Cannot connect to RabbitMQ Server from remote machine (Android device)

问题

I've started RabbitMQ server on my local machine (Windows 10). Management panel on localhost:5672 is working well. I've established new user and wrote example project in java for sending and receiving. It works well with localhost and with my ip address for new established user:

Unfortunately i've written the same configuration in my Android project and error appears:

12-27 00:42:04.601 4393-4393/com.gornik.sendsensors E/AndroidRuntime: FATAL EXCEPTION: main
                                                                  Process: com.gornik.sendsensors, PID: 4393
                                                                  android.os.NetworkOnMainThreadException
                                                                      at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1273)
                                                                      at libcore.io.BlockGuardOs.connect(BlockGuardOs.java:110)
                                                                      at libcore.io.IoBridge.connectErrno(IoBridge.java:154)
                                                                      at libcore.io.IoBridge.connect(IoBridge.java:122)
                                                                      at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:183)
                                                                      at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:452)
                                                                      at java.net.Socket.connect(Socket.java:884)
                                                                      at com.rabbitmq.client.impl.FrameHandlerFactory.create(FrameHandlerFactory.java:47)
                                                                      at com.rabbitmq.client.ConnectionFactory.newConnection(ConnectionFactory.java:822)
                                                                      at com.rabbitmq.client.ConnectionFactory.newConnection(ConnectionFactory.java:778)
                                                                      at com.rabbitmq.client.ConnectionFactory.newConnection(ConnectionFactory.java:868)
                                                                      at com.gornik.sendsensors.SendMessages.connectAndPublishMessage(SendMessages.java:27)
                                                                      at com.gornik.sendsensors.MainActivity$1.onClick(MainActivity.java:25)
                                                                      at android.view.View.performClick(View.java:5702)
                                                                      at android.view.View$PerformClick.run(View.java:22541)
                                                                      at android.os.Handler.handleCallback(Handler.java:739)
                                                                      at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                      at android.os.Looper.loop(Looper.java:158)
                                                                      at android.app.ActivityThread.main(ActivityThread.java:7229)
                                                                      at java.lang.reflect.Method.invoke(Native Method)
                                                                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
                                                                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)

"connectAndPublishMessage" method:

public static void connectAndPublishMessage(String serverIPAddress) throws IOException{
    ConnectionFactory factory = new ConnectionFactory();
    factory.setHost("IP ADDRESS");
    factory.setUsername("NEWUSER");
    factory.setPassword("USERPASSWORD");
    factory.setVirtualHost("/");
    factory.setPort(5672);
    try {
        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();
        channel.queueDeclare(QUEUE_NAME, false, false, false, null);
        String message = "Hello world";
        channel.basicPublish("", QUEUE_NAME, null, message.getBytes("UTF-8"));
        Log.d("MESSAGE SENT: ", " [x] Sent '" + message + "'");

        channel.close();
        connection.close();
    }catch(TimeoutException e){
        e.printStackTrace();
    }
}

Can You figure out why it is different on my local machine and on Android device? How can i connect with my Android device to remote RabbitMQ server?

回答1:

Try adding these two lines:

StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);

回答2:

Thanks @Shubham Agarwal for resolving the problem :) For future purposes - to be sure it is working correctly i had to keep an eye on few things:

1. correct configuration - ip address, port(default 5672), virtual host("/")
2. new user as default "guest" can only connect to localhost
3. change boolean parameter in queue.declare() function to true
4. add two lines about thread policy.

来源：https://stackoverflow.com/questions/41337444/cannot-connect-to-rabbitmq-server-from-remote-machine-android-device