Source link: https://github.com/itsJoKr/LocalNetwork

LocalNetwork

Local network library for connecting Android devices on WiFi. One device serves as a server, others are clients. Library takes care of discovery of server by clients. Library uses services and separate threads with sockets to handle communication.

Wi-Fi Aware

In new O Developer Preview, Android team created something called Wi-Fi aware, and you might want to check that out: https://developer.android.com/preview/features/wifi-aware.html

This library is nowhere near done. But you can get it from jcenter if you want:

compile 'com.github.jokr:localnet:0.1'

Usage

There are two main parts of this library: server and client. One device should be server and others should be clients. Server uses LocalServer class, and clients LocalClient class.

There are two phases: discovery and session. In discovery phase client devices discover server on wifi.

Discovery | Client

Client should start LocalClient instance and call connect(). You will probably want to setDiscoveryReceiver(*DiscoveryStatusReceiver impl*) then you can get notified if server is discovered successfully. You will be also notified when server starts session.

public interface DiscoveryStatusReceiver {

public void onDiscoveryTimeout();

public void onServerDiscovered();

public void onSessionStart();

  
}

Discovery | Server

Server should start LocalServer instance and call init(). From there it is listening for clients to discover it.

localServer = new LocalServer(getContext());
 localServer.init();

You can receive information when client connects by providing receiver in localServer.setReceiver method.

 @Override
  public void onClientConnected(Payload<?> payload) {

// do something
  
}

You will see a lot of Payload<?> through this library. It is basically a way for library to send any your object. Make your own class implements Serializable and pack it with Payload: new Payload<YourClass>(new YourClass(...)).

Once you are ready to end discovery and start session call localServer.setSession(*LocalSesion impl) and discovery phase ends and session starts.

LocalSession class

Main part of session is LocalSession class. This is abstract class you should extend and implement all session/game logic here. This code will run in service. Main methods to override are:

 @Override
  public void onCreate(Bundle bundle, ConnectedClients connectedClients){

// session is created
  
}

@Override
  public void onReceiveMessage(long recipientId, Payload payload) {

// received message from client
  
}

@Override
  public void onEvent(Payload<?> payload) {

// received event from LocalServer instance
  
}

From here you can call sendMessage(long recipientId, Payload<?> payload) to send message to client, or sendBroadcastMessage(Payload<?> payload) to send message to all clients. You can also send message to your LocalServer instance and then possibly show it on UI with sendUiEvent(Payload<?> payload)

Session | Server

To start a session, just call localServer.setSession(*LocalSesion impl*) and provide implementation as descibed above. Just like you can send events from your LocalSession to LocalServer, you can send events other way - from LocalServer to your LocalSession implementation by calling localServer.sendLocalSessionEvent(Payload<?>) and this will call onEvent method in your LocalSession.

Session | Client

Client can send messages to server by calling localClient.sendSessionMessage(Payload<?>) and receive messages from server by setting receiver:

localClient.setReceiver(new LocalClient.MessageReceiver() {

 @Override

 public void onMessageReceived(Payload<?> payload) {

  // Payload has object you've sent from LocalSession

 
}

}
);