我刚刚开始学习在 Android Studio 中使用 MQTT 协议(protocol)。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 向代理发送消息时,应用程序构建成功但代理端没有显示任何内容,系统打印连接失败。相同的代码在 eclipse java 应用程序上运行良好,但在 android 上运行不正常,尽管已添加了所需的库和依赖项。
请帮忙,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'
}
project-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>
主页 Activity
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) {
}
}
}
最佳答案
我只想添加评论,但我的代表太低...所以我将其作为答案发布。
您说您已使一切正常,但由于 IllegalArgumentException
而无法连接.我遇到了同样的问题,发现您还需要定义协议(protocol)。
所以而不是 "192.168.0.103:1883"
尝试:
String serverURI = "tcp://192.168.0.103:1883"
根据我的阅读,您已经完成了其他必要的步骤,但为了给出完整的答案:
编辑
AndroidManifest.xml
包括:<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" />
编辑
build.gradle
包括(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'
使用
MqttAndroidClient
(不是MqttClient
)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 } });
关于Android Studio - MQTT 未连接,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/43038597/