Wifi-Connect

A simple wrapper module to connect two devices and share data using Wifi-Direct.

This library provides an easy way to access the wifi direct api provided by Android without having to deal with all the boilerplate stuff going on inside.

dependencies {
    implementation 'com.wifiscanner:wifiscanner:0.1.2'
}

Maven Dependecy - Java

<dependency>
  <groupId>com.wifiscanner</groupId>
  <artifactId>wifiscanner</artifactId>
  <version>0.1.2</version>
  <type>pom</type>
</dependency>

<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

Declare the following service:

<service android:enabled="true" android:name="com.wifiscanner.server.ServerDataService" />

Note: Currently the app does not support runtime permissions.

Step 2: Define the wrapper class in the onCreate() method of the activity

WifiP2PService wifiP2PService = new WifiP2PServiceImpl.Builder()
                .setSender(this)
                .setWifiP2PConnectionCallback(this)
                .build();
        wifiP2PService.onCreate();

We need to initialize the wrapper class and declare the activity as either the Sender or the Receiver. For instance, in order to declare the activity as a Sender class, we use .setSender(this). In order to declare the activity as a Receiver class, we use .setReceiver(this)

The Receiver - will act as the server. It will fetch the list of available nearby devices and select a device to connect with. The Sender - will act as the client. Once a connection request is made from the server, the sender will accept the connection and pass data to the Receiver

Step 3: Add the following method in the onResume method of the activity

wifiP2PService.onResume();

This method will register the broadcast receiver that will listen for the changes in Wifi network.

Step 4: Add the following method in the onStop method of the activity

wifiP2PService.onStop();

This method will unregister the broadcast receiver since the activity is no longer at the top of the activity.

Step 5: Implement the WifiP2PConnectionCallback interface in your activity

public class MainActivity extends AppCompatActivity implements WifiP2PConnectionCallback {

Functions in the WifiP2PConnectionCallback interface

Function Name	Usage
initiateDiscovery()	This callback method is called when the scan is first initiated
onDiscoverySuccess()	This callback method is called the discovery is successful
onDiscoveryFailure()	This callback method is called the discovery is not successful
onPeerAvailable()	This callback method is called with a list of all peer available devices
onPeerStatusChanged()	This status of the peers that are discovered is changing
onPeerConnectionSuccess()	called when a connection to a nearby device is successful
onPeerConnectionFailure()	called when a connection to a nearby device is not successful
onPeerDisconnectionSuccess()	called when a disconnection to a nearby device is successful
onPeerDisconnectionFailure()	called when a disconnection to a nearby device is not successful
onDataTransferring()	called when data transfer has been initiated
onDataTransferredSuccess()	called when data transfer has completed & is successful
onDataTransferredFailure()	called when data transfer has completed & is not successful
onDataReceiving()	Called when the receiver has started to receive the data from sender
onDataReceivedSuccess(String message)	Called when the receiver has received the data successfully
onDataReceivedFailure()	Called when the data transferred is completed but data is not received

Methods available in the Receiver class: Method to connect to an available device: - you need to pass the device that is to be connected wifiP2PService.connectDevice(wifiP2pDevice);

Method to start data transfer - you need to pass the message that needs to be shared to the client wifiP2PService.startDataTransfer("Helllooo");

And that's it folks!