Question

我刚开始学习使用Android Studio的MQTT协议。使用 mosquitto 代理，我可以在 pub / sub 窗口之间交换消息。但是当我通过android studio向经纪人发送消息时，该应用程序构建成功，但在经纪人的终端上没有显示任何内容。系统打印连接失败。相同的代码在eclipse java应用程序上运行正常，但是在Android上没有工作，尽管已经添加了所需的库和依赖项。

请帮助，我在这个基本步骤中缺少什么，这样我才能向前学习。谢谢！

应用-的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'

}

项目的build.gradle

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

的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>

HomeActivity

  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，所以你需要两个库来在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代替MqttClient。

new MqttAndroidClient(...)。

我发布了一个完整的Android MQTT服务示例here，如果有帮助的话。

编辑：完整活动示例

创建新MemoryPersistence时添加了

（1）MqttAndroidClient （2）在.connect()（MqttAndroidClient和mqttConnectOptions）的null方法中添加了两个参数。
（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

我想添加评论，但我的代表太低了......所以我将其作为答案发布。

你说你有一切正常但由于IllegalArgumentException无法连接。我遇到了同样的问题，发现你还需要定义协议。因此，而不是"192.168.0.103:1883"尝试：

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：

修改AndroidManifest.xml以包含：
- <service android:name="org.eclipse.paho.android.service.MqttService" /> （来自application标签内）
- <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" />
修改build.gradle以包含（在dependencies部分中）：
- compile 'org.eclipse.paho:org.eclipse.paho.client.mqttv3:1.1.1'
- compile 'org.eclipse.paho:org.eclipse.paho.android.service:1.1.1'
使用MqttAndroidClient（不是MqttClient）

将您的代码放入＆＃34; onSuccess＆＃34;回调，以避免由于方法异步导致的任何问题（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设备上的MQTT发布者遇到了相同的问题。在从Android模拟器引用tcp://localhost:1883时，我不得不使用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

我遇到了相同的错误，但是我已经解决了。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" />

应用程序内部的服务标签：

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

活动代码：

 MqttAndroidClient client;
 Button btnsub,btnpublish;

与Mqtt客户端连接：

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，请点击：

   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 {
                        }
                    });

要发布按钮，请点击：

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

Android Studio - MQTT无法连接

4 个答案: