Benpian record it chose to develop and test MQTT server, client, JAVA client
MQTT server selection and installation process;
MQTT client test tool installation and testing;
MQTT JAVA client selection and development, testing,
MQTT server selection and installation
The current mainstream open source server MQTT mainly the following three:
1) EMQX : GitHub 4882 Stars
2) mosquitto : 1645 Stars GitHub
3) Apollo : an upgraded version of ActiveMQ, github 109 stars
We chose this MQTT EMQX as a server, first go to EMQ official website to download EMQX installed version, up to now the latest version to V4.0.4
See the examiner network installation steps given help documentation
According to the official website operation can not start the service, card emqx start over here in
this step is very pit, be sure to install the system needs a good ERLANG development environment, ERLANG jump address , probably because EMQX is ERLANG to explain or develop
After starting the installation is complete, if it is installed in the machine, you can open in a browser http://127.0.0.1 : 18083, enter the default username "admin" and the default password "public", can successfully enter the Admin Console Help EMQX server installation is complete.
MQTT client installation and testing
Client testing tools recommended MQTTBox
MQTTBox There are two ways: one for Chrome plug-in; another installation program for Windows.
1) Chrome Chrome plug-in plug-ins directly to the market to search mqttbox (over the wall needed)
2) Windows installation package here: Download
MQTT server connection:
Referring next to FIG disposed connection server, protocol selection mqtt / tcp; Host port 1883;
other temporarily affect test parameters, its own research interest.
Successfully connect to the server, Connected icon will be displayed in green
Add a subscriber
Orders topic is "hello"; Qos is the default 0
Add a publisher
Post a topic for the "hello" message period { "hello": "world"}, Qos default 0
News release, subscribers will receive this message window immediately. At this point, the client test is complete.
MQTT JAVA client development and testing
JAVA client selects
EMQX SDK_TOOLS open source client tools under development in almost all the languages listed. JAVA SDK currently under the main Eclipse Paho, Xenqtt, MeQanTT, mqtt -client.
Because a Spring Integration Endpoints to connect officially supported DEMO is used inside Eclipse Paho, so this time we chose the JAVA client is Eclipse Paho.
POM introduced
<dependency>
<groupId>org.eclipse.paho</groupId>
<artifactId>org.eclipse.paho.client.mqttv3</artifactId>
<version>1.2.0</version>
</dependency>
Examples of release-side development
1 import org.eclipse.paho.client.mqttv3.MqttClient; 2 import org.eclipse.paho.client.mqttv3.MqttConnectOptions; 3 import org.eclipse.paho.client.mqttv3.MqttException; 4 import org.eclipse.paho.client.mqttv3.MqttMessage; 5 import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence; 6 7 /** 8 * 发布端未例 9 */ 10 public class PublishSample { 11 public static void main(String[] args) { 12 13 Topic = String "MQTT / OKOK" ; 14 String Content = "Hello ha. 1" ; 15 int QoS =. 1 ; 16 String Broker = "TCP: //127.0.0.1: 1883" ; . 17 String the userName = "Test" ; 18 is password = String "Test" ; . 19 String clientId = "pubClient1" ; 20 is // memory storage 21 is MemoryPersistence Persistence = new new MemoryPersistence (); 22 is 23 is the try { 24 // create a client 25 SampleClient = MqttClient new new MqttClient (Broker, clientId, Persistence); 26 // create a link parameter 27 MqttConnectOptions connOpts = new new MqttConnectOptions (); 28 // remember the state upon reboot and reconnect 29 connOpts.setCleanSession ( false ); 30 // set the name of the user connection 31 is connOpts.setUserName (the userName); 32 connOpts.setPassword (password.toCharArray ()); 33 is // establish a connection 34 is sampleClient.connect (connOpts); 35 // create message 36 Message = MqttMessage new new MqttMessage (content.getBytes ()); 37 [ // set quality of service message 38 is message.setQos (QoS); 39 // release message 40 sampleClient.publish (Topic, Message); 41 is // disconnect 42 is sampleClient.disconnect (); 43 is // Close the client 44 is sampleClient.close (); 45 } the catch (MqttException Me) { 46 is System.out.println ( "reason" + me.getReasonCode ()); 47 the System.out .println ( "msg" + me.getMessage()); 48 System.out.println("loc " + me.getLocalizedMessage()); 49 System.out.println("cause " + me.getCause()); 50 System.out.println("excep " + me); 51 me.printStackTrace(); 52 } 53 } 54 }
Subscribe to end publication instance
1 import org.eclipse.paho.client.mqttv3.*; 2 import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence; 3 4 /** 5 * 订阅端 6 */ 7 public class SubscribeSample { 8 public static void main(String[] args) throws MqttException { 9 String HOST = "tcp://127.0.0.1:1883"; 10 String TOPIC = "mqtt/okok"; 11 int qos = 1; 12 String clientid = "subClient1"; 13 is String the userName = "Test" ; 14 String = passWord, "Test" ; 15 the try { 16 // Host name is the host, the client ID for Test clientid connected MQTT i.e., generally represents the unique identifier to the client, MemoryPersistence provided clientid storage format, the default is to save memory . 17 MqttClient Client = new new MqttClient (the HOST, clientid, new new MemoryPersistence ()); 18 is // connected MQTT provided . 19 MqttConnectOptions Options = new new MqttConnectOptions (); 20 is // settings are empty session here If set to false indicates that the server retains the client's connection record, set here to represent true every time you connect to the server are connected to a new identity 21 options.setCleanSession ( to true ); 22 is // username provided connection 23 is options.setUserName (the userName); 24 // password connection 25 options.setPassword (passWord.toCharArray ()); 26 is // set the timeout time is sec 27 options.setConnectionTimeout (10 ); 28 // set the session seconds heartbeat message server sends the client determines whether the line to the client every 1.5 * 20 seconds, but this method does not reconnection mechanism 29 options.setKeepAliveInterval (20 is ); 30 // set the callback function 31 is client.setCallback ( new new MqttCallback () { 32 33 @Override 34 public void connectionLost(Throwable cause) { 35 System.out.println("connectionLost"); 36 } 37 38 @Override 39 public void messageArrived(String topic, MqttMessage message) throws Exception { 40 System.out.println("topic:"+topic); 41 System.out.println("Qos:"+message.getQos()); 42 System.out.println("message content:"+new String(message.getPayload())); 43 44 } 45 46 @Override 47 public void deliveryComplete(IMqttDeliveryToken token) { 48 System.out.println("deliveryComplete---------"+ token.isComplete()); 49 } 50 51 }); 52 client.connect(options); 53 //订阅消息 54 client.subscribe(TOPIC, qos); 55 } catch (Exception e) { 56 e.printStackTrace(); 57 } 58 } 59 }
Next: the MQTT integrated into Spring Mvc
More Reference website:
1.EMQX Help Center https://docs.emqx.io/broker/latest/cn/
2.Spring the MQTT Support https://docs.spring.io/spring-integration/docs/5.0.8.RELEASE/reference/ html / mqtt.html