Server Ip at Client side using Sockets - java

I need to create an application using android socket level programming, I created a connection between server and client but I need to show waiting server IP list at client side and select one IP from the list and establish a connection between them.
Here is my code for server side
public class Server extends AppCompatActivity {
private static final String TAG = "ServerActivity";
private TextView tvServerStatus;
private TextView recievemsg;
InetAddress receiverAddress;
public static String SERVERIP = "";
DatagramSocket datagramSocket;
public static final int SERVERPORT = 8080;
private Handler handler = new Handler();
Handler updateConversationHandler;
private ServerSocket serverSocket;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_server);
updateConversationHandler = new Handler();
tvServerStatus = (TextView) findViewById(R.id.tvServerStatus);
recievemsg=(TextView)findViewById(R.id.send_msg);
SERVERIP = getLocalIpAddress();
Thread fst = new Thread(new ServerThread());
fst.start();
try {
datagramSocket = new DatagramSocket(8080);
byte[] buffer = "0123456789".getBytes();
byte[] address=SERVERIP.getBytes();
receiverAddress = InetAddress.getByAddress(address);
DatagramPacket packet = new DatagramPacket(
buffer, buffer.length, receiverAddress, 8080);
datagramSocket.send(packet);
} catch (SocketException e) {
e.printStackTrace();
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
private String getLocalIpAddress() {
String ip = "";
try {
Enumeration<NetworkInterface> enumNetworkInterfaces = NetworkInterface
.getNetworkInterfaces();
while (enumNetworkInterfaces.hasMoreElements()) {
NetworkInterface networkInterface = enumNetworkInterfaces
.nextElement();
Enumeration<InetAddress> enumInetAddress = networkInterface
.getInetAddresses();
while (enumInetAddress.hasMoreElements()) {
InetAddress inetAddress = enumInetAddress.nextElement();
if (inetAddress.isSiteLocalAddress()) {
ip += "SiteLocalAddress: "
+ inetAddress.getHostAddress() + "\n";
}
}
}
} catch (SocketException e) {
// TODO Auto-generated catch block
e.printStackTrace();
ip += "Something Wrong! " + e.toString() + "\n";
}
return ip;
}
public class ServerThread implements Runnable {
#Override
public void run() {
try {
Log.e(TAG, "Server IP: " + SERVERIP);
if (SERVERIP != null) {
handler.post(new Runnable() {
#Override
public void run() {
tvServerStatus.setText("Listening On Ip: " + SERVERIP);
}
});
serverSocket = new ServerSocket(SERVERPORT);
while (!Thread.currentThread().isInterrupted()) {
{
try {
// LISTEN FOR INCOMING CLIENTS
Socket client = serverSocket.accept();
CommunicationThread commThread = new CommunicationThread(client);
new Thread(commThread).start();
// Log.e(TAG, "Client Socket: " + client);
// new Clients_Handle(client, ROOT_DIRECTORY).start();
}
catch (IOException e) {
e.printStackTrace();
}
}
}
} else {
handler.post(new Runnable() {
#Override
public void run() {
tvServerStatus.setText("Couldn't detect internet connection.");
}
});
}
} catch (IOException e) {
handler.post(new Runnable() {
#Override
public void run() {
tvServerStatus.setText("Error");
}
});
e.printStackTrace();
}
}
}
class CommunicationThread implements Runnable {
private Socket clientSocket;
private BufferedReader input;
public CommunicationThread(Socket clientSocket) {
this.clientSocket = clientSocket;
try {
this.input = new BufferedReader(new InputStreamReader(this.clientSocket.getInputStream()));
} catch (IOException e) {
e.printStackTrace();
}
}
public void run() {
while (!Thread.currentThread().isInterrupted()) {
try {
String read = input.readLine();
updateConversationHandler.post(new updateUIThread(read));
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
class updateUIThread implements Runnable {
private String msg;
public updateUIThread(String str) {
this.msg = str;
}
#Override
public void run() {
recievemsg.setText(recievemsg.getText().toString() + "Client Says: " + msg + "\n");
}
}
#Override
protected void onDestroy() {
super.onDestroy();
try {
// MAKE SURE YOU CLOSE THE SOCKET UPON EXITING
serverSocket.close();
Log.e(TAG,"Socket Closed");
} catch (IOException e) {
e.printStackTrace();
}
}
}
And here is my client side code
public class Clientss extends AppCompatActivity {
private static final String TAG = "Client_Activity";
private EditText etServerIp;
private EditText etMsg;
private Button btnConnectClients;
private Button btnSendMsg;
private TextView textIn;
private String serverIpAddress = "";
private String t;
private boolean connected = false;
DatagramSocket datagramSocket;
DatagramPacket packet;
private Socket socket;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_clientss);
Log.e(TAG, "ONCREATE METHOD");
textIn = (TextView)findViewById(R.id.txt_msg);
initializations();
eventClickListener();
try {
datagramSocket = new DatagramSocket(8080);
byte[] buffer = new byte[10];
packet = new DatagramPacket(buffer, buffer.length);
datagramSocket.receive(packet);
byte[] buff = packet.getData();
textIn.setText(buff.toString());
System.out.println("this is incoming ip"+buff.toString());
} catch (SocketException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
// textIn.setText(t);
}
private void eventClickListener() {
btnConnectClients.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (!connected) {
serverIpAddress = etServerIp.getText().toString().trim();
connectsClient();
}
}
});
btnSendMsg.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String msg = etMsg.getText().toString().trim();
ClientResponseTask clientResponseTask=new ClientResponseTask(msg);
clientResponseTask.execute();
}
});
}
private void connectsClient() {
if (!serverIpAddress.equals("")) {
Thread cThread = new Thread(new ClientThread());
cThread.start();
}
}
private void initializations() {
etServerIp = (EditText) findViewById(R.id.etServerIp);
etMsg = (EditText) findViewById(R.id.etMsg);
btnSendMsg = (Button) findViewById(R.id.btnMsgSend);
btnConnectClients = (Button) findViewById(R.id.btnConnect);
}
private class ClientThread implements Runnable {
#Override
public void run() {
try {
InetAddress serverAddr = InetAddress.getByName(serverIpAddress);
Log.e(TAG, "C: Connecting...");
socket = new Socket(serverAddr, Server.SERVERPORT);
System.out.println("this is socket"+socket);
connected = true;
Message msg = handler.obtainMessage();
msg.arg1 = 1;
handler.sendMessage(msg);
//showToast("");
Log.e(TAG, "C: Connected..." + socket);
} catch (Exception e) {
Log.e(TAG, "C: Error", e);
connected = false;
}
}
}
private final Handler handler = new Handler() {
public void handleMessage(Message msg) {
if(msg.arg1 == 1)
Toast.makeText(getApplicationContext(),"Connected...", Toast.LENGTH_LONG).show();
}
};
#Override
protected void onDestroy() {
if (socket != null) try {
socket.close();
Log.e(TAG, "C: Socket Closed.");
} catch (IOException e) {
e.printStackTrace();
} finally
{
try
{
socket.close();
}
catch(Exception e){}
}
super.onDestroy();
}
protected class ClientResponseTask extends AsyncTask<Void,Void,Void> {
String msg;
ClientResponseTask(String msg){
this.msg=msg;
}
#Override
protected Void doInBackground(Void... params) {
if (connected) {
try {
PrintWriter out = new PrintWriter(new BufferedWriter(
new OutputStreamWriter(socket.getOutputStream())), true);
out.println(msg);
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (Exception e) {
Log.e(TAG, "Error", e);
}
}
else {
connectsClient();
}
return null;
}
}
}
Please help me to find a solution.

Related

ObjectOutputStream throwing Exception

I'm trying to write a simple client/server program, where the client is an android app and the server is a Raspberry Pi 4. All I want to do is allow the client to type a message and have the Raspberry Pi display the message on the terminal. However, my app keeps throwing an exception at the out.writeObject(message_text) line in the sendMessage() method.
public class MainActivity extends AppCompatActivity {
private EditText message;
private Button send;
private ObjectOutputStream out;
private Socket socket;
private String raspi_ip = "enter ip here";
private int raspi_portnum = 12345;
Client client;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
message = findViewById(R.id.message_text);
send = findViewById(R.id.send_button);
try{
client = new Client(raspi_ip,raspi_portnum);
client.start();
} catch (Exception e){
AlertDialog.Builder dialog = new AlertDialog.Builder(MainActivity.this);
dialog.setTitle("Error! ").setMessage("Couldn't connect to server.").setNeutralButton("OK", null).create().show();
}
send.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
client.sendMessage();
}
});
}
private void closeConnection(){
try{
out.close();
socket.close();
} catch (Exception e){
e.printStackTrace();
}
}
#Override
protected void onStop(){
super.onStop();
closeConnection();
}
private class Client extends Thread {
private String ip_address;
private int port_number;
public Client(String ipaddress,int portnum){
this.ip_address = ipaddress;
this.port_number = portnum;
}
#Override
public void run() {
super.run();
connectToServer(ip_address,port_number);
}
public void connectToServer(String ipaddress, int portnum){
try{
socket = new Socket(InetAddress.getByName(ipaddress),portnum);
out = new ObjectOutputStream(socket.getOutputStream());
out.flush();
}catch (Exception e){
AlertDialog.Builder dialog = new AlertDialog.Builder(MainActivity.this);
dialog.setTitle("Error! ").setMessage("Couldn't connect to server.").setNeutralButton("OK", null).create().show();
}
}
public void sendMessage(){
String message_text = message.getText().toString();
try{
out.writeObject(message_text);
out.flush();
} catch (Exception e) {
AlertDialog.Builder dialog = new AlertDialog.Builder(MainActivity.this);
dialog.setTitle("Error! ").setMessage("IO Exception.").setNeutralButton("OK", null).create().show();
}
}
}
}
Here is the server side java program:
import java.io.ObjectInputStream;
import java.net.ServerSocket;
import java.net.Socket;
public class RaspPiServer {
private ServerSocket server;
public RaspPiServer(){
}
public static void main(String[] args){
RaspPiServer server = new RaspPiServer();
server.runServer();
}
public void runServer(){
try{
server = new ServerSocket(12345,100);
while (true){
new Controller(server.accept()).start();
}
} catch(Exception e){
e.printStackTrace();
}
}
private class Controller extends Thread {
private Socket socket;
private ObjectInputStream input;
private String in;
public Controller(Socket socket){
this.socket = socket;
System.out.println("New client at " + socket.getRemoteSocketAddress());
}
#Override
public void run(){
try{
input = new ObjectInputStream(socket.getInputStream());
while (!(in = (String)input.readObject()).equals("close")){
System.out.println(in);
}
} catch(Exception e){
e.printStackTrace();
} finally {
closeConnection();
System.out.println("Connection with client # " + socket.getRemoteSocketAddress() + " closed");
}
}
private void closeConnection() {
try {
input.close();
socket.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
Is there an easy fix here, or am I missing something bigger?

Android Sockets not working in reality

I am trying to connect an Android device to a java server. It works perfectly when I use the emulator but when I port it onto my phone there is no connection.
The aim of the code is to send a value from client to server, perform a calculation on it and return it back to the client to be displayed.
This is my server code:
public class ServerTest {
public static final int PORT_NUMBER = 8000;
protected Socket socket;
private ServerTest(Socket socket) {
this.socket = socket;
System.out.println("New client connected from " + socket.getInetAddress().getHostAddress());
connect();
}
public void connect() {
InputStream in = null;
OutputStream out = null;
try {
in = socket.getInputStream();
out = socket.getOutputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(in));
String request = br.readLine();
if (request.equals("end")) {
System.out.println("Message received: " + request + ". Ending connection.");
request = "End Connection";
out.write(request.getBytes());
in.close();
out.close();
socket.close();
System.exit(0);
} else {
System.out.println("Message received: " + request);
request = calculatePi(request);
System.out.println("Output: " + request);
out.write(request.getBytes());
}
} catch (IOException ex) {
System.out.println("Unable to get streams from client");
} finally {
try {
in.close();
out.close();
socket.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
public static void main(String[] args) {
System.out.println("Welcome. IP address is: " + getIP());
ServerSocket server = null;
try {
server = new ServerSocket(PORT_NUMBER);
while (true) {
new ServerTest(server.accept());
}
} catch (IOException ex) {
System.out.println("Unable to start server.");
} finally {
try {
if (server != null)
server.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
private static String getIP() {
String ip = "";
try {
Enumeration<NetworkInterface> interfaces = NetworkInterface.getNetworkInterfaces();
while (interfaces.hasMoreElements()) {
NetworkInterface iface = interfaces.nextElement();
// filters out 127.0.0.1 and inactive interfaces
if (iface.isLoopback() || !iface.isUp())
continue;
Enumeration<InetAddress> addresses = iface.getInetAddresses();
while(addresses.hasMoreElements()) {
InetAddress addr = addresses.nextElement();
// *EDIT*
if (addr instanceof Inet6Address) continue;
ip = addr.getHostAddress();
}
}
} catch (SocketException e) {
throw new RuntimeException(e);
}
return ip;
}
and this is my client side code on device:
public class MainActivity extends AppCompatActivity {
TextView piResultTextView;
EditText addressEditText, messageEditText;
Button connectButton;
Handler handler = new Handler();
Results results;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
results = new Results();
addressEditText = findViewById(R.id.AddressEditText);
messageEditText = findViewById(R.id.MessageEditText);
connectButton = findViewById(R.id.ConnectButton);
connectButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
connect();
}
});
piResultTextView = findViewById(R.id.PiResultTextView);
}
public void connect() {
Thread thread = new Thread(new Runnable() {
#Override
public void run() {
String hostAddress = addressEditText.getText().toString();
int port = 8000;
Socket echoSocket = null;
PrintWriter out = null;
BufferedReader in = null;
try {
echoSocket = new Socket(hostAddress, port);
out = new PrintWriter(echoSocket.getOutputStream(), true);
in = new BufferedReader(new InputStreamReader(echoSocket.getInputStream()));
} catch (UnknownHostException e) {
Toast.makeText(getApplicationContext(), "Unknown host: " + hostAddress, Toast.LENGTH_SHORT).show();
} catch (IOException e) {
Toast.makeText(getApplicationContext(), "Unable to get streams from server", Toast.LENGTH_SHORT).show();
}
String input = messageEditText.getText().toString();
try {
out.println(input);
results.pi = in.readLine();
handler.post(new Runnable() {
#Override
public void run() {
piResultTextView.setText(results.pi);
}
});
} catch (IOException e) {
Toast.makeText(getApplicationContext(), "Unable to read input stream from server", Toast.LENGTH_SHORT).show();
}
try {
out.close();
in.close();
echoSocket.close();
} catch (IOException e) {
Toast.makeText(getApplicationContext(), "Error closing streams", Toast.LENGTH_SHORT).show();
}
}
});
thread.start();
}
}

Sockets - Simple C# Server and JAVA Android Client

I'm trying for sometime now and I cant figure it out why this is not working.
CLIENT:
public class MainActivity extends AppCompatActivity {
private Socket socket;
public static final int PORT = 6000;
public static final String server_IP = "192.168.2.30";
public String mensagem = null;
public String mensagem_final = null;
Button btn_conetar;
TextView txt;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btn_conetar = (Button) findViewById(R.id.btn_conetar);
txt = (TextView) findViewById(R.id.txt);
Thread t = new Thread() {
public void run() {
try {
while(!isInterrupted())
{
Thread.sleep(1000);
runOnUiThread(new Runnable() {
#Override
public void run() {
txt.setText(mensagem_final);
}
});
}
} catch (InterruptedException e) {
e.printStackTrace();
}
}
};
t.start();
}
public void onClick(View view)
{
new Thread((new ClientThread())).start();
//Intent i = new Intent(MainActivity.this,Main2Activity.class);
// startActivity(i);
}
//Thread que inicia o socket
class ClientThread implements Runnable
{
#Override
public void run() {
try
{
InetAddress serveradress = InetAddress.getByName(server_IP);
Log.e("TCP","A conetar...");
socket = new Socket(serveradress,PORT);
BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
while((mensagem = in.readLine()) != null)
{
mensagem_final += mensagem;
}
if(in.readLine() == null)
{
Log.e("TCP","Nao tem mensagens");
}
Log.e("MSG",mensagem);
socket.close();
}
catch (UnknownHostException e)
{
e.printStackTrace();
} catch (IOException e)
{
e.printStackTrace();
}
}
}
}
Server:
Servidor servidor = new Servidor();
servidor.serverthread();
class Servidor
{
public void serverthread()
{
Thread serverthread = new Thread(server);
serverthread.Start();
}
public void server()
{
Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
TcpListener tcplistener = new TcpListener(IPAddress.Any, 6000);
tcplistener.Start();
TcpClient tcpclient = tcplistener.AcceptTcpClient();
byte[] data = new byte[1024];
NetworkStream ns = tcpclient.GetStream();
string welcome = "Ola";
data = Encoding.ASCII.GetBytes(welcome);
ns.Write(data, 0, data.Length);
}
}
Any idea why I cant receive the string "Ola" in my android application? It doesnt give me any error, it just doesnt do anything.
My internet's default adress is 192.168.2.1.
Good links are also welcome.

How can I check by a button click which ip to connect?

On the MainActivity.java I have a method that connect with a server:
private byte[] Get(String urlIn)
{
URL url = null;
String urlStr = urlIn;
if (urlIn!=null)
urlStr=urlIn;
try
{
url = new URL(urlStr);
} catch (MalformedURLException e)
{
e.printStackTrace();
return null;
}
HttpURLConnection urlConnection = null;
try
{
urlConnection = (HttpURLConnection) url.openConnection();
InputStream in = new BufferedInputStream(urlConnection.getInputStream());
byte[] buf=new byte[10*1024];
int szRead = in.read(buf);
byte[] bufOut;
if (szRead==10*1024)
{
throw new AndroidRuntimeException("the returned data is bigger than 10*1024.. we don't handle it..");
}
else
{
bufOut = Arrays.copyOf(buf, szRead);
}
return bufOut;
}
catch (IOException e)
{
e.printStackTrace();
return null;
}
finally
{
if (urlConnection!=null)
urlConnection.disconnect();
}
}
I'm calling this method from onTouchEvent():
#Override
public boolean onTouchEvent(MotionEvent event)
{
float eventX = event.getX();
float eventY = event.getY();
float lastdownx = 0;
float lastdowny = 0;
switch (event.getAction())
{
case MotionEvent.ACTION_DOWN:
path.moveTo(eventX, eventY);
circlePath.addCircle(eventX, eventY, 50, Path.Direction.CW);
lastdownx = eventX;
lastdowny = eventY;
Thread t = new Thread(new Runnable()
{
#Override
public void run()
{
byte[] response = null;
if (is_start == true)
{
response = Get("http://10.0.0.2:8098/?cmd=start");
is_start = false;
}
else
{
response = Get("http://10.0.0.2:8098/?cmd=stop");
is_start = true;
}
if (response!=null)
{
String a = null;
try
{
a = new String(response,"UTF-8");
textforthespeacch = a;
MainActivity.currentActivity.initTTS();
} catch (UnsupportedEncodingException e)
{
e.printStackTrace();
}
Logger.getLogger("MainActivity(inside thread)").info(a);
}
}
});
t.start();
return true;
case MotionEvent.ACTION_MOVE:
path.lineTo(eventX, eventY);
break;
case MotionEvent.ACTION_UP:
circlePath.reset();
break;
default:
return false;
}
invalidate();
return true;
}
So now i'm connecting all the time to 10.0.0.2:8098
But that's when i connect my android device on my network on my pc room.
But if i move to the living room and connect to the network there a differenet network with another pc the pc ip is differenet in this case: 10.0.0.3:8099
So i added a button click event to the MainActivity.java:
public class MainActivity extends ActionBarActivity
{
private static final int MY_DATA_CHECK_CODE = 0;
public static MainActivity currentActivity;
TextToSpeech mTts;
private String targetURL;
private String urlParameters;
private Button btnClick;
private String clicking = "clicked";
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
addListenerOnButton();
currentActivity = this;
initTTS();
}
public void addListenerOnButton() {
btnClick = (Button) findViewById(R.id.checkipbutton);
btnClick.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View arg0)
{
}
});
}
Inside the button click event I want to check after connected to the network with a wifi if the pc ip is 10.0.0.3:8099 or 10.0.0.2:8098
I need that it will try to connect to this servers and if success then to set to a global variable global string the ip.
I added a global variable: string ipaddress
Now i use static address in my code but i need to check which ip address is correct and then to set this ip to the variable which i will use later in my code as the ip address.
How do I make the checking in the button click event ?
This is what i tried now:
At the top of my MainActivity i added:
private final String[] ipaddresses = new String[2];
private final Integer[] ipports = new Integer[2];
Socket socket = null;
Then in the onCreate:
ipaddresses[0] = "10.0.0.3";
ipaddresses[1] = "10.0.0.2";
ipports[0] = 8098;
ipports[1] = 8088;
addListenerOnButton();
new Thread(new ClientThread()).start();
Then
public void addListenerOnButton() {
btnClick = (Button) findViewById(R.id.checkipbutton);
btnClick.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View arg0)
{
try {
String str = btnClick.getText().toString();
PrintWriter out = new PrintWriter(new BufferedWriter(
new OutputStreamWriter(socket.getOutputStream())),
true);
out.println(str);
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
And the ClientThread
class ClientThread implements Runnable {
#Override
public void run() {
for (int i=0; i<ipaddresses.length; i++)
{
try
{
InetAddress serverAddr = InetAddress.getByName(ipaddresses[i]);
socket = new Socket(serverAddr, ipports[i]);
} catch (UnknownHostException e1)
{
e1.printStackTrace();
} catch (IOException e1)
{
e1.printStackTrace();
}
}
}
}
This is a screenshot of the exception message i'm getting:
The exception is on the line:
new OutputStreamWriter(socket.getOutputStream())),
You must open sockets to check server connectivity. Here is an example on you send strings to server on click event:
public class Client extends Activity {
private Socket socket;
private static final int SERVERPORT = 8099;
private static final String SERVER_IP = "10.0.0.3";
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
new Thread(new ClientThread()).start();
}
public void onClick(View view) {
try {
EditText et = (EditText) findViewById(R.id.EditText01);
String str = et.getText().toString();
PrintWriter out = new PrintWriter(new BufferedWriter(
new OutputStreamWriter(socket.getOutputStream())),
true);
out.println(str);
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
}
class ClientThread implements Runnable {
#Override
public void run() {
try {
InetAddress serverAddr = InetAddress.getByName(SERVER_IP);
socket = new Socket(serverAddr, SERVERPORT);
} catch (UnknownHostException e1) {
e1.printStackTrace();
} catch (IOException e1) {
e1.printStackTrace();
}
}
}
}
So if you get an exception trying to connect to server, it means you haven't connectivity.

Unable to establish socket connect between two different android devices at different locations with different service providers

I am trying to establish a socket connection between two different devices at different places. I am using Airtel SIM on my android device. I am running following code on the device:
public class MainActivity extends Activity
{
Context context;
TextView info, infoip, msg;
String message = "";
ServerSocket serverSocket;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
context = this;
Sql s = new Sql(context);
info = (TextView) findViewById(R.id.info);
infoip = (TextView) findViewById(R.id.infoip);
msg = (TextView) findViewById(R.id.msg);
new GetPublicIPTask().execute();
}
private class SocketServerThread extends Thread
{
static final int SocketServerPORT = 8080;
int count = 0;
#Override
public void run()
{
try
{
serverSocket = new ServerSocket(SocketServerPORT);
MainActivity.this.runOnUiThread(new Runnable()
{
#Override
public void run()
{
info.setText("Port: " + serverSocket.getLocalPort());
}
});
while (true)
{
Socket socket = null;
try
{
socket = serverSocket.accept();
}
catch (Exception e)
{
e.printStackTrace();
}
count++;
message += "#" + count + " from " + socket.getInetAddress() + ":" + socket.getPort() + "\n";
MainActivity.this.runOnUiThread(new Runnable()
{
#Override
public void run()
{
msg.setText(message);
}
});
SocketServerReplyThread socketServerReplyThread = new SocketServerReplyThread(socket, count);
socketServerReplyThread.run();
}
}
catch (IOException e)
{
e.printStackTrace();
}
}
}
private class SocketServerReplyThread extends Thread
{
private Socket hostThreadSocket;
int cnt;
SocketServerReplyThread(Socket socket, int c)
{
hostThreadSocket = socket;
cnt = c;
}
#Override
public void run()
{
OutputStream outputStream;
String msgReply = "Hello client " + cnt;
try
{
outputStream = hostThreadSocket.getOutputStream();
PrintStream printStream = new PrintStream(outputStream);
printStream.print(msgReply);
printStream.close();
message += "replied: " + msgReply + "\n";
MainActivity.this.runOnUiThread(new Runnable()
{
#Override
public void run()
{
msg.setText(message);
}
});
}
catch (IOException e)
{
e.printStackTrace();
message += "Exception! " + e.toString() + "\n";
}
MainActivity.this.runOnUiThread(new Runnable()
{
#Override
public void run()
{
msg.setText(message);
}
});
}
}
public class GetPublicIPTask extends AsyncTask<String, Integer, String>
{
ProgressDialog progressDialog;
String serverResponse = "";
public GetPublicIPTask()
{
progressDialog = new ProgressDialog(context);
}
#Override
protected void onPreExecute()
{
if (!NetWorkInfo.isOnline(context))
{
Toast.makeText(context, "No Internet Connection", Toast.LENGTH_LONG).show();
return;
}
progressDialog.setMessage("Getting IP");
progressDialog.setCancelable(false);
progressDialog.show();
}
#Override
protected String doInBackground(String... sUrl)
{
BufferedReader in = null;
int TIME_OUT = 1000 * 60 * 10;
HttpClient httpclient = new DefaultHttpClient();
HttpParams params = httpclient.getParams();
HttpConnectionParams.setConnectionTimeout(params, TIME_OUT);
HttpConnectionParams.setSoTimeout(params, TIME_OUT);
HttpGet httppost = new HttpGet("http://checkip.dyndns.org");
httppost.setHeader("Content-Type", "application/json");
try
{
HttpResponse response = httpclient.execute(httppost);
in = new BufferedReader(new InputStreamReader(response.getEntity().getContent(), "UTF-8"));
StringBuffer sb = new StringBuffer("");
String line = "";
while ((line = in.readLine()) != null)
{
sb.append(line);
}
serverResponse = sb.toString();
return serverResponse;
}
catch (Exception ex)
{
Log.d("Socket Server", "StackTrace : " + ex.getStackTrace().toString());
}
finally
{
try
{
if (in != null)
{
in.close();
}
}
catch (IOException e)
{
throw new RuntimeException(e);
}
}
return null;
}
#Override
protected void onPostExecute(String result)
{
if (progressDialog != null && progressDialog.isShowing())
{
progressDialog.dismiss();
}
infoip.setText(serverResponse);
Thread socketServerThread = new Thread(new SocketServerThread());
socketServerThread.start();
super.onPostExecute(result);
}
}
}
And from terminal I am hitting the mobile app:
telnet publicIpAddress 8080
Same process working in local network, but not working in mobile networks.

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