hono-spring

Hono Spring Integration

The hono spring integration makes eclipse/hono very easy to use with spring-boot and spring-cloud-stream.

Hono Spring Boot Autoconfiguration

The hono-spring-autoconfiguration autoconfigures a hono-client as spring bean automatically based on the hono-client properties.

hono.client.host=###honoHost###
hono.client.password=###secret###
hono.client.username=###secret###
hono.client.tlsEnabled=true

Hono Spring Cloud Stream Binder

The hono-cloud-stream-binder is an implementation of the binder integration into spring-cloud-stream.

spring.cloud.stream.bindings.input.binder=hono
spring.cloud.stream.hono.tenant=###my hono tenant####

Currently the message sent on the cloud-stream-bus are only String based. Check out the HonoInboundChannelAdapter

private Void handleMessage(final Message msg) {
   final String deviceId = MessageHelper.getDeviceId(msg);
   final String content = ((Data) msg.getBody()).getValue().toString();
   LOG.info("received message [device: {}, content-type: {}]: {}", deviceId, msg.getContentType(), content);
   sendMessage(getMessageBuilderFactory().withPayload(content).build());
   return null;
}

Spring Boot Test-Application

Simple App

The hono-spring-testapp just uses the hono spring integration dependency to start a spring-boot app and test the spring-cloud-stream binder implementation. This allows to consume telementry very easily by using the spring-cloud-stream abstraction like:

package org.micha.honotestapp;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.stream.annotation.EnableBinding;
import org.springframework.cloud.stream.annotation.StreamListener;
import org.springframework.cloud.stream.messaging.Sink;

@SpringBootApplication
@EnableBinding(Sink.class)
public class HonoTestAppApplication {

    public static void main(final String[] args) {
        SpringApplication.run(HonoTestAppApplication.class, args);
    }

    @StreamListener(Sink.INPUT)
    public void handle(final String input) {
        System.out.println("Retrieved Input : " + input);
    }

}

Websocket Transformation

The hono-spring-websocket-testapp makes use of the spring-cloud-stream-binder-hono to consume hono telemetry messages and forward it to a websocket interface consumed by the example application as well and showing on the simple javascript app on localhost:8080

@SpringBootApplication
@EnableBinding(Sink.class)
public class HonoTestAppApplication {

    @Autowired
    private SimpMessagingTemplate template;

    public static void main(final String[] args) {
        SpringApplication.run(HonoTestAppApplication.class, args);
    }

    @StreamListener(Sink.INPUT)
    public void handle(final String input) {
        template.convertAndSend("/topic/message", input);
    }
}