一，在app下的build.gradle中添加如下引用

implementation 'org.eclipse.paho:org.eclipse.paho.client.mqttv3:1.1.0'//mqtt相关

implementation 'org.eclipse.paho:org.eclipse.paho.android.service:1.1.1'//mqtt相关

implementation 'org.greenrobot:eventbus:3.1.1'//eventBus 为了传数据会UI界面

二，AndroidManifest.xml中添加权限

在application中添加如下代码

三，MyMqttService类

public class MyMqttService extends Service {

public final String TAG = MyMqttService.class.getSimpleName();

private static MqttAndroidClient mqttAndroidClient;

private MqttConnectOptions mMqttConnectOptions;

public String HOST = "tcp://192.168.101.115:1883";//服务器地址(协议+地址+端口号)

public String USERNAME = "admin";//用户名

public String PASSWORD = "admin";//密码

public static String PUBLISH_TOPIC = "tourist_enter";//发布主题

public static String RESPONSE_TOPIC = "message_arrived";//响应主题

public String CLIENTID = "zhangrenwen";

// public String CLIENTID = Build.VERSION.SDK_INT >= Build.VERSION_CODES.O

// ? Build.getSerial() : Build.SERIAL;//客户端ID，一般以客户端唯一标识符表示，这里用设备序列号表示

@Override

public int onStartCommand(Intent intent, int flags, int startId) {

init();

return super.onStartCommand(intent, flags, startId);

}

@Nullable

@Override

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 = 2;

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("GBK"), qos.intValue(), retained.booleanValue());

} catch (Exception 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 void response(String message) {

String topic = RESPONSE_TOPIC;

Integer qos = 2;

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)

mqttAndroidClient = new MqttAndroidClient(this, serverURI, CLIENTID);

mqttAndroidClient.setCallback(mqttCallback); //设置监听订阅消息的回调

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 = 2;

Boolean retained = false;

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", e);

doConnect = false;

iMqttActionListener.onFailure(null, e);

}

}

if (doConnect) {

doClientConnection();

}

}

/**

* 连接MQTT服务器

*/

private void doClientConnection() {

if (!mqttAndroidClient.isConnected() && isConnectIsNomarl()) {

try {

mqttAndroidClient.connect(mMqttConnectOptions, null, iMqttActionListener);

} catch (MqttException e) {

e.printStackTrace();

}

}

}

/**

* 判断网络是否连接

*/

private boolean isConnectIsNomarl() {

ConnectivityManager connectivityManager = (ConnectivityManager) this.getApplicationContext().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() {

doClientConnection();

}

}, 3000);

return false;

}

}

//MQTT是否连接成功的监听

private IMqttActionListener iMqttActionListener = new IMqttActionListener() {

@Override

public void onSuccess(IMqttToken arg0) {

Log.i(TAG, "连接成功 ");

try {

mqttAndroidClient.subscribe(PUBLISH_TOPIC, 2);//订阅主题，参数：主题、服务质量

} catch (MqttException e) {

e.printStackTrace();

}

}

@Override

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() {

@Override

public void messageArrived(String topic, MqttMessage message) throws Exception {

Log.i(TAG, "收到消息： " + topic + new String(message.getPayload(),"GBK"));

EventBus.getDefault().post(new UpdateTextEvent(new String(message.getPayload(),"GBK")));

//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

// Toast.makeText(getApplicationContext(), "messageArrived: " + new String(message.getPayload()), Toast.LENGTH_LONG).show();

//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");

}

@Override

public void deliveryComplete(IMqttDeliveryToken arg0) {

}

@Override

public void connectionLost(Throwable arg0) {

Log.i(TAG, "连接断开 ");

doClientConnection();//连接断开，重连

}

};

@Override

public void onDestroy() {

try {

mqttAndroidClient.disconnect(); //断开连接

Log.i(TAG, "onDestroy: 服务关闭");

} catch (MqttException e) {

e.printStackTrace();

}

super.onDestroy();

}

}

四，封装数据bean类

public class UpdateTextEvent {

private static final String TAG = "AA";

private String msg;

public UpdateTextEvent(String msg) {

this.msg = msg;

Log.i(TAG, "updateTextEvent: " + msg);

}

public String getMsg() {

return msg;

}

public void setMsg(String msg) {

this.msg = msg;

}

}

五，activity_main.xml布局

xmlns:app="http://schemas.android.com/apk/res-auto"

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="match_parent"

android:layout_height="match_parent"

tools:context=".MainActivity">

android:id="@+id/editText"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="Hello World!"

app:layout_constraintBottom_toBottomOf="parent"

app:layout_constraintLeft_toLeftOf="parent"

app:layout_constraintRight_toRightOf="parent"

app:layout_constraintTop_toTopOf="parent" />

android:id="@+id/button"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="发送"

app:layout_constraintTop_toBottomOf="@+id/editText"

app:layout_constraintLeft_toLeftOf="parent"

app:layout_constraintRight_toRightOf="parent"

/>

android:id="@+id/textView"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="Hello World!"

app:layout_constraintTop_toBottomOf="@+id/button"

app:layout_constraintLeft_toLeftOf="parent"

app:layout_constraintRight_toRightOf="parent"

/>

六，MainActivity代码

public class MainActivity extends AppCompatActivity {

TextView textView;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

final EditText editText = findViewById(R.id.editText);

textView = findViewById(R.id.textView);

MyMqttService.startService(this); //开启服务

findViewById(R.id.button).setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

MyMqttService.publish(editText.getText().toString());

}

});

}

/**

* 订阅的过程中，默认是在主线程中用到的

*/

@Subscribe(threadMode = ThreadMode.MAIN)

public void modifyBtn4(UpdateTextEvent msg) {

textView.setText("收到的消息："+msg.getMsg());

}

@Override

public void onStart() {

super.onStart();

//在事件被订阅的界面中注册EventBus

EventBus.getDefault().register(this);

}

@Override

public void onStop() {

super.onStop();

//注销EventBus

EventBus.getDefault().unregister(this);

}

}

至此 已经完毕 但是想要测试效果请联系后台

我们根据后台修改以下框框内容就好

QQ截图20190828151833.png