1、导入依赖库：
implementation 'org.eclipse.paho:org.eclipse.paho.android.service:1.1.1'
implementation 'org.eclipse.paho:org.eclipse.paho.client.mqttv3:1.2.5'
2、功能封装：
package com.example.mqttdemo;
import static android.app.Service.START_NOT_STICKY;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Handler;
import android.os.IBinder;
import android.util.Log;
import androidx.annotation.Nullable;
import org.eclipse.paho.android.service.MqttAndroidClient;
import org.eclipse.paho.client.mqttv3.*;
public class MyMqttService extends Service {
public final static String TAG = MyMqttService.class.getSimpleName();
public static MqttAndroidClient mqttAndroidClient;
private static MqttConnectOptions mMqttConnectOptions;
public static String HOST = "tcp://broker.hivemq.com:1883";//服务器地址（协议+地址+端口号）
public String USERNAME = "";//用户名
public String PASSWORD = "";//密码
public static String PUBLISH_TOPIC = "/d";//发布主题
public static String RESPONSE_TOPIC = "v";//响应主题
public String CLIENTID = "CLIENTID";//设备唯一标识
public int onStartCommand(Intent intent, int flags, int startId) {
init();
return START_NOT_STICKY;//非粘性的 service强制杀死后，不会尝试重新启动service
}
public IBinder onBind(Intent intent) {
return null;
}
/**
* 开启服务
*/
public static void startService(Context mContext) {
mContext.startService(new Intent(mContext, MyMqttService.class));
}
/**
* 发布 （模拟其他客户端发布消息）
*
* @param message 消息
*/
public static void publish(String message) {
String topic = PUBLISH_TOPIC;
Integer qos = 1;
Boolean retained = false;
try {
//参数分别为：主题、消息的字节数组、服务质量、是否在服务器保留断开连接后的最后一条消息
mqttAndroidClient.publish(topic, message.getBytes(), qos.intValue(), retained.booleanValue());
} catch (MqttException e) {
e.printStackTrace();
}
}
/**
* 响应 （收到其他客户端的消息后，响应给对方告知消息已到达或者消息有问题等）
*
* @param message 消息
*/
public static void response(String message) {
String topic = RESPONSE_TOPIC;
Integer qos = 1;
Boolean retained = false;
try {
//参数分别为：主题、消息的字节数组、服务质量、是否在服务器保留断开连接后的最后一条消息
mqttAndroidClient.publish(topic, message.getBytes(), qos.intValue(), retained.booleanValue());
} catch (MqttException e) {
e.printStackTrace();
}
}
/**
* 初始化
*/
private void init() {
String serverURI = HOST; //服务器地址（协议+地址+端口号）
Log.i(TAG, "初始化MQ" + serverURI);
if (mqttAndroidClient == null) {
mqttAndroidClient = new MqttAndroidClient(this, serverURI, CLIENTID);
mqttAndroidClient.setCallback(mqttCallback); //设置监听订阅消息的回调
}
if (mMqttConnectOptions == null) {
mMqttConnectOptions = new MqttConnectOptions();
mMqttConnectOptions.setCleanSession(true); //设置是否清除缓存
mMqttConnectOptions.setConnectionTimeout(10); //设置超时时间，单位：秒
mMqttConnectOptions.setKeepAliveInterval(20); //设置心跳包发送间隔，单位：秒
mMqttConnectOptions.setUserName(USERNAME); //设置用户名
mMqttConnectOptions.setPassword(PASSWORD.toCharArray()); //设置密码
}
// last will message
boolean doConnect = true;
String message = "{\"terminal_uid\":\"" + CLIENTID + "\"}";
String topic = PUBLISH_TOPIC;
Integer qos = 1;
Boolean retained = true;
if ((!message.equals("")) || (!topic.equals(""))) {
// 最后的遗嘱
try {
mMqttConnectOptions.setWill(topic, message.getBytes(), qos.intValue(), retained.booleanValue());
} catch (Exception e) {
Log.i(TAG, "Exception Occured");
doConnect = false;
iMqttActionListener.onFailure(null, e);
}
}
if (doConnect) {
doClientConnection();
}
}
/**
* 连接MQTT服务器
*/
private static void doClientConnection() {
try {
if (!mqttAndroidClient.isConnected() && isConnectIsNomarl()) {
Log.i(TAG, "连接MQTT服务器" + HOST);
mqttAndroidClient.connect(mMqttConnectOptions, null, iMqttActionListener);
}
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 判断网络是否连接
*/
private static boolean isConnectIsNomarl() {
return true;
// ConnectivityManager connectivityManager = (ConnectivityManager) BaseApplication.getInstance().getSystemService(Context.CONNECTIVITY_SERVICE);
// NetworkInfo info = connectivityManager.getActiveNetworkInfo();
// if (info != null && info.isAvailable()) {
// String name = info.getTypeName();
// Log.i(TAG, "当前网络名称：" + name);
// return true;
// } else {
// Log.i(TAG, "没有可用网络");
// /*没有可用网络的时候，延迟3秒再尝试重连*/
// new Handler().postDelayed(new Runnable() {
// @Override
// public void run() {
// Log.i(TAG, "没有可用网络doClientConnection");
// doClientConnection();
// }
// }, 3000);
// return false;
// }
}
//MQTT是否连接成功的监听
private static IMqttActionListener iMqttActionListener = new IMqttActionListener() {
public void onSuccess(IMqttToken arg0) {
Log.i(TAG, "连接成功 " + HOST);
try {
if (mqttAndroidClient != null) {
mqttAndroidClient.subscribe(PUBLISH_TOPIC, 1);//订阅主题，参数：主题、服务质量
}
} catch (Exception e) {
e.printStackTrace();
}
}
public void onFailure(IMqttToken arg0, Throwable arg1) {
arg1.printStackTrace();
Log.i(TAG, "连接失败 ");
doClientConnection();//连接失败，重连（可关闭服务器进行模拟）
}
};
//订阅主题的回调
private MqttCallback mqttCallback = new MqttCallback() {
public void messageArrived(String topic, MqttMessage msgStr) throws Exception {
try {
String enCodeMsg = new String(msgStr.getPayload());
Log.i(TAG, "收到消息： " + enCodeMsg);
//收到消息，这里弹出Toast表示。如果需要更新UI，可以使用广播或者EventBus进行发送
//收到其他客户端的消息后，响应给对方告知消息已到达或者消息有问题等
response("message arrived");
} catch (Exception e) {
e.printStackTrace();
}
}
public void deliveryComplete(IMqttDeliveryToken arg0) {
}
public void connectionLost(Throwable arg0) {
Log.i(TAG, "连接断开 ");
doClientConnection();//连接断开，重连
}
};
public static void disconnect(Context context) {
try {
if (mqttAndroidClient != null && mqttAndroidClient.isConnected()) {
mqttAndroidClient.unsubscribe(PUBLISH_TOPIC);
mqttAndroidClient.unregisterResources();
mqttAndroidClient.disconnect(0); //断开连接
mqttAndroidClient = null;
context.stopService(new Intent(context, MyMqttService.class));
}
} catch (Exception e) {
e.printStackTrace();
}
}
}