Test your knowledge

1. The Eclipse Paho Java Client provides:

   1. Only a blocking (synchronous) API.

   2. Only a non-blocking (asynchronous) API.

   3. Both a blocking (synchronous) and a non-blocking (asynchronous) API.

2. In the Paho Java API, an instance of MqttAsyncClient represents:

   1. The synchronous MQTT client.

   2. The asynchronous MQTT client.

   3. The asynchronous MQTT message.

3. After the MqttAsyncClient instance establishes a connection with the MQTT server, which of the following methods declared in the IMqttActionListener interface will be called?

   1. onSuccess.

   2. connectCallback.

   3. onConnect.

4. After the MqttAsyncClient instance receives a message from one of the topic filters to which it has subscribed, which of the following methods declared in the MqttCallback interface will be called?

   1. onSuccess.

   2. onMessage.

   3. messageArrived.

5. Which of the following methods of an MqttConnectOptions instance allows you to set a last will message?

   1. setLastWillMessage.

   2. setLastWill.

   3. setWill.