![](\"https:\/\/i.cdn.yimenapp.com\/2023-03\/20\/18\/05521274651.jpg\")
<\/figure>\n<\/p>\n`<\/p>\n
3. \u5b9e\u73b0\u56de\u8c03\u63a5\u53e3\uff1a\u6dfb\u52a0\u56de\u8c03\u63a5\u53e3 `MqttCallback`:<\/p>\n
“`java<\/p>\n
public class MQTTManager implements MqttCallback {<\/p>\n
\/\/…MQTTManager\u7684\u5176\u4ed6\u4ee3\u7801<\/p>\n
public void setCallback() {<\/p>\n
mqttAndroidClient.setCallback(this);<\/p>\n
}<\/p>\n
@Override<\/p>\n
public void connectionLost(Throwable cause) {<\/p>\n
\/\/ \u8fde\u63a5\u4e22\u5931\uff0c\u53ef\u4ee5\u5728\u8fd9\u91cc\u5904\u7406\u76f8\u5173\u903b\u8f91<\/p>\n
}<\/p>\n
@Override<\/p>\n
public void messageArrived(String topic, MqttMessage message) throws Exception {<\/p>\n
\/\/ \u6536\u5230\u6d88\u606f\uff0cAPP<\/a>\u53ef\u4ee5\u5728\u8fd9\u91cc\u5904\u7406\u76f8\u5173\u903b\u8f91<\/p>\n
public void deliveryComplete(IMqttDeliveryToken token) {<\/p>\n
4. \u8fde\u63a5\u3001\u8ba2\u9605\u3001\u53d1\u5e03\uff1a<\/p>\n
public class MQTTManager {<\/p>\n
\/\/ \u5b9e\u73b0\u8fde\u63a5<\/p>\n
public void connect(final IMqttActionListener listener) {<\/p>\n
IMqttToken token = mqttAndroidClient.connect();<\/p>\n
token.setActionCallback(listener);<\/p>\n
} catch (MqttException e) {<\/p>\n
\/\/ \u8ba2\u9605\u4e3b\u9898<\/p>\n
public void subscribe(String topic) {<\/p>\n
mqttAndroidClient.subscribe(topic, 0);<\/p>\n
} catch (MqttException e) {<\/p>\n
\/\/ \u53d1\u5e03\u6d88\u606f<\/p>\n
public void publish(String topic, String message) {<\/p>\n
MqttMessage mqttMessage = new MqttMessage();<\/p>\n
mqttMessage.setPayload(message.getBytes());<\/p>\n
mqttAndroidClient.publish(topic, mqttMessage);<\/p>\n
} catch (Exception e) {<\/p>\n