Develop Reference

connecting to socket over wifi - android

I am trying to use sockets in Android to connect over wifi to some UDP port (some_port) on a machine in my local network whose ip is some_ip.
When I run
socket = new Socket(some_ip, some_port);
I get no message error but the program does not seem to read this line and I can't log the error when surrounding with try/catch.
How can I debug that ?
Edit 1 : here's my try/catch
try{
socket = new Socket(some_ip, some_port);
}
catch(ConnectException e) {
e.printStackTrace();
}
Edit 2 : here's the entire code
private void getUDPData() throws IOException {
class ProcessUPDTask extends AsyncTask<String, Void, Socket> {
private Exception exception;
private Socket socket;
public ProcessUPDTask() throws IOException {
}
private void runThread(){
new Thread() {
public void run() {
Toast.makeText(activity, "Own Message", Toast.LENGTH_LONG).show();
}
}.start();
}
protected Socket doInBackground(String... urls) {
try {
try{
socket = new Socket(some_ip, some_port);
socket.setSoTimeout(1500);
}
catch(IOException e) {
e.printStackTrace();
}
Log.d("TAG","this line is reached");
while(true){
try {
dataInputStream = new DataInputStream(socket.getInputStream());
dataOutputStream = new DataOutputStream(socket.getOutputStream());
System.out.println("ip: " + socket.getInetAddress());
System.out.println("message: " + dataInputStream.readUTF());
dataOutputStream.writeUTF("Hello!");
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
finally{
if( socket!= null){
try {
socket.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if( dataInputStream!= null){
try {
dataInputStream.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if( dataOutputStream!= null){
try {
dataOutputStream.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
} catch (Exception e) {
this.exception = e;
e.printStackTrace();
return null;
}
}
protected void onPostExecute(Socket socket) {
// TODO: check this.exception
// TODO: do something with the feed
}
}
new ProcessUPDTask().execute();
}

Try this
try {
Socket socket = new Socket(IP_ADDRESS, PORT);
socket.setSoTimeout(1500);
} catch (IOException ex) {
Log.e("Connection Error",String.valueOf(ex));
}
Replace your code with this and wait some seconds(60 sec for now) you can see the error toast..
private void getUDPData() throws IOException {
class ProcessUPDTask extends AsyncTask<String, Void, Socket> {
private Exception exception;
private Socket socket;
public ProcessUPDTask() throws IOException {
}
protected Socket doInBackground(String... urls) {
try {
try {
socket = new Socket("192.168.1.101", 1234);
socket.setSoTimeout(1500);
} catch (IOException e) {
runOnUiThread(new Runnable() {
#Override
public void run() {
Toast.makeText(MainActivity.this, "Error", Toast.LENGTH_LONG).show();
}
});
}
runOnUiThread(new Runnable() {
#Override
public void run() {
Toast.makeText(MainActivity.this, "Reached", Toast.LENGTH_LONG).show();
}
});
while (true) {
try {
dataInputStream = new DataInputStream(socket.getInputStream());
dataOutputStream = new DataOutputStream(socket.getOutputStream());
System.out.println("ip: " + socket.getInetAddress());
System.out.println("message: " + dataInputStream.readUTF());
dataOutputStream.writeUTF("Hello!");
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
if (socket != null) {
try {
socket.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if (dataInputStream != null) {
try {
dataInputStream.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if (dataOutputStream != null) {
try {
dataOutputStream.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
} catch (Exception e) {
this.exception = e;
e.printStackTrace();
return null;
}
}
protected void onPostExecute(Socket socket) {
// TODO: check this.exception
// TODO: do something with the feed
}
}
new ProcessUPDTask().execute();
}

You can configure this and use transData() between connectivity.
private void transData(int sending_msg_int) throws IOException {
String sending_msg = Integer.toString(sending_msg_int);
SocketAddress socketAddress = new InetSocketAddress(ip, Data.Port);
DatagramSocket ds = new DatagramSocket();
byte[] buffer = sending_msg.getBytes();
DatagramPacket dp = new DatagramPacket(buffer, buffer.length,
socketAddress);
ds.send(dp);
ds.close();
}

Second connection to Bluetooth device fails in Android

I'm trying to establish a Bluetooth connection in Android 4.4 but the connect method of BluetoothSocket seems to be working strangely. My app can assume the device is already bonded, so I can connect via MAC address. The thing is that it connects perfectly and immediately the first time the device is bonded, but if I relaunch it, the connection isn't established and a timeout occurs. I do this inside a while loop until it connects, but it takes too long for a real solution or it doesn't work at all. Here's a sample of my code:
public class BluetoothManager{
private BluetoothAdapter bluetoothAdapter;
private BluetoothDevice bluetoothDevice;
private BluetoothSocket socket;
private OutputStream output;
private InputStream input;
public BluetoothManager() {
/***************/
/* Constructor */
/***************/
// lock = new Object();
bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
}
public boolean turnOnBluetooth() {
/**************************************/
/* Turn on Bluetooth an notify result */
/**************************************/
// check if bluetooth is supported
if (bluetoothAdapter == null) {
return (false);
} else {
// enable Bluetooth if not enabled yet
if (!bluetoothAdapter.isEnabled()) {
bluetoothAdapter.enable();
}
while (!bluetoothAdapter.isEnabled()) {
Log.i("Debug", "Waiting for bluetooth to turn on");
try {
Thread.sleep(500);
} catch (Exception e) {
}
}
return (true);
}
}
public boolean turnOffBluetooth() {
/***************************************/
/* Turn off Bluetooth an notify result */
/***************************************/
// check if bluetooth is supported
if (bluetoothAdapter == null) {
return (false);
} else {
// disable Bluetooth if not enabled yet
if (bluetoothAdapter.isEnabled()) {
bluetoothAdapter.disable();
}
while (bluetoothAdapter.isEnabled()) {
Log.i("Debug
Thread.sleep(500);
} catch (Exception e) {
}
}
return (true);
}
}
public boolean configureBluetooth(String MACaddress) {
/***********************************************************************/
/* Configures to the specified bluetooth device and returns the result */
/***********************************************************************/
Log.i("Debug", "Connecting to Bluetooth Device");
bluetoothDevice = bluetoothAdapter.getRemoteDevice(MACaddress);
return (true);
}
#SuppressLint("NewApi")
public void createSocket() throws NoSuchMethodException, IllegalAccessException, IllegalArgumentException, InvocationTargetException{
final UUID serialUUID = UUID
.fromString("00001101-0000-1000-8000-00805F9B34FB");
socket = null;
output = null;
input = null;
Method m = bluetoothDevice.getClass().getMethod("createInsecureRfcommSocket", new Class[] { int.class });
socket = (BluetoothSocket)m.invoke(bluetoothDevice, 1);
}
#SuppressLint("NewApi")
public void connect() throws IOException, NoSuchMethodException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
/************************************/
/* Connects to the bluetooth device */
/************************************/
Log.i("Debug", "en connect");
while (!socket.isConnected()) { // we try until the connection is established
try {
socket.connect();
output = socket.getOutputStream();
input = socket.getInputStream();
} catch (IOException e) {
Log.i("Depuración", "Connection not established. Another run : "+e);
try {
Thread.sleep(1000);
} catch (Exception e1) {
}
}
}
}
public void terminateConnection() throws IOException {
Log.i("Debug", "terminating connection");
if(output!=null){
Log.i("Debug", "output!=null - stop streaming");
stopStreaming();
}
try {
Thread.sleep(100);
} catch (Exception e) {
}
if(input!=null){
Log.i("Debug", "input!=null");
input.close();
input=null;
}
if(output!=null){
Log.i("Depuración", "output!=null");
output.close();
output = null;
}
if(socket!=null){
Log.i("Debug", "socket!=null");
socket.close();
socket=null;
}
try {
Thread.sleep(100);
} catch (Exception e) {
}
turnOffBluetooth();
try {
Thread.sleep(100);
} catch (Exception e) {
}
try {
Thread.sleep(100);
} catch (Exception e) {
}
System.gc();
}
If I call this methods from my MainActivity, it works, but only the first time the device is bonded. If I launch the app again I get an exception trying to connect to the device in:
socket.connect();
I suspect it has something to do with the way I terminate the connection, but I can't figure it out. Here's the sequential call of the methods:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
bluetoothManager = new BluetoothManager();
try {
bluetoothManager.terminateConnection();
} catch (IOException e2) {
// TODO Auto-generated catch block
e2.printStackTrace();
}
bluetoothManager.turnOffBluetooth();
bluetoothManager.turnOnBluetooth();
boolean configured = false;
while (!configured) {
Log.i("Debug", "Configuration Attemp");
configured = bluetoothManager.configureBluetooth(MACaddress);
}
Log.i("Debug", "Bluetooth Configured");
try {
bluetoothManager.createSocket();
} catch (NoSuchMethodException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (IllegalAccessException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (IllegalArgumentException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (InvocationTargetException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
Log.i("Depuración", "Socket created");
try {
bluetoothManager.connect();
} catch (IOException e) {
e.printStackTrace();
} catch (NoSuchMethodException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalArgumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvocationTargetException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Log.i("Debug", "Connected!!!!");
protected void onPause() {
Log.i("Debug", "On pause");
// TODO Auto-generated method stub
try {
bluetoothManager.terminateConnection();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
bluetoothManager = null;
System.gc();
super.onPause();
};
I've been trying to solve this for days and I still can't find a reason.

Well I'm not a Pro on this, but it looks like you should call bluetoothManager.terminateConnection(); when app is closing, lets say onDestroy, but not onCreate; I also had problems to connect, if previous connection was not terminated correctly. just try add this method to your main activity:
#Override
public void onDestroy(){
if (bluetoothManager != null){
bluetoothManager.terminateConnection();
}
super.onDestroy();
}
hope that helps.

messed up with publishProgress method while using it in AsyncTask

I am trying to implement simple internal data storage code.In it I want to show ProgressDialog for some background process which will increment by 5 while calling publishProgress(). But it gives me error like the following,
The method publishProgress(R.integer...) in the type AsyncTask<String,R.integer,String> is not applicable for the arguments (int)
following is the code.
public class loadSomeStuff extends AsyncTask<String, integer, String>
{
ProgressDialog dailog;
protected void onPreExecute()
{
//example of setting up something
dailog=new ProgressDialog(MainActivity.this);
dailog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
dailog.setMax(100);
dailog.show();
}
#Override
protected String doInBackground(String... params) {
// TODO Auto-generated method stub
String collected=null;
FileInputStream fis=null;
for(int i=1; i<=20; i++)
{
publishProgress(5);
try {
Thread.sleep(100);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
dailog.dismiss();
try {
fis=openFileInput(FileName);
byte[] dataArray = new byte[fis.available()];
while(fis.read(dataArray)!= -1)
{
collected=new String(dataArray);
}
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
try {
fis.close();
return collected;
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return null;
}
protected void onProgressUpdate(Integer...progress)
{
dailog.incrementProgressBy(5);
}
protected void onPostExecute(String result)
{
DataResults.setText(result);
}
}

Generics cannot use value types so your AsyncTask needs to use Integer:
extends AsyncTask<String, Integer, String>

try this :
extends AsyncTask<String, Integer, String>
Integer with a capital I

I have tried your code on my machine and its working fine without any error.
You can check now with my code.
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
loadSomeStuff objSomeStuff = new loadSomeStuff();
objSomeStuff.execute();
}
public class loadSomeStuff extends AsyncTask<String, Integer, String>
{
ProgressDialog dailog;
protected void onPreExecute()
{
//example of setting up something
dailog=new ProgressDialog(MainActivity.this);
dailog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
dailog.setMax(100);
dailog.show();
}
#Override
protected String doInBackground(String... params) {
// TODO Auto-generated method stub
String collected=null;
FileInputStream fis=null;
for(int i=1; i<=20; i++)
{
publishProgress(5);
try {
Thread.sleep(100);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
dailog.dismiss();
try {
fis=openFileInput("");
byte[] dataArray = new byte[fis.available()];
while(fis.read(dataArray)!= -1)
{
collected=new String(dataArray);
}
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
try {
fis.close();
return collected;
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return null;
}
protected void onProgressUpdate(Integer...progress)
{
dailog.incrementProgressBy(5);
}
protected void onPostExecute(String result)
{
//DataResults.setText(result);
Toast.makeText(getApplicationContext(), "", Toast.LENGTH_LONG).show();
}
}
}

Alright I think you may have messed up with some namespaces. Here is what you need to do
Organize your imports Ctrl+Shift+O. make sure there is no invalid import. it may have happned if you copy & paste code from any other source.
Clean your project.
AsyncTask should look like this:
public class LoadSomeStuff extends AsyncTask<String, Integer, String>
Let me know if you still cant resolve it .

simple answer is that
in the Question Code Mention is
AsyncTask< String, integer, String>
But change that for progress updated
AsyncTask< String, Integer, String>
if use AsyncTask**< String, String, String>** then should be Cast into Interger for
progress update.

TCP in Android - ObjectOutputStream writeObject failure

I'm trying to send an Object from my phone to my PC(Windows) using a TCP socket via WiFi. When I try the same code between two PCs, it works without any error. But when I put the client code to the android device, it fails to send date using writeObject method. But writeUTF command works. It gives the "Software caused connection abort: recv failed" error. Below is the Code. Please help..
Server(in PC):
public class Test {
public static void main(String arg[]) {
ServerSocket serverSocket = null;
Socket socket = null;
ObjectInputStream in = null;
ObjectOutputStream out = null;
try {
serverSocket = new ServerSocket(8888);
System.out.println("Listening :8888");
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
while (true) {
try {
socket = serverSocket.accept();
in = new ObjectInputStream(socket.getInputStream());
out = new ObjectOutputStream(socket.getOutputStream());
out.flush();
System.out.println("ip: " + socket.getInetAddress());
Message msg = (Message) in.readObject(); //Message captured from chat client.
System.out.println(msg.type + " message received from " + msg.sender + " Containing " + msg.content);
out.writeObject(new Message("Ack", "Server", "Message Received", "Client"));
out.flush();
} catch (IOException e) {
e.printStackTrace();
} catch (ClassNotFoundException ex) {
Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);
}
finally {
if (socket != null) {
try {
socket.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if (in != null) {
try {
in.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if (out != null) {
try {
out.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
}
}
Client (in Android Device):
public class MainActivity extends Activity{
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button bb=(Button)findViewById(R.id.button1);
bb.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
new Send().execute();
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
private class Send extends AsyncTask<Void, Void, Void> {
Socket socket = null;
ObjectOutputStream out = null;
ObjectInputStream in = null;
protected Void doInBackground(Void... arg0) {
try {
socket = new Socket("192.168.43.92", 8888); //use the IP address of the server
out = new ObjectOutputStream(socket.getOutputStream());
out.flush();
out.writeObject(new Message("Chat", "Server", "Hello World", "Server")); //This method is used to write something to the server.
out.flush();
Message msg = (Message) in.readObject();
System.out.println(msg.type + " message received from " + msg.sender + " Containing " + msg.content);
} catch (UnknownHostException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
finally {
if (socket != null) {
try {
socket.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if (out != null) {
try {
out.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if (in != null) {
try {
in.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
return null;
}
protected void onProgressUpdate(Integer... progress) {
//setProgressPercent(progress[0]);
}
protected void onPostExecute(Long result) {
//showDialog("Downloaded " + result + " bytes");
}
}
}
Message(in Both Sides):
public class Message implements Serializable{
private static final long serialVersionUID = 1L;
public String type, sender, content, recipient;
public Message(String type, String sender, String content, String recipient){
this.type = type; this.sender = sender; this.content = content; this.recipient = recipient;
}
#Override
public String toString(){
return "{type='"+type+"', sender='"+sender+"', content='"+content+"', recipient='"+recipient+"'}";
}
}

Is the network between the client and server setup properly via your WiFi? Download one of those ping & telnet test apps and use it to test your network connection.
Telnet is a useful TCP debugging app. If you have a server listening on 11.22.33.44 port 1234, you should be able to telnet 11.22.33.44 1234

Maybe, you need to add this functions into Message class:
private void writeObject(java.io.ObjectOutputStream stream)
throws IOException {
stream.writeObject(type);
stream.writeObject(sender);
stream.writeObject(content);
stream.writeObject(recipient);
}
private void readObject(java.io.ObjectInputStream stream)
throws IOException, ClassNotFoundException {
type = (String) stream.readObject();
sender = (String) stream.readObject();
content = (String) stream.readObject();
recipient = (String) stream.readObject();
}
http://developer.android.com/reference/java/io/Serializable.html

How to get the new data update from a json url in android?

I am working in an online radio streaming project. I play the stream from a url and parsing the sound track info from another json url. All that I did is I repeatedly parse the json after every 10 seconds thats why when the sound track is changing I can get the track info of that specific track. But the json file is being updated 30+ sec before the track changes, thats why sometimes there is a noticeable dissimilarity between the track and the track info.
Here is my asyncTask class where I am playing the stream.
public class RadioPlayer extends AsyncTask<String, Void, Void> {
MediaPlayer mediaPlayer = new MediaPlayer();
#Override
protected void onPreExecute() {
}
#Override
protected Void doInBackground(String... params) {
mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
try {
mediaPlayer.setDataSource(params[0]);
mediaPlayer.prepare();
} catch (IllegalArgumentException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (SecurityException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (IllegalStateException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
// might take long! (for buffering, etc)
mediaPlayer.start();
return null;
}
#Override
protected void onPostExecute(Void result) {
}
and here is the handler where I am updating the track info after every 10 seconds:
private void getSongStatistics() {
r = new Runnable() {
public void run() {
try {
title = tsp.parseInitiator();
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
Log.i("title", title);
try {
String[] subTitles = title.split("-");
tvTitle.setText(subTitles[1]);
tvArtist.setText(subTitles[0]);
} catch (Exception e) {
tvArtist.setText(title);
}
handler.postDelayed(this, 10000);
}
}
};
handler.postDelayed(r, 10000);
}
Is there any solution by which I may get rid of this weird problem?

Use push instead of polling to update data.