The micro broker supports two types of messaging for communicating with its clients and with other brokers. The first uses messages built according to the MQTT protocol (details of which are publicly available), while the second uses the Java Messaging Service (JMS) API specification.
The micro broker MQTT client is designed for applications that need a lightweight but functional protocol. It includes the following functionality:
- Designed to support specialized embedded applications, particularly in constrained environments
- Uses the MQTT pervasive messaging protocol
- Supports both publish/subscribe and point-to-point messaging paradigms
- Supports retained publications
- Provides a raw byte message format with user defined header properties
- Offers no support for application control of transactions or message selectors
- Provides three Quality of Service (QoS) for message delivery as per the MQTT specification
- Provides an optimized proprietary programming model
- Implements a listener callback pattern for delivery of messages, loss of network connectivity, and so on
Two versions of the MQTT client are provided: the client that was available in previous releases of Lotus Expeditor that supports version 3 of the MQTT protocol and a client that supports version 5 of the MQTT protocol.
The MQTT V3 client is provided for compatibility with existing applications. Use of the MQTT v5 client is encouraged due to its enhanced capabilities.
The JMS interface is well documented in the Sun specification.
Parent topic: Understanding messaging applications: XPD621