I'm trying to setup a TCP connection between my Android phone and my Raspberry Pi. Should be easy, turns out it isn't ?

So i started writing a simple server with ServerSocket.

It didn't work so i reduced the code until i got this piece which is not working:

try

{

String wifiip = wifiIpAddress(this);

Log.v("SERVER", wifiip);

ServerSocket serverSocket = new ServerSocket();

serverSocket.setReuseAddress(true);

serverSocket.bind(new InetSocketAddress(wifiip, 4117));

}catch (Exception ex)

{

ex.printStackTrace();

}

(The code is located in the onCreate method in my MainActivity which was created by AndroidStudio)

I also tried to create the ServerSocket with this method with no success.

ServerSocket serverSocket = new ServerSocket(4117);

The method wifiIpAddress was taken from here: https://stackoverflow.com/a/18638588/2394967

and works just fine.

The AndroidManifest.xml

...

Maybe useful informations:

I'm running AndroidStudio on ArchLinux

I tried using a new, untouched Project

I tried different Ports (above 1024)

I'm running the App on a real device (Xperia Z, Android 5.0.2)

I tried running the ServerSocket in another thread

Logcat

java.net.SocketException: socket failed: EACCES (Permission denied)

W/System.err﹕ at libcore.io.IoBridge.socket(IoBridge.java:632)

W/System.err﹕ at java.net.PlainSocketImpl.create(PlainSocketImpl.java:198)

W/System.err﹕ at java.net.PlainServerSocketImpl.create(PlainServerSocketImpl.java:38)

W/System.err﹕ at java.net.ServerSocket.(ServerSocket.java:64)

W/System.err﹕ at eu.therealskynet.socketstest.MainActivity.onBtSendClicked(MainActivity.java:47)

W/System.err﹕ at java.lang.reflect.Method.invoke(Native Method)

W/System.err﹕ at java.lang.reflect.Method.invoke(Method.java:372)

W/System.err﹕ at android.view.View$1.onClick(View.java:4078)

W/System.err﹕ at android.view.View.performClick(View.java:4832)

W/System.err﹕ at android.view.View$PerformClick.run(View.java:19839)

W/System.err﹕ at android.os.Handler.handleCallback(Handler.java:739)

W/System.err﹕ at android.os.Handler.dispatchMessage(Handler.java:95)

W/System.err﹕ at android.os.Looper.loop(Looper.java:211)

W/System.err﹕ at android.app.ActivityThread.main(ActivityThread.java:5333)

W/System.err﹕ at java.lang.reflect.Method.invoke(Native Method)

W/System.err﹕ at java.lang.reflect.Method.invoke(Method.java:372)

W/System.err﹕ at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1016)

W/System.err﹕ at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:811)

W/System.err﹕ Caused by: android.system.ErrnoException: socket failed: EACCES (Permission denied)

W/System.err﹕ at libcore.io.Posix.socket(Native Method)

W/System.err﹕ at libcore.io.BlockGuardOs.socket(BlockGuardOs.java:282)

W/System.err﹕ at libcore.io.IoBridge.socket(IoBridge.java:617)

W/System.err﹕ ... 17 more

I don't even know what "socket failed: EACCES (Permission denied)" is supposed to tell me...