WiFi P2P network in Android Things

2017-11-29 08:07 Antonio La Marra imported from Stackoverflow

I would like to create a P2P WiFi network using Android Things (5.1) and a couple of Raspberry Pi 3 or alternatively using Bluetooth. I followed the guide in the Android Developer section https://developer.android.com/guide/topics/connectivity/wifip2p.html, so my MainActivity looks like:

private class MainActtivity { private WifiP2pManager mManager; .... @Override public void onCreate(Bundle savedInstances) { mManager = (WifiP2pManager) getSystemService(Context.WIFI_P2P_SERVICE); .... } }

However when I try to run the app, with WiFI enabled, the SystemServiceRegistry shows a message stating

No service published for: wifip2p

and the WifiP2pManager is not retrieved.

How can I solve this issue? Does anybody know if it is possible to create a WiFi P2P network using WiFi Direct and Android Things?

See also questions close to this topic

WI-Fi turned on disables Bluetooth search Android

Some kind of strange, but when I have Wifi turned on my app doesn't show up with Bluetooth search for devices.

I Have the following permissions askings and in the manifest:

            Manifest.permission.ACCESS_COARSE_LOCATION,
            Manifest.permission.WRITE_EXTERNAL_STORAGE,
            Manifest.permission.ACCESS_FINE_LOCATION,
            Manifest.permission.ACCESS_WIFI_STATE,
            Manifest.permission.ACCESS_NETWORK_STATE

<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="
android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />
<uses-permission android:name="android. 
  permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.
  permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.
  permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE"/>
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.
 permission.CHANGE_CONFIGURATION" />
<uses-permission android:name="android.
 permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.
  permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.
  permission.UPDATE_DEVICE_STATS"/>

Something is missing, because when wifi is turned off, everything works as designed and in the end wi-fi is needed.

Have anyone had this issue?

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I have my mobile connected to a wifi access point. My laptop cannot connect to it as the adapter is poor. I have connected to the phone via bluetooth tether and have the internet working on my laptop :-) However, I want to share that bluetooth network connection with the rest of my LAN. When you right click the bluetooth network connection in Windows 7, it doesn't give the usual option in properties to share via Internet Connection Sharing. There's also no option to bridge the LAN and bluetooth networking adapters.... any ideas!?
Bluetooth Beacon packets

I am studying attendance system using beacon. The attendance system emits an advertising signal from the beacon when the class begins, and the students use the smartphone application to notify them that they are listening. So I captured the packets to probe for beacon packets. However, I was able to capture beacon packets in the classroom as well as beacons in other classrooms. I used the Wireshark to capture the sample packets to find the packets I wanted, and compared the UUID, Major, and Minor values of the beacon signals in the classroom or classroom, but they did not have anything in common. 1. Can the UUID, Major, and Minor values of the packets advertised in the beacon be randomly emitted at a given time?
Is there a way to deploy/debug a Cordova Android Ionic app through WiFi?

This is a twin of this question (originally for iOS).

I would like to deploy and debug my Ionic app to an Android device connected via WiFi and not via USB with my PC, that is a device that I can reach just with WiFi.

Is this possible?
Switching between different internet connection providers with Raspberry Pi

I'm working with a Raspberry Pi 3 B and there are multiple internet connection options:

1) Regular Wi-fi connection

2) 3g modem USB dongle

3) ethernet cable connection

I want my system to be able to switch between these 3 modes. For example: Rasp is connected via Wi-fi, but then the connection gets a bit unstable. I want to develop a software or something that would check whether one of the other options is faster and more stable, and then switch to the best mode. Is it possible?

Thanks in advance.

java.lang.NullPointerException: Attempt to invoke virtual method 'int java.io.InputStream.read(byte[])' on a null object reference

I am trying to create Chat Application using WiFip2p.Everything is done in this application. Before send and receive message app was working good. After that i got this error. I am getting this error when I connect to another device. It shows null object reference. I don't know why I need a solution can anyone help me thank you.

public class WiFi_Activity extends AppCompatActivity {


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_wi_fi_);

    FINDVIEWBYID();
    CLICKLISTINER();
}


Handler handler=new Handler(new Handler.Callback() {
    @Override
    public boolean handleMessage(Message msg) {

        switch (msg.what)
        {
            case MESSAGE_READ:

                byte[]  readbuffer=(byte[])msg.obj;
                String tempmez=new String(readbuffer,0,msg.arg1);
                txt_message.setText(tempmez);
                break;
        }

        return true;
    }
});

private void FINDVIEWBYID() {

        btn_onoff=findViewById(R.id.onOff);
        btn_discover=findViewById(R.id.discover);
        btn_send=findViewById(R.id.sendButton);
        listView=findViewById(R.id.peerListView);
        txt_connectionsts=findViewById(R.id.connectionStatus);
        txt_message=findViewById(R.id.readMsg);
        edit_message=findViewById(R.id.writeMsg);

    wifiManager= (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);

    wifiP2pManager= (WifiP2pManager) getSystemService(Context.WIFI_P2P_SERVICE);

    channel=wifiP2pManager.initialize(this,getMainLooper(),null);

    broadcastReceiver=new Wifi_broadcast_reciever(wifiP2pManager,channel,this);

    intentFilter=new IntentFilter();

    intentFilter.addAction(wifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION);
    intentFilter.addAction(wifiP2pManager.WIFI_P2P_PEERS_CHANGED_ACTION);
    intentFilter.addAction(wifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION);
    intentFilter.addAction(wifiP2pManager.WIFI_P2P_THIS_DEVICE_CHANGED_ACTION);

}
private void CLICKLISTINER() {

    btn_onoff.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {


            if (wifiManager.isWifiEnabled())
            {
                wifiManager.setWifiEnabled(false);
                btn_onoff.setText("ON");
            }
            else
            {
                wifiManager.setWifiEnabled(true);
                btn_onoff.setText("OFF");
            }

        }
    });

    btn_discover.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            wifiP2pManager.discoverPeers(channel, new WifiP2pManager.ActionListener() {
                @Override
                public void onSuccess() {

                    txt_connectionsts.setText("Discovery Started");
                }

                @Override
                public void onFailure(int reason) {

                    txt_connectionsts.setText("Discovery starting failuree"+String.valueOf(reason));
                }
            });
        }
    });

    listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
             final  WifiP2pDevice wifiP2pDevice=devicearray[position];
            WifiP2pConfig config=new WifiP2pConfig();
            config.deviceAddress=wifiP2pDevice.deviceAddress;
            wifiP2pManager.connect(channel, config, new WifiP2pManager.ActionListener() {
                @Override
                public void onSuccess() {

                    Toast.makeText(WiFi_Activity.this, "Connect with"+ wifiP2pDevice.deviceName, Toast.LENGTH_SHORT).show();
                }

                @Override
                public void onFailure(int reason) {

                    Toast.makeText(WiFi_Activity.this, "Not connected", Toast.LENGTH_SHORT).show();
                }
            });
        }
    });

    btn_send.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            String msz=edit_message.getText().toString();
            sendRecieve.write(msz.getBytes());
        }
    });
}

WifiP2pManager.PeerListListener peerListListener=new WifiP2pManager.PeerListListener() {
    @Override
    public void onPeersAvailable(WifiP2pDeviceList peerslist) {

        if (!peerslist.getDeviceList().equals(peers));
        {
            peers.clear();
            peers.addAll(peerslist.getDeviceList());

            devicename_array=new String[peerslist.getDeviceList().size()];
            devicearray=new WifiP2pDevice[peerslist.getDeviceList().size()];
            int index= 0;

             for (WifiP2pDevice device:peerslist.getDeviceList())
             {
                 devicename_array[index]=device.deviceName;
                 devicearray[index]=device;
                 index++;
             }

             ArrayAdapter<String> arrayAdapter=new ArrayAdapter<String>(getApplicationContext(),R.layout.support_simple_spinner_dropdown_item,devicename_array);
             listView.setAdapter(arrayAdapter);
        }

        if (peers.size()==0)
        {
            Toast.makeText(WiFi_Activity.this, "No discover show", Toast.LENGTH_SHORT).show();
        }
    }
};

WifiP2pManager.ConnectionInfoListener connectionInfoListener=new WifiP2pManager.ConnectionInfoListener() {
    @Override
    public void onConnectionInfoAvailable(WifiP2pInfo info) {

        final InetAddress owneraddress= info.groupOwnerAddress;

        if (info.groupFormed && info.isGroupOwner)
        {
            txt_connectionsts.setText("Host");
            serverclass=new Serverclass();
            serverclass.start();
        }
        else if (info.groupFormed)
        {
            txt_connectionsts.setText("Client");
            clientclass = new Clientclass(owneraddress);
            clientclass.start();

        }
    }
};

@Override
protected void onResume() {
    super.onResume();
    registerReceiver(broadcastReceiver,intentFilter);
}

@Override
protected void onPause() {
    super.onPause();
    unregisterReceiver(broadcastReceiver);
}

public class Serverclass extends Thread
{
    Socket socket;
    ServerSocket serverSocket;

    @Override
    public void run() {

        try {
            serverSocket=new ServerSocket(1111);
            socket=serverSocket.accept();
            sendRecieve=new SendRecieve(socket);
            sendRecieve.start();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

public class Clientclass extends Thread
{

    Socket socket;
    String host_address;

    public Clientclass(InetAddress hostaddress){

        host_address=hostaddress.getHostAddress();
        socket=new Socket();
        sendRecieve=new SendRecieve(socket);
        sendRecieve.start();
    }

    @Override
    public void run() {

        try {
            socket.connect(new InetSocketAddress(host_address,1111),500);


        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

private class SendRecieve extends Thread
{
    private Socket socket;
    private InputStream inputStream;
    private OutputStream outputStream;

    public SendRecieve(Socket skt)
    {

        socket=skt;

        try {
            inputStream=socket.getInputStream();
            outputStream=socket.getOutputStream();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void run() {

        byte[] buffer=new byte[2048];
        int bytes;

        while (socket!=null)
        {
            try {
                bytes=inputStream.read(buffer);
                if (bytes>0)
                {
                    handler.obtainMessage(MESSAGE_READ,bytes,-1,buffer).sendToTarget();
                }
            } catch (IOException e) {

                Log.d("error",e.getMessage());
            }
        }
    }


    public void write(byte[] bytes)
    {
        try {
            outputStream.write(bytes);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

}

I am getting this error on this part of code:-

  @Override
    public void run() {

        byte[] buffer=new byte[2048];
        int bytes;

        while (socket!=null)
        {
            try {
                bytes=inputStream.read(buffer);
                if (bytes>0)
                {
                    handler.obtainMessage(MESSAGE_READ,bytes,-1,buffer).sendToTarget();
                }
            } catch (IOException e) {

                Log.d("error",e.getMessage());
            }
        }
    }

Issue in Getting Peer List with the use of PeerListListener

I have to send a file using Wi-fi direct in my android application. I am using Wi-fi direct documentation to achive this.

So far I can discover peers. But, am geeting PeerList size 0.

I have done as below :

public class MyWifiActivity extends AppCompatActivity {

WifiP2pManager mManager;
WifiP2pManager.Channel mChannel;
BroadcastReceiver mReceiver;

IntentFilter mIntentFilter;

Button btnDisplayPeers;
private WifiP2pManager.PeerListListener myPeerListListener;

private List<WifiP2pDevice> mPeers;
private List<WifiP2pConfig> mConfigs;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_my_wifi);
    btnDisplayPeers = findViewById(R.id.displayPeers);
    myPeerListListener = new WifiP2pManager.PeerListListener() {
        @Override
        public void onPeersAvailable(WifiP2pDeviceList peers) {
            Toast.makeText(MyWifiActivity.this, "Peers Available", Toast.LENGTH_SHORT).show();
            displayPeers(peers);
        }
    };

    btnDisplayPeers.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if (mManager != null) {
                mManager.requestPeers(mChannel, myPeerListListener);
            }

        }
    });

    mManager = (WifiP2pManager) getSystemService(Context.WIFI_P2P_SERVICE);
    mChannel = mManager.initialize(this, getMainLooper(), null);
    mReceiver = new WiFiDirectBroadcastReceiver(mManager, mChannel, this);

    mIntentFilter = new IntentFilter();
    mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION);
    mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_PEERS_CHANGED_ACTION);
    mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION);
    mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_THIS_DEVICE_CHANGED_ACTION);


    mManager.discoverPeers(mChannel, new WifiP2pManager.ActionListener() {
        @Override
        public void onSuccess() {
            Toast.makeText(MyWifiActivity.this, "Discover Successful", Toast.LENGTH_SHORT).show();
        }

        @Override
        public void onFailure(int reasonCode) {
            Toast.makeText(MyWifiActivity.this, "Discover Failed.", Toast.LENGTH_SHORT).show();
        }
    });


    mPeers = new ArrayList<WifiP2pDevice>();
    mConfigs = new ArrayList<WifiP2pConfig>();

}

public void displayPeers(WifiP2pDeviceList peerList) {
    mPeers.clear();
    mPeers.addAll(peerList.getDeviceList());
    Toast.makeText(this, "Peer size "+peerList.getDeviceList().size(), Toast.LENGTH_SHORT).show();

    for (int i = 0; i < peerList.getDeviceList().size(); i++) {

        WifiP2pConfig config = null;
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
            config = new WifiP2pConfig();
        }
        config.deviceAddress = mPeers.get(i).deviceAddress;
        mConfigs.add(config);


    }

    for (int i = 0; i < mPeers.size(); i++) {
        Toast.makeText(this, "Peer : " + mPeers.get(i).toString(), Toast.LENGTH_SHORT).show();
    }

    for (int i = 0; i < mConfigs.size(); i++) {
        Toast.makeText(this, "Configs : " + mConfigs.get(i).toString(), Toast.LENGTH_SHORT).show();
    }

}


@Override
protected void onResume() {
    super.onResume();
    registerReceiver(mReceiver, mIntentFilter);
}

@Override
protected void onStop() {
    super.onStop();
    unregisterReceiver(mReceiver);
}
}

My BroadCast Receiver is as below :

public class WiFiDirectBroadcastReceiver extends BroadcastReceiver {
private WifiP2pManager mManager;
private WifiP2pManager.Channel mChannel;
private MyWifiActivity mActivity;

WifiP2pManager.PeerListListener myPeerListListener;


public WiFiDirectBroadcastReceiver(WifiP2pManager manager, WifiP2pManager.Channel channel,
                                   MyWifiActivity activity) {
    super();
    this.mManager = manager;
    this.mChannel = channel;
    this.mActivity = activity;
}

@Override
public void onReceive(Context context, Intent intent) {
    String action = intent.getAction();
    if (WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION.equals(action)) {
        // Check to see if Wi-Fi is enabled and notify appropriate activity
        int state = intent.getIntExtra(WifiP2pManager.EXTRA_WIFI_STATE, -1);
        if (state == WifiP2pManager.WIFI_P2P_STATE_ENABLED) {
            // Wifi P2P is enabled
            Toast.makeText(context, "P2P Enabled", Toast.LENGTH_SHORT).show();
        } else {
            // Wi-Fi P2P is not enabled
            Toast.makeText(context, "P2P Disabled", Toast.LENGTH_SHORT).show();
        }
    } else if (WifiP2pManager.WIFI_P2P_PEERS_CHANGED_ACTION.equals(action)) {
        // Call WifiP2pManager.requestPeers() to get a list of current peers
        // request available peers from the wifi p2p manager. This is an
        // asynchronous call and the calling activity is notified with a
        // callback on PeerListListener.onPeersAvailable()
        if (mManager != null) {
            mManager.requestPeers(mChannel, myPeerListListener);
        }




    } else if (WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION.equals(action)) {
        // Respond to new connection or disconnections
    } else if (WifiP2pManager.WIFI_P2P_THIS_DEVICE_CHANGED_ACTION.equals(action)) {
        // Respond to this device's wifi state changing
    }
}
}

I have also included permissions needed in Manifest file as below :

<uses-sdk android:minSdkVersion="14" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<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" />

Why am not getting Peer size 0 ? What might be the issue ? Thanks.

Wi-fi Direct : Getting Peer List size 0.

am working with Wi-fi p2p direct. I have successfully discover Peers. After the discovering the peers I have to display the Peer List in my listview.

But, Unfortunately getting peer size 0.

So far, I have done as below :

Below is my Simple Activity :

public class MyWifiActivity extends AppCompatActivity {

WifiP2pManager mManager;
WifiP2pManager.Channel mChannel;
BroadcastReceiver mReceiver;

IntentFilter mIntentFilter;

Button btnDisplayPeers;
private WifiP2pManager.PeerListListener myPeerListListener;

private List<WifiP2pDevice> mPeers;
private List<WifiP2pConfig> mConfigs;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_my_wifi);
    btnDisplayPeers = findViewById(R.id.displayPeers);
    myPeerListListener = new WifiP2pManager.PeerListListener() {
        @Override
        public void onPeersAvailable(WifiP2pDeviceList peers) {
            Toast.makeText(MyWifiActivity.this, "Peers Available", Toast.LENGTH_SHORT).show();
            displayPeers(peers);
        }
    };

    btnDisplayPeers.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if (mManager != null) {
                mManager.requestPeers(mChannel, myPeerListListener);
            }

        }
    });

    mManager = (WifiP2pManager) getSystemService(Context.WIFI_P2P_SERVICE);
    mChannel = mManager.initialize(this, getMainLooper(), null);
    mReceiver = new WiFiDirectBroadcastReceiver(mManager, mChannel, this);

    mIntentFilter = new IntentFilter();
    mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION);
    mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_PEERS_CHANGED_ACTION);
    mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION);
    mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_THIS_DEVICE_CHANGED_ACTION);


    mManager.discoverPeers(mChannel, new WifiP2pManager.ActionListener() {
        @Override
        public void onSuccess() {
            Toast.makeText(MyWifiActivity.this, "Discover Successful", Toast.LENGTH_SHORT).show();
        }

        @Override
        public void onFailure(int reasonCode) {
            Toast.makeText(MyWifiActivity.this, "Discover Failed.", Toast.LENGTH_SHORT).show();
        }
    });


    mPeers = new ArrayList<WifiP2pDevice>();
    mConfigs = new ArrayList<WifiP2pConfig>();

}

public void displayPeers(WifiP2pDeviceList peerList) {
    mPeers.clear();
    mPeers.addAll(peerList.getDeviceList());
    Toast.makeText(this, "Peer size "+peerList.getDeviceList().size(), Toast.LENGTH_SHORT).show();

    for (int i = 0; i < peerList.getDeviceList().size(); i++) {

        WifiP2pConfig config = null;
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
            config = new WifiP2pConfig();
        }
        config.deviceAddress = mPeers.get(i).deviceAddress;
        mConfigs.add(config);


    }

    for (int i = 0; i < mPeers.size(); i++) {
        Toast.makeText(this, "Peer : " + mPeers.get(i).toString(), Toast.LENGTH_SHORT).show();
    }

    for (int i = 0; i < mConfigs.size(); i++) {
        Toast.makeText(this, "Configs : " + mConfigs.get(i).toString(), Toast.LENGTH_SHORT).show();
    }

}


@Override
protected void onResume() {
    super.onResume();
    registerReceiver(mReceiver, mIntentFilter);
}

@Override
protected void onStop() {
    super.onStop();
    unregisterReceiver(mReceiver);
}

}

And Created BroadCard Receiver as below :

public class WiFiDirectBroadcastReceiver extends BroadcastReceiver {
    private WifiP2pManager mManager;
    private WifiP2pManager.Channel mChannel;
    private MyWifiActivity mActivity;

    WifiP2pManager.PeerListListener myPeerListListener;


    public WiFiDirectBroadcastReceiver(WifiP2pManager manager, WifiP2pManager.Channel channel,
                                       MyWifiActivity activity) {
        super();
        this.mManager = manager;
        this.mChannel = channel;
        this.mActivity = activity;
    }

    @Override
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        if (WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION.equals(action)) {
            // Check to see if Wi-Fi is enabled and notify appropriate activity
            int state = intent.getIntExtra(WifiP2pManager.EXTRA_WIFI_STATE, -1);
            if (state == WifiP2pManager.WIFI_P2P_STATE_ENABLED) {
                // Wifi P2P is enabled
                Toast.makeText(context, "P2P Enabled", Toast.LENGTH_SHORT).show();
            } else {
                // Wi-Fi P2P is not enabled
                Toast.makeText(context, "P2P Disabled", Toast.LENGTH_SHORT).show();
            }
        } else if (WifiP2pManager.WIFI_P2P_PEERS_CHANGED_ACTION.equals(action)) {
            // Call WifiP2pManager.requestPeers() to get a list of current peers
            // request available peers from the wifi p2p manager. This is an
            // asynchronous call and the calling activity is notified with a
            // callback on PeerListListener.onPeersAvailable()
            if (mManager != null) {
                mManager.requestPeers(mChannel, myPeerListListener);
            }




        } else if (WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION.equals(action)) {
            // Respond to new connection or disconnections
        } else if (WifiP2pManager.WIFI_P2P_THIS_DEVICE_CHANGED_ACTION.equals(action)) {
            // Respond to this device's wifi state changing
        }
    }
}

Permission is also set in Manifest :

<uses-sdk android:minSdkVersion="14" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<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" />

What might be the issue ? Pls. guide. Thanks.

How to change text size on Android Things?

I developed an application on AT_v0.3 developer version, Raspberry PI 3. The application on AT_v1.0 stable version size of text and other items are bigger and they are not visible.

Also, there is no option for sizes in the settings menu on AT_v1.0. So, is there a way to fix it without re-design the layouts?
Android device pingable but ADB shows offline
I'm running Android Things on a Raspberry Pi 3 which has been working well with ADB over WiFi and everything. Just recently I've encountered an issue where ADB initially can't connect to the device, but shows the device as connected [offline].
```
C:\WINDOWS\system32>adb connect 192.168.1.111
failed to connect to 192.168.1.111:5555
```
Then when I'm running adb connect again, I'm getting
```
C:\WINDOWS\system32>adb connect 192.168.1.111
already connected to 192.168.1.111:5555
```
The device list in ADB shows
```
C:\WINDOWS\system32>adb devices
List of devices attached
TA3640525I      device
192.168.1.5:5555        offline
```
Android Studio also treats the device as offline. Pinging works as;
```
C:\WINDOWS\system32>ping 192.168.1.5

Pinging 192.168.1.5 with 32 bytes of data:
Reply from 192.168.1.5: bytes=32 time=10ms TTL=64
Reply from 192.168.1.5: bytes=32 time=5ms TTL=64
Reply from 192.168.1.5: bytes=32 time=5ms TTL=64
Reply from 192.168.1.5: bytes=32 time=5ms TTL=64
```
Restarting the ADB daemon does not work either
```
C:\WINDOWS\system32>adb kill-server
```
I've not encountered this before, and it appeared all suddenly without any changes made to the system. I've tried to re-install ADB (ensuring that the SDK tools get removed), Android Studio and even device drivers. Any idea on what might have caused this?

Edit: I'm running Microsoft Windows 10 Enterprise Version 10.0.16299 Build 16299

Edit: Other computers on the network work very well without any issues.
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