Android Studio - MQTT 未连接

Question

我刚刚开始学习在 Android Studio 中使用 MQTT 协议。 使用mosquitto代理，我能够在发布/订阅窗口之间交换消息。 但是，当我通过 android studio 向代理发送消息时，应用程序构建成功，但代理端没有任何显示，系统打印连接失败。 相同的代码在 eclipse java 应用程序上运行良好，但在 android 上不起作用，尽管已添加所需的库和依赖项。

请帮助，我在这个基本步骤中缺少什么，以便我可以继续学习。 谢谢！

app-build.gradle

    dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.android.support:appcompat-v7:25.2.0'
    compile 'com.android.support.constraint:constraint-layout:1.0.2'
    testCompile 'junit:junit:4.12'

// have added following dependencies

    provided 'com.google.android.things:androidthings:0.2-devpreview'
    provided 'com.google.android.things:androidthings:0.1-devpreview'
    compile 'org.eclipse.paho:org.eclipse.paho.client.mqttv3:1.0.2'

}

项目-build.gradle

   repositories {
            jcenter()
            maven {
                url "https://repo.eclipse.org/content/repositories/paho-snapshots/"
            }    
}

AndroidManifest.xml

 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.zoha.mqttandroidiot">

    <!-- Permissions the Application Requires -->
    <uses-permission android:name="android.permission.WAKE_LOCK" />
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.READ_PHONE_STATE" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />


    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">


        <activity android:name=".HomeActivity">

            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>
                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>

            <!-- Launch activity automatically on boot -->
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>
                <category android:name="android.intent.category.IOT_LAUNCHER"/>
                <category android:name="android.intent.category.DEFAULT"/>
            </intent-filter>

        </activity>
<service android:name="org.eclipse.paho.android.service.MqttService"/>

    </application>

</manifest>

家庭活动

  public class HomeActivity extends AppCompatActivity{

    MqttAndroidClient client;
   // private static final MemoryPersistence persistence = new MemoryPersistence();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        final MqttAndroidClient mqttAndroidClient = new MqttAndroidClient(this.getApplicationContext(), "tcp://localhost:1883", "androidSampleClient");
        mqttAndroidClient.setCallback(new MqttCallback() {
            @Override
            public void connectionLost(Throwable cause) {
                System.out.println("Connection was lost!");

            }

            @Override
            public void messageArrived(String topic, MqttMessage message) throws Exception {
                System.out.println("Message Arrived!: " + topic + ": " + new String(message.getPayload()));

            }

            @Override
            public void deliveryComplete(IMqttDeliveryToken token) {
                System.out.println("Delivery Complete!");
            }
        });

        try {
            mqttAndroidClient.connect(null, new IMqttActionListener() {
                @Override
                public void onSuccess(IMqttToken asyncActionToken) {
                    System.out.println("Connection Success!");
                    try {
                        System.out.println("Subscribing to /test");
                        mqttAndroidClient.subscribe("/test", 0);
                        System.out.println("Subscribed to /test");
                        System.out.println("Publishing message..");
                        mqttAndroidClient.publish("/test", new MqttMessage("Hello world testing..!".getBytes()));
                    } catch (MqttException ex) {

                    }

                }

                @Override
                public void onFailure(IMqttToken asyncActionToken, Throwable exception) {
                    System.out.println("Connection Failure!");
                }
            });
        } catch (MqttException ex) {

        }


    }
    }

Answer 1

好的，所以您需要两个库才能在 Android 中使用 MQTT。 一个是 mqtt paho 客户端，另一个是 Android 服务库。

compile 'org.eclipse.paho:org.eclipse.paho.android.service:1.0.2'
compile 'org.eclipse.paho:org.eclipse.paho.client.mqttv3:1.0.2'

然后，使用MqttAndroidClient而不是MqttClient 。

new MqttAndroidClient(...) 。

如果有帮助，我在这里发布了一个完整的 Android MQTT 服务示例。

编辑：完整活动示例

（1） MemoryPersistence创建新加入时MqttAndroidClient 。
(2) MqttAndroidClient ( .connect()方法中添加了两个参数（ mqttConnectOptions和null ）。
(3) 另外，在onFailure()上打印错误

public class HomeActivity extends AppCompatActivity {

    private MqttAndroidClient client;
    private final MemoryPersistence persistence = new MemoryPersistence();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        final MqttAndroidClient mqttAndroidClient = new MqttAndroidClient(this.getApplicationContext(), "tcp://localhost:1883", "androidSampleClient", persistence);
        mqttAndroidClient.setCallback(new MqttCallback() {
            @Override
            public void connectionLost(Throwable cause) {
                System.out.println("Connection was lost!");
            }

            @Override
            public void messageArrived(String topic, MqttMessage message) throws Exception {
                System.out.println("Message Arrived!: " + topic + ": " + new String(message.getPayload()));
            }

            @Override
            public void deliveryComplete(IMqttDeliveryToken token) {
                System.out.println("Delivery Complete!");
            }
        });

        MqttConnectOptions mqttConnectOptions = new MqttConnectOptions();
        mqttConnectOptions.setCleanSession(true);

        try {
            mqttAndroidClient.connect(mqttConnectOptions, null, new IMqttActionListener() {
                @Override
                public void onSuccess(IMqttToken asyncActionToken) {
                    System.out.println("Connection Success!");
                    try {
                        System.out.println("Subscribing to /test");
                        mqttAndroidClient.subscribe("/test", 0);
                        System.out.println("Subscribed to /test");
                        System.out.println("Publishing message..");
                        mqttAndroidClient.publish("/test", new MqttMessage("Hello world testing..!".getBytes()));
                    } catch (MqttException ex) {

                    }
                }

                @Override
                public void onFailure(IMqttToken asyncActionToken, Throwable exception) {
                    System.out.println("Connection Failure!");
                    System.out.println("throwable: " + exception.toString());
                }
            });
        } catch (MqttException ex) {
            System.out.println(ex.toString());
        }
    }
}

Answer 2

我只想添加评论，但我的代表太低了...所以我将其发布为答案。

你说你一切正常，但由于IllegalArgumentException无法连接。 我遇到了同样的问题，发现您还需要定义协议。 所以不要尝试"192.168.0.103:1883" ：

String serverURI = "tcp://192.168.0.103:1883"

从我读到的你已经做了其他必要的步骤，但为了给出一个完整的答案：

1. 编辑AndroidManifest.xml以包括：

   • <service android:name="org.eclipse.paho.android.service.MqttService" /> （从application标签内部）

   • <uses-permission android:name="android.permission.INTERNET" />

   • <uses-permission android:name="android.permission.WAKE_LOCK" />
   • <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
   • <uses-permission android:name="android.permission.READ_PHONE_STATE" />

2. 编辑build.gradle以包含（在dependencies部分）：

   • compile 'org.eclipse.paho:org.eclipse.paho.client.mqttv3:1.1.1'

   • compile 'org.eclipse.paho:org.eclipse.paho.android.service:1.1.1'

3. 使用MqttAndroidClient （不是MqttClient ）

4. 将您的代码放在“onSuccess”回调中，以避免由于方法异步而导致的任何问题（如 THEPATEL 的回答所示）：

    MqttConnectOptions mqttConnectOptions = new MqttConnectOptions(); mqttConnectOptions.setKeepAliveInterval(60);//seconds mqttConnectOptions.setCleanSession(true); mqttConnectOptions.setAutomaticReconnect(true); mqttAndroidClient.connect(mqttConnectOptions, null, new IMqttActionListener() { @Override public void onSuccess(IMqttToken asyncActionToken) { //Treat success here (subscribe, publish etc) } @Override public void onFailure(IMqttToken asyncActionToken, Throwable exception) { //Treat failure here } });

Answer 3

我在 Android 设备上遇到了 MQTT 发布者同样的问题。 在从 android 模拟器引用tcp://localhost:1883 ，我必须使用http://10.0.2.2:1883因为模拟器在其自己的 VM 上运行，而 localhost 将是模拟器自己的环回地址。

Answer 4

我遇到了同样的错误，但我已经解决了。 这是工作代码。

在 gradle 中：

compile 'org.eclipse.paho:org.eclipse.paho.client.mqttv3:1.1.0'
    compile 'org.eclipse.paho:org.eclipse.paho.android.service:1.1.0'

在清单中：

  <uses-permission android:name="android.permission.WAKE_LOCK" />
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.READ_PHONE_STATE" />

应用程序内的服务标签：

  <service android:name="org.eclipse.paho.android.service.MqttService" >
        </service>

活动代码：

 MqttAndroidClient client;
 Button btnsub,btnpublish;

连接 Mqtt 客户端：

String clientId = MqttClient.generateClientId();
   client = new MqttAndroidClient(getApplicationContext(), "tcp://www.domain.in/ip:11883",clientId);
        client.connect().setActionCallback(new IMqttActionListener() {
            @Override
            public void onSuccess(IMqttToken asyncActionToken) {
                // We are connected
            }
            @Override
            public void onFailure(IMqttToken asyncActionToken, Throwable exception) {
            }
        });

要订阅按钮单击：

   client.subscribe("topic", 0, null, new IMqttActionListener() {
                        @Override
                        public void onSuccess(IMqttToken asyncActionToken) {
                        }
                        @Override
                        public void onFailure(IMqttToken asyncActionToken, Throwable exception) {
                        }
                    });
                    client.subscribe("topic", 0, new IMqttMessageListener() {
                        @Override
                        public void messageArrived(String topic, MqttMessage message) throws Exception {
                        }
                    });

点击按钮发布：

   MqttMessage message = new MqttMessage();
                    message.setPayload("message".getBytes());
                    client.publish("topic", message);