LibGDX - TCP for all platforms

Networking & Multiplayer
#1

Hello all,

First, I don’t know for 100% if this has to be in the java libraries section or here, but I thought it fitted the best here…

Ok, so I made a game with help of LibGDX, its a turn-based strategy, that I want to publish on android and iOS, and maybe on desktop…
Now I want to play against my grandma, so I need to make this multiplayer for at least android and iOS…

I had problems because the ClientSocket is working on java application, but was not working on my android emulator, this caused my error:
ClientSocket socketname = Gdx.net.newClientSocket(Protocol.TCP, “127.0.0.1”, 1337, hints);
I changed “127.0.0.1” (local host) to my internal ip “192.168.1.82” (static ip) and it worked.

Maybe some people are helped with this :wink:

#2

About the android app crash try adding this to the Android app’s manifest file:

I am also developing a game in LibGDX. Since I want to maintain full cross-platform I use this to create a socket:

Socket socket = Gdx.net.newClientSocket(Protocol.TCP, hostname, port, SocketHints hint)

The socket is Gdx.net.Socket
The hostname is a string
The port is an integer
The SocketHints are custom options for the socket, set it to null to use the system’s defaults

The socket has a getInputStream() and getOutputStream() methods which give you a java.io.InputStream and java.io.OutputStream

Hope this helps!

#3

Aha, so the TCP LibGDX provides works well on all platforms?
Sorry, so it is not lacking networking completely (UDP, UDP)

Android manifest must be the evil! :smiley:
I’m starting my android emulator now and I’m gonna try this!

Edit:
Ok, so I put it here:
<manifest

blabla..

And if I click at the Permissions tab I see: android.permission.INTERNET, so it seems all fine, but I still get the same error, Unfortunately myGame has stopped

What do I do wrong?

#4

Can you try to post the stacktrace from LogCat here, I can’t do much without it.

#5

Code:
SocketHints hints = new SocketHints();
server = Gdx.net.newClientSocket(Protocol.TCP, “127.0.0.1”, 1337, hints);
try {
server.getOutputStream().write(“Hello, baby!\n”.getBytes());
} catch (IOException e) {
Gdx.app.log(“OK”, “COULDNT WRITE TO SERVER!”);//just for debugging
}

07-29 20:02:07.336: I/ARMAssembler(847): generated scanline__00000177:03545444_00009001_00000000 [159 ipp] (215 ins) at [0x4cc0a1f0:0x4cc0a54c] in 2424793 ns
07-29 20:02:09.286: W/dalvikvm(847): threadid=11: thread exiting with uncaught exception (group=0x40a71930)
07-29 20:02:09.306: E/AndroidRuntime(847): FATAL EXCEPTION: GLThread 81
07-29 20:02:09.306: E/AndroidRuntime(847): com.badlogic.gdx.utils.GdxRuntimeException: Error making a socket connection to 127.0.0.1:1337
07-29 20:02:09.306: E/AndroidRuntime(847): at com.badlogic.gdx.backends.android.AndroidSocket.(AndroidSocket.java:55)
07-29 20:02:09.306: E/AndroidRuntime(847): at com.badlogic.gdx.backends.android.AndroidNet.newClientSocket(AndroidNet.java:87)
07-29 20:02:09.306: E/AndroidRuntime(847): at com.herjan.MultiPlayerMenu.(MultiPlayerMenu.java:20)
07-29 20:02:09.306: E/AndroidRuntime(847): at com.herjan.MenuInputHandler.touchUp(MenuInputHandler.java:48)
07-29 20:02:09.306: E/AndroidRuntime(847): at com.badlogic.gdx.backends.android.AndroidInput.processEvents(AndroidInput.java:359)
07-29 20:02:09.306: E/AndroidRuntime(847): at com.badlogic.gdx.backends.android.AndroidGraphics.onDrawFrame(AndroidGraphics.java:456)
07-29 20:02:09.306: E/AndroidRuntime(847): at android.opengl.GLSurfaceView$GLThread.guardedRun(GLSurfaceView.java:1516)
07-29 20:02:09.306: E/AndroidRuntime(847): at android.opengl.GLSurfaceView$GLThread.run(GLSurfaceView.java:1240)
07-29 20:02:09.306: E/AndroidRuntime(847): Caused by: java.net.ConnectException: failed to connect to /127.0.0.1 (port 1337) after 5000ms: isConnected failed: ECONNREFUSED (Connection refused)
07-29 20:02:09.306: E/AndroidRuntime(847): at libcore.io.IoBridge.isConnected(IoBridge.java:224)
07-29 20:02:09.306: E/AndroidRuntime(847): at libcore.io.IoBridge.connectErrno(IoBridge.java:161)
07-29 20:02:09.306: E/AndroidRuntime(847): at libcore.io.IoBridge.connect(IoBridge.java:112)
07-29 20:02:09.306: E/AndroidRuntime(847): at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:192)
07-29 20:02:09.306: E/AndroidRuntime(847): at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:459)
07-29 20:02:09.306: E/AndroidRuntime(847): at java.net.Socket.connect(Socket.java:842)
07-29 20:02:09.306: E/AndroidRuntime(847): at com.badlogic.gdx.backends.android.AndroidSocket.(AndroidSocket.java:48)
07-29 20:02:09.306: E/AndroidRuntime(847): … 7 more
07-29 20:02:09.306: E/AndroidRuntime(847): Caused by: libcore.io.ErrnoException: isConnected failed: ECONNREFUSED (Connection refused)
07-29 20:02:09.306: E/AndroidRuntime(847): at libcore.io.IoBridge.isConnected(IoBridge.java:208)
07-29 20:02:09.306: E/AndroidRuntime(847): … 13 more
07-29 20:02:14.906: I/Process(847): Sending signal. PID: 847 SIG: 9

From these copied messages: first was green, then orange, then all red, except the last (green) one

#6

Is the server running on the computer you are running the emulator from? If it is try using the computers internal ip address (ex: 192.168.1.x) instead of localhost

#7

Wauw, thanks, that works, LOL!

Epic error… Whole day f**ked up because of… THIS… Just searched everywhere for solutions, is it this… Im curious, why this error, what caused this error?

#8

It has to do with the emulator itself. I learned this after spending two hours doing trial and error on a rcon client for android just to find the emulator caused it. Glad to here it works. Good luck on your game!

#9

Thanks, just stay checking this forum, I will post it in the WIP section when the game is ready for it :wink: