Message transmitting and receiving method, communication apparatus, and program

A non-transitory computer readable medium storing a computer program, the computer program comprising a middleware and a library, the middleware, when executed by a computer, causing the computer to operate as a middleware unit configured to manage a message published by a publisher in a publish/subscribe system in which a message is exchanged between the publisher and a subscriber via a broker, the library including functions configured to provide the broker wherein the computer program is executed by the computer to provide the steps of:

• performing, by a middleware unit, subscribing on the broker by setting a callback function;
• upon receipt of a first message published by a first device, passing, by the broker, the first message to the middleware unit by calling the callback function;
• and
• transmitting, by the middleware unit, the first message to a second device in response to receipt of the first message from the broker.

A communication apparatus comprising:

• a processor;
• a memory coupled to the processor, the memory being configured to store a middleware and a library, the middleware, when executed by the processor, causing the processor to operate as a middleware unit configured to manage a message published by a publisher in a publish/subscribe system in which a message is exchanged between the publisher and a subscriber via a broker,
• the library including functions configured to provide the broker,
• wherein the middleware unit is further configured to perform subscribing on the broker by setting a callback function,
• wherein the broker is configured to, upon receipt of a first message published by a first device, pass the first message to the middleware unit by calling the callback function, and
• wherein the middleware unit is configured to, in response to receipt of the first message from the broker, transmit the first message to a second device.