I am trying to create a 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 a 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()); } } }