How to make my Java SpringBoot application to proxy MQTT Broker WebSocket 8083 port? - spring

Question

Let's suppose we have an Spring Boot application called A. And we have a MQTT Broker that supports MQTT WebSocket Service.
The device used to connect directly to the MQTT Broker's 8083 port to get MQTT WebSocket Service. But now I want the device to connect to the A's 80 port to get the same MQTT WebSocket Service. For example, the device connect to the ws://A_HOST:80/mqtt, it should work the same as it connect to ws://MQTT_BROKER_HOST:8083/mqtt.
My solution is to use the org.springframework.web.reactive.socket.WebSocketHandler in A. When device connect to A, I would use org.springframework.web.reactive.socket.client.ReactorNettyWebSocketClient in A to connect to MQTT Broker at the same time. Whatever data the device sends to A, the A should send the same data to the MQTT Broker. And Whatever the data MQTT Broker responses(or sends), the A should send the same data to device. I think the solution can implement my needs.
I am using WebFlux.
I write the code below, but unfortunately it doesn't work:
public class ReactiveWebSocketHandler implements WebSocketHandler {
#Override
public Mono<Void> handle(WebSocketSession serverSession) {
WebSocketClient client = new ReactorNettyWebSocketClient();
client.execute(
URI.create("ws://xxx.0.0.1:8083/mqtt"), // xxx.0.0.1:8083 is the MQTT Broker Address
new WebSocketHandler() {
#Override
public List<String> getSubProtocols() {
return Collections.singletonList("mqtt");
}
#Override
public Mono<Void> handle(WebSocketSession clientSession) {
return clientSession.send(serverSession.receive()) // Whatever data the device sends to A, the A should send the same data to the MQTT Broker
.and(
serverSession.send(clientSession.receive())); // Whatever the data MQTT Broker responses(or sends), the A should send the same data to device
}
});
return Mono.empty(); // Since I have written the logic above, I don't know what should I write here
}
#Override
public List<String> getSubProtocols() {
return Collections.singletonList("mqtt");
}
}
Could you tell me how to write the code that can implements such logic? Thanks!