MQTT PUBLISHER AND SUBSCRIBER

Sample Spring Boot application that publishes message to a topic on mqtt server and receives messages from specific topics.

Before Run And Compile

You should change publisherId and server url from

src/main/java/com/gulteking/mqttbackendserver/config/Mqtt.java

Edit Lines Below(publisher id optional):

private static final String MQTT_PUBLISHER_ID = "spring-server";  
private static final String MQTT_SERVER_ADDRES= "tcp://127.0.0.1:1883";

Compile and Run(in pom.xml)

mvn clean install
java -jar target/mqtt-backend-server-0.0.1-SNAPSHOT.jar

Publish message(POST: /api/mqtt/publish)

{
	"message": "testMessage",
	"topic":"test",
	"retained":true,
	"qos":0
}

Subscribe Messages From a Topic For X Milliseconds

GET: /api/mqtt/subscribe?topic=test&wait_millis=5000

Returns message array after 5 seconds:

[
    {
        "message": "testMessage",
        "qos": 0,
        "id": 0
    }
]

MQTT SERVER DOCKER

You can also set up an Eclipse Mosquitto server(https://hub.docker.com/_/eclipse-mosquitto) with docker.

If you didn't set up container before, enter project's main folder and type:

docker-compose up -d

If you have already setup container,

docker-compose start

to stop;

docker-compose stop