How to develop a REST api to send response received from subscribed topic

ANJ · March 19, 2022, 6:13am

I Want to develop a SpringBoot application that will provide me with a REST endpoint. eg: GET /status, to get the online status of a device.

The HiveMQ client publishes a message with the topic name called device/get_status. And subscribed to a topic called device/response_status to listen to the device online status. Once the response is received to the subscribed topic the application will send the HTTP response of the device status.

Here I am facing difficulty to send the response received in the callback method. Any suggestions…

Daria_H · March 21, 2022, 4:05pm

Hi @ANJ ,

Thanks for your interest in MQTT and HiveMQ. Please be welcome in our community!

For us to understand the issue better, could you perhaps share your source code here and point out the problematic point in the callback method? If you are seeing an error please share with us what the error says.

Thank you,
Kind regards,
Dasha from HiveMQ Team

Daria_H · April 20, 2022, 9:11am

Hi @ANJ ,

We have a nice example for implementation of the Request - Respons pattern that comes with our Open-source HiveMQ client library:

github.com

hivemq/hivemq-mqtt-client/blob/master/examples/src/main/java/com/hivemq/client/mqtt/examples/RequestResponse.java

/*
 * Copyright 2018-present HiveMQ and the HiveMQ Community
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.hivemq.client.mqtt.examples;

import com.hivemq.client.mqtt.datatypes.MqttQos;
import com.hivemq.client.mqtt.mqtt5.Mqtt5Client;

This file has been truncated. show original

I hope this helps improve your code,
Kind regards,
Dasha

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How to develop a REST api to send response received from subscribed topic

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