DatagramSocket receive() not receiving any data

Question

I have written an Android app that listen on UDP port 5150 to receive encoded audio stream from a device connected to same wifi router. However the call to receive() method is blocked indefinitely and does not receive any data.

int FRAME_SIZE = 480;
byte[] udpBuffer = new byte[FRAME_SIZE];
DatagramSocket socket;

socket = new DatagramSocket(5150);
datagramPacket = new DatagramPacket(udpBuffer, FRAME_SIZE);

System.out.println("Starting UDP listener");
for(;;){
        socket.receive(datagramPacket);
        System.out.println("receiving UDP data");
}

I have set the following permission

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

What could be the reason not to receive any UDP data?

I have a iOS application that can receive UDP data. Only Android having this issue. Therefore it is safe to assume data is sent by the source. — Jason Nanay, Jul 02 '18 at 11:46
There is nothing in the code you posted that even trlies to receive anything. Not proven. — user207421, Jul 02 '18 at 11:51
I'm using simple socket.receive(datagramPacket) in the code with sufficient exception handling. — Jason Nanay, Jul 02 '18 at 12:16
Not in this code. Code posted here is supposed to demonstrate the problem. This doesn't. — user207421, Jul 02 '18 at 16:51

Jason Nanay · Answer 1 · 2018-07-03T02:05:45.353

-1

The issue was due to the IP address returned by the device being in reverse order. As a result my device IP sent to server was incorrect making the server to send data to an incorrect destination. After fixing this I was able to receive data.

Thank you all for the support.

edited Jul 03 '18 at 02:05

answered Jul 03 '18 at 01:27

Jason Nanay

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What server? None mentioned in your question. Your question says the data is sent by a device, not a server. – user207421 Jul 03 '18 at 02:11

DatagramSocket receive() not receiving any data

1 Answers1