I currently have an API in SpringBoot and I would like to add an MQTT client to subscribe to one or more topics.
I tried several Paho,Hive clients, without success, I'm currently on the default MQTT of SpringBoot which uses Paho but I can't get it to work even with the basic configuration.
I get a "Connection Lost" error as soon as I launch the application...
Can you tell me a fix or something else that would work. Thanks!
Maven :
<dependency>
<groupId>org.springframework.integration</groupId>
<artifactId>spring-integration-mqtt</artifactId>
</dependency>
....
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.integration.annotation.ServiceActivator;
import org.springframework.integration.channel.DirectChannel;
import org.springframework.integration.core.MessageProducer;
import org.springframework.integration.mqtt.inbound.MqttPahoMessageDrivenChannelAdapter;
import org.springframework.integration.mqtt.support.DefaultPahoMessageConverter;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageChannel;
import org.springframework.messaging.MessageHandler;
import org.springframework.messaging.MessagingException;
import lombok.extern.slf4j.Slf4j;
import springfox.documentation.swagger2.annotations.EnableSwagger2;
@Slf4j
@SpringBootApplication
@EnableSwagger2
public class MainApiSpring {
public static void main(String[] args) {
SpringApplication.run(MainApiSpring.class, args);
log.trace("L'application a correctement été démarrée.");
}
@Bean
public MessageChannel mqttInputChannel() {
return new DirectChannel();
}
@Bean
public MessageProducer inbound() {
MqttPahoMessageDrivenChannelAdapter adapter = new MqttPahoMessageDrivenChannelAdapter("tcp://localhost:1883",
"test/topic");
adapter.setCompletionTimeout(5000);
adapter.setConverter(new DefaultPahoMessageConverter());
adapter.setQos(1);
adapter.setOutputChannel(mqttInputChannel());
return adapter;
}
@Bean
@ServiceActivator(inputChannel = "mqttInputChannel")
public MessageHandler handler() {
return new MessageHandler() {
@Override
public void handleMessage(Message<?> message) throws MessagingException {
System.out.println(message.getPayload());
}
};
}
}
The error on run :
2020-09-04 10:31:39.099 ERROR 4244 --- [ main] .m.i.MqttPahoMessageDrivenChannelAdapter : Exception while connecting and subscribing, retrying
org.eclipse.paho.client.mqttv3.MqttException: Connexion perdue
at org.eclipse.paho.client.mqttv3.internal.CommsReceiver.run(CommsReceiver.java:197) ~[org.eclipse.paho.client.mqttv3-1.2.4.jar:na]
at java.base/java.lang.Thread.run(Thread.java:830) ~[na:na]
Caused by: java.io.EOFException: null
at java.base/java.io.DataInputStream.readByte(DataInputStream.java:272) ~[na:na]
at org.eclipse.paho.client.mqttv3.internal.wire.MqttInputStream.readMqttWireMessage(MqttInputStream.java:92) ~[org.eclipse.paho.client.mqttv3-1.2.4.jar:na]
at org.eclipse.paho.client.mqttv3.internal.CommsReceiver.run(CommsReceiver.java:137) ~[org.eclipse.paho.client.mqttv3-1.2.4.jar:na]
... 1 common frames omitted