMAL_TOPIC_ID){
			byteTopicId[0] = (byte)((topicId >> 8) & 0xFF);
			byteTopicId[1] = (byte) (topicId & 0xFF);
		}else 
				throw new IllegalArgumentException("Unknown topic id type: " + topicIdType);
		System.arraycopy(byteTopicId, 0, data, 3, byteTopicId.length);	
		data[5] = (byte)((msgId >> 8) & 0xFF);
		data[6] = (byte) (msgId & 0xFF);
		System.arraycopy(pubData, 0, data, 7, pubData.length);
		return data;
	}

	public boolean isDup() {
		return dup;
	}

	public void setDup(boolean dup) {
		this.dup = dup;
	}

	public int getQos() {
		return qos;
	}

	public void setQos(int qos) {
		this.qos = qos;
	}

	public boolean isRetain() {
		return retain;
	}

	public void setRetain(boolean retain) {
		this.retain = retain;
	}

	public int getTopicIdType() {
		return topicIdType;
	}

	public void setTopicIdType(int topicIdType) {
		this.topicIdType = topicIdType;
	}

	public byte[] getData() {
		return pubData;
	}

	public void setData(byte[] data) {
		this.pubData = data;
	}

	public byte[] getByteTopicId() {
		return byteTopicId;
	}

	public void setByteTopicId(byte[] byteTopicId) {
		this.byteTopicId = byteTopicId;
	}
	
	public int getMsgId() {
		return msgId;
	}

	public void setMsgId(int msgId) {
		this.msgId = msgId;
	}

	public int getTopicId() {
		return topicId;
	}

	public void setTopicId(int topicId) {
		this.topicId = topicId;
	}

	public String getShortTopicName() {
		return shortTopicName;
	}

	public void setShortTopicName(String shortTopicName) {
		this.shortTopicName = shortTopicName;
	}
}