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/******************************************************************************* * Copyright (c) 2009, 2014 IBM Corp. * * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v2.0 * and Eclipse Distribution License v1.0 which accompany this distribution. * * The Eclipse Public License is available at * https://www.eclipse.org/legal/epl-2.0 * and the Eclipse Distribution License is available at * https://www.eclipse.org/org/documents/edl-v10.php * * Contributors: * Dave Locke - initial API and implementation and/or initial documentation */ package org.eclipse.paho.sample.mqttv3app; import java.io.IOException; import java.sql.Timestamp; import java.util.Arrays; import org.eclipse.paho.client.mqttv3.IMqttActionListener; import org.eclipse.paho.client.mqttv3.IMqttDeliveryToken; import org.eclipse.paho.client.mqttv3.IMqttToken; import org.eclipse.paho.client.mqttv3.MqttAsyncClient; import org.eclipse.paho.client.mqttv3.MqttCallback; import org.eclipse.paho.client.mqttv3.MqttConnectOptions; import org.eclipse.paho.client.mqttv3.MqttException; import org.eclipse.paho.client.mqttv3.MqttMessage; import org.eclipse.paho.client.mqttv3.persist.MqttDefaultFilePersistence; /** * A sample application that demonstrates how to use the Paho MQTT v3.1 Client API in * non-blocking callback/notification mode. * * It can be run from the command line in one of two modes: * - as a publisher, sending a single message to a topic on the server * - as a subscriber, listening for messages from the server * * There are three versions of the sample that implement the same features * but do so using using different programming styles: * <ol> * <li>Sample which uses the API which blocks until the operation completes</li> * <li>SampleAsyncWait shows how to use the asynchronous API with waiters that block until * an action completes</li> * <li>SampleAsyncCallBack (this one) shows how to use the asynchronous API where events are * used to notify the application when an action completes<li> * </ol> * * If the application is run with the -h parameter then info is displayed that * describes all of the options / parameters. */ public class SampleAsyncCallBack implements MqttCallback { int state = BEGIN; static final int BEGIN = 0; static final int CONNECTED = 1; static final int PUBLISHED = 2; static final int SUBSCRIBED = 3; static final int DISCONNECTED = 4; static final int FINISH = 5; static final int ERROR = 6; static final int DISCONNECT = 7; /** * The main entry point of the sample. * * This method handles parsing the arguments specified on the * command-line before performing the specified action. */ public static void main(String[] args) { // Default settings: boolean quietMode = false; String action = "publish"; String topic = ""; String message = "Message from async callback Paho MQTTv3 Java client sample"; int qos = 2; String broker = "m2m.eclipse.org"; int port = 1883; String clientId = null; String subTopic = "Sample/#"; String pubTopic = "Sample/Java/v3"; boolean cleanSession = true; // Non durable subscriptions boolean ssl = false; String password = null; String userName = null; // Parse the arguments - for (int i=0; i<args.length; i++) { // Check this is a valid argument if (args[i].length() == 2 && args[i].startsWith("-")) { char arg = args[i].charAt(1); // Handle arguments that take no-value switch(arg) { case 'h': case '?': printHelp(); return; case 'q': quietMode = true; continue; } // Now handle the arguments that take a value and // ensure one is specified if (i == args.length -1 || args[i+1].charAt(0) == '-') { System.out.println("Missing value for argument: "+args[i]); printHelp(); return; } switch(arg) { case 'a': action = args[++i]; break; case 't': topic = args[++i]; break; case 'm': message = args[++i]; break; case 's': qos = Integer.parseInt(args[++i]); break; case 'b': broker = args[++i]; break; case 'p': port = Integer.parseInt(args[++i]); break; case 'i': clientId = args[++i]; break; case 'c': cleanSession = Boolean.valueOf(args[++i]).booleanValue(); break; case 'k': System.getProperties().put("javax.net.ssl.keyStore", args[++i]); break; case 'w': System.getProperties().put("javax.net.ssl.keyStorePassword", args[++i]); break; case 'r': System.getProperties().put("javax.net.ssl.trustStore", args[++i]); break; case 'v': ssl = Boolean.valueOf(args[++i]).booleanValue(); break; case 'u': userName = args[++i]; break; case 'z': password = args[++i]; break; default: System.out.println("Unrecognised argument: "+args[i]); printHelp(); return; } } else { System.out.println("Unrecognised argument: "+args[i]); printHelp(); return; } } // Validate the provided arguments if (!action.equals("publish") && !action.equals("subscribe")) { System.out.println("Invalid action: "+action); printHelp(); return; } if (qos < 0 || qos > 2) { System.out.println("Invalid QoS: "+qos); printHelp(); return; } if (topic.equals("")) { // Set the default topic according to the specified action if (action.equals("publish")) { topic = pubTopic; } else { topic = subTopic; } } String protocol = "tcp://"; if (ssl) { protocol = "ssl://"; } String url = protocol + broker + ":" + port; if (clientId == null || clientId.equals("")) { clientId = "SampleJavaV3_"+action; } // With a valid set of arguments, the real work of // driving the client API can begin try { // Create an instance of the Sample client wrapper SampleAsyncCallBack sampleClient = new SampleAsyncCallBack(url,clientId,cleanSession, quietMode,userName,password); // Perform the specified action if (action.equals("publish")) { sampleClient.publish(topic,qos,message.getBytes()); } else if (action.equals("subscribe")) { sampleClient.subscribe(topic,qos); } } catch(MqttException me) { // Display full details of any exception that occurs System.out.println("reason "+me.getReasonCode()); System.out.println("msg "+me.getMessage()); System.out.println("loc "+me.getLocalizedMessage()); System.out.println("cause "+me.getCause()); System.out.println("excep "+me); me.printStackTrace(); } catch (Throwable th) { System.out.println("Throwable caught "+th); th.printStackTrace(); } } // Private instance variables MqttAsyncClient client; String brokerUrl; private boolean quietMode; private MqttConnectOptions conOpt; private boolean clean; Throwable ex = null; Object waiter = new Object(); boolean donext = false; private String password; private String userName; /** * Constructs an instance of the sample client wrapper * @param brokerUrl the url to connect to * @param clientId the client id to connect with * @param cleanSession clear state at end of connection or not (durable or non-durable subscriptions) * @param quietMode whether debug should be printed to standard out * @param userName the username to connect with * @param password the password for the user * @throws MqttException */ public SampleAsyncCallBack(String brokerUrl, String clientId, boolean cleanSession, boolean quietMode, String userName, String password) throws MqttException { this.brokerUrl = brokerUrl; this.quietMode = quietMode; this.clean = cleanSession; this.password = password; this.userName = userName; //This sample stores in a temporary directory... where messages temporarily // stored until the message has been delivered to the server. //..a real application ought to store them somewhere // where they are not likely to get deleted or tampered with String tmpDir = System.getProperty("java.io.tmpdir"); MqttDefaultFilePersistence dataStore = new MqttDefaultFilePersistence(tmpDir); try { // Construct the object that contains connection parameters // such as cleanSession and LWT conOpt = new MqttConnectOptions(); conOpt.setCleanSession(clean); if(password != null ) { conOpt.setPassword(this.password.toCharArray()); } if(userName != null) { conOpt.setUserName(this.userName); } // Construct the MqttClient instance client = new MqttAsyncClient(this.brokerUrl,clientId, dataStore); // Set this wrapper as the callback handler client.setCallback(this); } catch (MqttException e) { e.printStackTrace(); log("Unable to set up client: "+e.toString()); System.exit(1); } } /** * Publish / send a message to an MQTT server * @param topicName the name of the topic to publish to * @param qos the quality of service to delivery the message at (0,1,2) * @param payload the set of bytes to send to the MQTT server * @throws MqttException */ public void publish(String topicName, int qos, byte[] payload) throws Throwable { // Use a state machine to decide which step to do next. State change occurs // when a notification is received that an MQTT action has completed while (state != FINISH) { switch (state) { case BEGIN: // Connect using a non-blocking connect MqttConnector con = new MqttConnector(); con.doConnect(); break; case CONNECTED: // Publish using a non-blocking publisher Publisher pub = new Publisher(); pub.doPublish(topicName, qos, payload); break; case PUBLISHED: state = DISCONNECT; donext = true; break; case DISCONNECT: Disconnector disc = new Disconnector(); disc.doDisconnect(); break; case ERROR: throw ex; case DISCONNECTED: state = FINISH; donext = true; break; } // if (state != FINISH) { // Wait until notified about a state change and then perform next action waitForStateChange(10000); // } } } /** * Wait for a maximum amount of time for a state change event to occur * @param maxTTW maximum time to wait in milliseconds * @throws MqttException */ private void waitForStateChange(int maxTTW ) throws MqttException { synchronized (waiter) { if (!donext ) { try { waiter.wait(maxTTW); } catch (InterruptedException e) { log("timed out"); e.printStackTrace(); } if (ex != null) { throw (MqttException)ex; } } donext = false; } } /** * Subscribe to a topic on an MQTT server * Once subscribed this method waits for the messages to arrive from the server * that match the subscription. It continues listening for messages until the enter key is * pressed. * @param topicName to subscribe to (can be wild carded) * @param qos the maximum quality of service to receive messages at for this subscription * @throws MqttException */ public void subscribe(String topicName, int qos) throws Throwable { // Use a state machine to decide which step to do next. State change occurs // when a notification is received that an MQTT action has completed while (state != FINISH) { switch (state) { case BEGIN: // Connect using a non-blocking connect MqttConnector con = new MqttConnector(); con.doConnect(); break; case CONNECTED: // Subscribe using a non-blocking subscribe Subscriber sub = new Subscriber(); sub.doSubscribe(topicName, qos); break; case SUBSCRIBED: // Block until Enter is pressed allowing messages to arrive log("Press <Enter> to exit"); try { System.in.read(); } catch (IOException e) { //If we can't read we'll just exit } state = DISCONNECT; donext = true; break; case DISCONNECT: Disconnector disc = new Disconnector(); disc.doDisconnect(); break; case ERROR: throw ex; case DISCONNECTED: state = FINISH; donext = true; break; } // if (state != FINISH && state != DISCONNECT) { waitForStateChange(10000); } // } } /** * Utility method to handle logging. If 'quietMode' is set, this method does nothing * @param message the message to log */ void log(String message) { if (!quietMode) { System.out.println(message); } } /****************************************************************/ /* Methods to implement the MqttCallback interface */ /****************************************************************/ /** * @see MqttCallback#connectionLost(Throwable) */ public void connectionLost(Throwable cause) { // Called when the connection to the server has been lost. // An application may choose to implement reconnection // logic at this point. This sample simply exits. log("Connection to " + brokerUrl + " lost!" + cause); System.exit(1); } /** * @see MqttCallback#deliveryComplete(IMqttDeliveryToken) */ public void deliveryComplete(IMqttDeliveryToken token) { // Called when a message has been delivered to the // server. The token passed in here is the same one // that was returned from the original call to publish. // This allows applications to perform asynchronous // delivery without blocking until delivery completes. // // This sample demonstrates asynchronous deliver, registering // a callback to be notified on each call to publish. // // The deliveryComplete method will also be called if // the callback is set on the client // // note that token.getTopics() returns an array so we convert to a string // before printing it on the console log("Delivery complete callback: Publish Completed "+Arrays.toString(token.getTopics())); } /** * @see MqttCallback#messageArrived(String, MqttMessage) */ public void messageArrived(String topic, MqttMessage message) throws MqttException { // Called when a message arrives from the server that matches any // subscription made by the client String time = new Timestamp(System.currentTimeMillis()).toString(); System.out.println("Time:\t" +time + " Topic:\t" + topic + " Message:\t" + new String(message.getPayload()) + " QoS:\t" + message.getQos()); } /****************************************************************/ /* End of MqttCallback methods */ /****************************************************************/ static void printHelp() { System.out.println( "Syntax:\n\n" + " SampleAsyncCallBack [-h] [-a publish|subscribe] [-t <topic>] [-m <message text>]\n" + " [-s 0|1|2] -b <hostname|IP address>] [-p <brokerport>] [-i <clientID>]\n\n" + " -h Print this help text and quit\n" + " -q Quiet mode (default is false)\n" + " -a Perform the relevant action (default is publish)\n" + " -t Publish/subscribe to <topic> instead of the default\n" + " (publish: \"Sample/Java/v3\", subscribe: \"Sample/#\")\n" + " -m Use <message text> instead of the default\n" + " (\"Message from MQTTv3 Java client\")\n" + " -s Use this QoS instead of the default (2)\n" + " -b Use this name/IP address instead of the default (m2m.eclipse.org)\n" + " -p Use this port instead of the default (1883)\n\n" + " -i Use this client ID instead of SampleJavaV3_<action>\n" + " -c Connect to the server with a clean session (default is false)\n" + " \n\n Security Options \n" + " -u Username \n" + " -z Password \n" + " \n\n SSL Options \n" + " -v SSL enabled; true - (default is false) " + " -k Use this JKS format key store to verify the client\n" + " -w Passpharse to verify certificates in the keys store\n" + " -r Use this JKS format keystore to verify the server\n" + " If javax.net.ssl properties have been set only the -v flag needs to be set\n" + "Delimit strings containing spaces with \"\"\n\n" + "Publishers transmit a single message then disconnect from the server.\n" + "Subscribers remain connected to the server and receive appropriate\n" + "messages until <enter> is pressed.\n\n" ); } /** * Connect in a non-blocking way and then sit back and wait to be * notified that the action has completed. */ public class MqttConnector { public MqttConnector() { } public void doConnect() { // Connect to the server // Get a token and setup an asynchronous listener on the token which // will be notified once the connect completes log("Connecting to "+brokerUrl + " with client ID "+client.getClientId()); IMqttActionListener conListener = new IMqttActionListener() { public void onSuccess(IMqttToken asyncActionToken) { log("Connected"); state = CONNECTED; carryOn(); } public void onFailure(IMqttToken asyncActionToken, Throwable exception) { ex = exception; state = ERROR; log ("connect failed" +exception); carryOn(); } public void carryOn() { synchronized (waiter) { donext=true; waiter.notifyAll(); } } }; try { // Connect using a non-blocking connect client.connect(conOpt,"Connect sample context", conListener); } catch (MqttException e) { // If though it is a non-blocking connect an exception can be // thrown if validation of parms fails or other checks such // as already connected fail. state = ERROR; donext = true; ex = e; } } } /** * Publish in a non-blocking way and then sit back and wait to be * notified that the action has completed. */ public class Publisher { public void doPublish(String topicName, int qos, byte[] payload) { // Send / publish a message to the server // Get a token and setup an asynchronous listener on the token which // will be notified once the message has been delivered MqttMessage message = new MqttMessage(payload); message.setQos(qos); String time = new Timestamp(System.currentTimeMillis()).toString(); log("Publishing at: "+time+ " to topic \""+topicName+"\" qos "+qos); // Setup a listener object to be notified when the publish completes. // IMqttActionListener pubListener = new IMqttActionListener() { public void onSuccess(IMqttToken asyncActionToken) { log("Publish Completed"); state = PUBLISHED; carryOn(); } public void onFailure(IMqttToken asyncActionToken, Throwable exception) { ex = exception; state = ERROR; log ("Publish failed" +exception); carryOn(); } public void carryOn() { synchronized (waiter) { donext=true; waiter.notifyAll(); } } }; try { // Publish the message client.publish(topicName, message, "Pub sample context", pubListener); } catch (MqttException e) { state = ERROR; donext = true; ex = e; } } } /** * Subscribe in a non-blocking way and then sit back and wait to be * notified that the action has completed. */ public class Subscriber { public void doSubscribe(String topicName, int qos) { // Make a subscription // Get a token and setup an asynchronous listener on the token which // will be notified once the subscription is in place. log("Subscribing to topic \""+topicName+"\" qos "+qos); IMqttActionListener subListener = new IMqttActionListener() { public void onSuccess(IMqttToken asyncActionToken) { log("Subscribe Completed"); state = SUBSCRIBED; carryOn(); } public void onFailure(IMqttToken asyncActionToken, Throwable exception) { ex = exception; state = ERROR; log ("Subscribe failed" +exception); carryOn(); } public void carryOn() { synchronized (waiter) { donext=true; waiter.notifyAll(); } } }; try { client.subscribe(topicName, qos, "Subscribe sample context", subListener); } catch (MqttException e) { state = ERROR; donext = true; ex = e; } } } /** * Disconnect in a non-blocking way and then sit back and wait to be * notified that the action has completed. */ public class Disconnector { public void doDisconnect() { // Disconnect the client log("Disconnecting"); IMqttActionListener discListener = new IMqttActionListener() { public void onSuccess(IMqttToken asyncActionToken) { log("Disconnect Completed"); state = DISCONNECTED; carryOn(); } public void onFailure(IMqttToken asyncActionToken, Throwable exception) { ex = exception; state = ERROR; log ("Disconnect failed" +exception); carryOn(); } public void carryOn() { synchronized (waiter) { donext=true; waiter.notifyAll(); } } }; try { client.disconnect("Disconnect sample context", discListener); } catch (MqttException e) { state = ERROR; donext = true; ex = e; } } } }
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