安卓MQTT基本使用
一在 build.gradle 添加相应依赖
implementation 'org.eclipse.paho:org.eclipse.paho.client.mqttv3:1.1.1'
implementation 'org.eclipse.paho:org.eclipse.paho.android.service:1.1.1'二、添加权限
三、配置订阅信息 （订阅信息更具你的实际情况进行修改)
package com.example.myapplication;
public class Api {
public static String host="tcp://192.168.9.2:1885";
public static String userName="admin";
public static String passWord="password";
public static String mqtt_id="mqtt_brokerr";
public static String mqtt_sub_topic="{app}/set/request/database/model";订阅主题
public static String mqtt_pub_topic="2548444745_esp";//发布主题
}Mactivity
package com.example.myapplication;
import androidx.appcompat.app.AppCompatActivity;
import android.annotation.SuppressLint;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import org.eclipse.paho.client.mqttv3.IMqttDeliveryToken;
import org.eclipse.paho.client.mqttv3.MqttCallback;
import org.eclipse.paho.client.mqttv3.MqttClient;
import org.eclipse.paho.client.mqttv3.MqttConnectOptions;
import org.eclipse.paho.client.mqttv3.MqttException;
import org.eclipse.paho.client.mqttv3.MqttMessage;
import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
public class MainActivity extends AppCompatActivity {
private int led_flag = 1;
private ScheduledExecutorService scheduler;
private Button btn_1;
private TextView text_test;
private MqttClient client;
private MqttConnectOptions options;
private Handler handler;
@SuppressLint("HandlerLeak")
@Override
protected void onCreate(Bundle savedInstanceState) {
//这里是界面打开后 最先运行的地方
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btn_1 = findViewById(R.id.btn_1);
btn_1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (led_flag == 0) {
publishmessageplus(mqtt_pub_topic, "{\"set_led\":1}");
led_flag = 1;
} else {
publishmessageplus(mqtt_pub_topic, "{\"set_led\":0}");
led_flag = 0;
}
}
});
text_test = findViewById(R.id.text_test);
//**********************************************************//
Mqtt_init();
startReconnect();
handler = new Handler() {
@SuppressLint("SetTextI18n")
public void handleMessage(Message msg) {
super.handleMessage(msg);
switch (msg.what) {
case 1:
break;
case 2:
break;
case 3:
Log.d("收到消息回传==============: ", msg.toString());
//在主进程 handler 里面更新UI 既保证了稳定性 又不影响网络传输
text_test.setText(msg.toString());
break;
case 30: //连接失败
Toast.makeText(MainActivity.this, "连接失败", Toast.LENGTH_SHORT).show();
Log.d("连接状态", "连接失败");
break;
case 35: //连接成功
Toast.makeText(MainActivity.this, "连接成功", Toast.LENGTH_SHORT).show();
Log.d("连接状态", "连接成功");
//订阅主题
try {
client.subscribe(Api.mqtt_sub_topic, 1);
} catch (MqttException e) {
e.printStackTrace();
}
break;
default:
break;
}
}
};
}
/***
* MQTT 初始化
*/
private void Mqtt_init() {
try {
//host为主机名，test为clientid即连接MQTT的客户端ID，一般以客户端唯一标识符表示，MemoryPersistence设置clientid的保存形式，默认为以内存保存
client = new MqttClient(Api.host, Api.mqtt_id,
new MemoryPersistence());
//MQTT的连接设置
options = new MqttConnectOptions();
//设置是否清空session,这里如果设置为false表示服务器会保留客户端的连接记录，这里设置为true表示每次连接到服务器都以新的身份连接
options.setCleanSession(false);
options.setUserName(Api.userName);
options.setPassword(Api.passWord.toCharArray());
// 设置超时时间 单位为秒
options.setConnectionTimeout(10);
// 设置会话心跳时间 单位为秒 服务器会每隔1.5*20秒的时间向客户端发送个消息判断客户端是否在线，但这个方法并没有重连的机制
options.setKeepAliveInterval(20);
//设置回调
client.setCallback(new MqttCallback() {
@Override
public void connectionLost(Throwable cause) {
//连接丢失后，一般在这里面进行重连
Log.d("连接状态", "连接丢失");
startReconnect();
}
@Override
public void deliveryComplete(IMqttDeliveryToken token) {
//publish后会执行到这里
Log.d("连接状态", "交付完成:" + token.isComplete());
}
@Override
public void messageArrived(String topicName, MqttMessage message)
throws Exception {
//subscribe后得到的消息会执行到这里面
Log.d("连接状态", "消息到达");
Message msg = new Message();
//封装message包
msg.what = 3; //收到消息标志位
msg.obj = message.toString();
//发送messge到handler
handler.sendMessage(msg);
}
});
} catch (Exception e) {
e.printStackTrace();
}
}
/***
* MQTT 连接
*/
private void Mqtt_connect() {
new Thread(new Runnable() {
@Override
public void run() {
try {
if (!(client.isConnected())) //如果还未连接
{
client.connect(options);
Message msg = new Message();
msg.what = 35;
handler.sendMessage(msg);
}
} catch (Exception e) {
e.printStackTrace();
Message msg = new Message();
msg.what = 30;
handler.sendMessage(msg);
}
}
}).start();
}
/***
* 开始重新连接
*/
private void startReconnect() {
scheduler = Executors.newSingleThreadScheduledExecutor();
scheduler.scheduleAtFixedRate(new Runnable() {
@Override
public void run() {
if (!client.isConnected()) {
Mqtt_connect();
}
}
}, 0 * 1000, 10 * 1000, TimeUnit.MILLISECONDS);
}
/***
* 发布消息加
* @param topic
* @param message2
*/
private void publishmessageplus(String topic, String message2) {
if (client == null || !client.isConnected()) {
return;
}
MqttMessage message = new MqttMessage();
message.setPayload(message2.getBytes());
try {
client.publish(topic, message);
} catch (MqttException e) {
e.printStackTrace();
}
}
}
布局代码