在這個資訊時代，大數據、AI、物聯網等等技術蓬勃發展。人手一支的智慧型手機，也改變了許多人們的生活習慣，交友、連絡方式等等，以往人與人見面聊天的互動模式，也逐漸被通訊軟體給取代。時至今日，通訊軟體已經不只被拿來用於閒聊聯繫感情，人們也用它來討論公事，甚至交辦工作事項、傳送公司內部公文文件等等，也因此，通訊軟體的隱私問題也日益重要。而市面上常見的通訊軟體皆為無法自行重製的套裝軟體，其數據傳輸、通訊方式，資料儲存等，均掌握於開發的公司，因而具敏感資訊或機密訊息的隱私性不易受到保障。基於資訊安全的需求，國內外大型的公司或機構，便著手進行發展私有的通訊平台
且近年來不斷蓬勃發展的，各式各樣的手機應用程式(APP, application)，不論是客服專區，或是手機遊戲中玩家們彼此的溝通聯絡，交友軟體的配對與對話等等，也都需要有自己的聊天平台。
而常見於物聯網的傳輸協定「訊息序列遙測傳輸」(MQTT, Message Queuing Telemetry Transport)不只適用於物聯網，它的訂閱/發布的訊息推播機制，也同樣適合用於聊天平台裡。
本論文結合手機APP以及物聯網傳輸協定MQTT，以HiveMQ為MQTT server，自己設計主題架構，並以Android Studio自行編寫手機端應用程式，實作一個聊天APP。

In this thesis, the content is divided into two parts: implementation of a chatting platform by using MQTT internet protocol (sever part), and development of the chatting APP (client part). For the server part, the review of MQTT, including description of the MQTT mechanisms, the “subscribe/publish” message spreading mechanism, topic level & topic level wildcard, and MQTT package types, etc are first introduced. Then the adopted server, HiveMQ, is described, including method of building HiveMQ server and extension of its functions. Lastly, one of the adopted extensions—RBAC extension and the self-design topic level structure are illustrated. For the client part, the APP developing software, Android Studio is introduced first. Then the mechanisms used in this APP, such as activity, recyclerView, SQLite, etc are written. Lastly, the functionality of the APP and the mechanisms used in the APP are explained.
At the end, after verifying and analyzing the feasibility of the chatting platform, the working principle of the MQTT chatting platform and the user friendly interface of the APP are successfully developed.

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