Develop Reference

Android : How to Send a string over wi-fi without using printwriter?

The program here shows passing a string using wi-fi. I need a solution which does not require print writer or a simple solution which helps me send two different strings while toggling the buttons
switch3.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
if (switch3.isChecked()) {
messsage = "S";
Log.d("On", "Button On" + messsage);
new Thread(new Runnable() {
public void run() {
// TODO Auto-generated method stub
try {
// client = new
// Socket(etIP.getText().toString(), port);
client = new Socket("192.168.4.1", 100);
printwriter = new PrintWriter(client
.getOutputStream(), true);
printwriter.write(messsage);
printwriter.flush();
//printwriter.close();
client.close();
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}).start();
} else {
messsage = "T";
Log.d("off", "Button off " + messsage);// etMsg.getText().toString();
// etMsg.setText("");
// port = Integer.parseInt(etPort.getText().toString());
new Thread(new Runnable() {
public void run() {
// TODO Auto-generated method stub
try {
// client = new
// Socket(etIP.getText().toString(), port);
//client = new Socket("192.168.4.1", 100);
printwriter = new PrintWriter(client
.getOutputStream(), true);
printwriter.write(messsage);
printwriter.flush();
//printwriter.close();
client.close();
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}).start();
}
}
});

You can send data by this way ->
try {
Socket socket = new Socket(DESTINATION_ADDRESS, DESTINATION_PORT);
// Exmp : Socket socket = new Socket("192.168.0.101", 80);
OutputStream outToServer = socket.getOutputStream();
DataOutputStream out = new DataOutputStream(outToServer);
out.writeUTF(SEND_STRING);
// Exmp : out.writeUTF("TEST");
socket.close();
} catch (Exception e) {
e.printStackTrace();
}

Android Socket: Read Continuous Data

I am trying to read data continuously using the following code:
public class MyClientTask extends AsyncTask<Void, Void, Void> {
String dstAddress;
int dstPort;
String response = "";
MyClientTask(String addr, int port){
dstAddress = addr;
dstPort = port;
}
#Override
protected Void doInBackground(Void... arg0) {
Socket socket = null;
try {
socket = new Socket(dstAddress, dstPort);
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream(1024);
byte[] buffer = new byte[1024];
int bytesRead;
InputStream inputStream = socket.getInputStream();
while ((bytesRead = inputStream.read(buffer)) != -1){
readInpt = inputStream.toString();
byteArrayOutputStream.write(buffer, 0, bytesRead);
response = byteArrayOutputStream.toString("UTF-8");
}
textResponse.setText(readInpt);
} catch (UnknownHostException e) {
// TODO Auto-generated catch block
e.printStackTrace();
response = "UnknownHostException: " + e.toString();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
response = "IOException: " + e.toString();
}finally{
if(socket != null){
try {
socket.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
return null;
}
#Override
protected void onPostExecute(Void result) {
textResponse.setText(response);
super.onPostExecute(result);
}
}
But for some reason, it doesn't show me any output in the textbox. any help would be appreciated.

There are at least two issues in your code.
Frist, I'm not sure the method toString() on the inputStream is going to work, because the documentation says it returns a description of the object (which would be different than the string recieved). You might be confusing this with the contents of buffer which might be what you really want.
readInpt = inputStream.toString(); // Probably wrong
Second. You're updating the User Interface from a background thread, inside doInBackground() , which is always forbidden.
textResponse.setText(readInpt); // Forbidden, move somewhere else, e.g. onPostExecute()

try {
socket = new Socket(dstAddress, dstPort);
BufferedReader stdIn = new BufferedReader(new InputStreamReader(socket.getInputStream()));
while (true) {
response = stdIn.readLine();
publishProgress(response);
Log.i("response", response);
}
} catch (UnknownHostException e) {
// TODO Auto-generated catch block
e.printStackTrace();
response = "UnknownHostException: " + e.toString();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
response = "IOException: " + e.toString();
}
catch (Exception e) {
e.printStackTrace();
}
You cannot print it on text field because the socket will listen to the server socket.If server socket does not send any response it will listen to the socket continuously until the response is received.

data not sent using bluetooth socket (android)

I am trying to send a file using Android bluetooth sockets. I am getting the pairing requests but unfortunately the data is not being transferred
my Server side and client side is as follows:
Server: (for my application server is receiving the data)
public void run() {
super.run();
BluetoothAdapter mBtadapter = BluetoothAdapter.getDefaultAdapter();
Log.i("bluetooth Adapter", "got adapter "+ mBtadapter.getAddress());
try {
Ssocket = mBtadapter.listenUsingRfcommWithServiceRecord("CardXchange", uuid);
Log.i("Socket", "Socket Acquired "+ Ssocket.toString());
} catch (IOException e) {
e.printStackTrace();
}
while(true){
if(read_flag()==1){
try {
Toast.makeText(c, "flag is eventually 1", Toast.LENGTH_LONG).show();
Ssocket.close();
} catch (IOException e) {
e.printStackTrace();
}
break;
}
try {
client_socket = Ssocket.accept();
if(client_socket!=null){
//this function is used to handle the connection when sockets get connected
manageConnection1(client_socket);
Ssocket.close();
break;
}
} catch (IOException e) {
e.printStackTrace();
}
}
Log.i("breaked ", "oh god!! out of the loop ");
}
//implementation of the function
private void manageConnection1(BluetoothSocket client_socket2) {
// TODO Auto-generated method stub
int bytes;
Log.i("serevr chya manage connection madhe gela", "in servers manage connection ");
File file = new File("/sdcard/myfolder/received.Xcard");
try {
FileOutputStream fos = new FileOutputStream(file);
try {
InputStream is = client_socket2.getInputStream();
while((bytes = is.read(buffer, 0, 1024))>0){
fos.write(buffer, 0, 1024);
}
is.close();
fos.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} catch (FileNotFoundException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
try {
client_socket2.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
and the client side (the sending side is like this):
public void run(){
try {
Method m = send_dev.getClass().getMethod("createRfcommSocket", new Class[] {int.class});
Csocket = (BluetoothSocket) m.invoke(send_dev, 1);
Csocket.connect();
manageSendConnection(Csocket);
}catch(Exception e){
e.printStackTrace();
}
}
//function to handle after connection is established.
private void manageSendConnection(BluetoothSocket csocket) {
// TODO Auto-generated method stub
File f = new File("/sdcard/myfolder/card3.Xcard");
byte[] buffer = new byte[(int)f.length()];
try {
FileInputStream fis = new FileInputStream(f);
BufferedInputStream bis = new BufferedInputStream(fis);
try {
bis.read(buffer, 0, (int)f.length());
OutputStream os = csocket.getOutputStream();
os.write(buffer);
os.close();
fis.close();
bis.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} catch (FileNotFoundException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
try {
csocket.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
I am getting the pairing request but the data is not being sent.
can anyone please help me to find the problem and give a hint on solution??

Android How to read response of TCP client on port 502

I am developing an application to send a request to port 502 and want to read the response from the same port.
This is what i tried so far
public class Autoamtion extends Activity {
Socket echoSocket = null;
PrintWriter out = null;
BufferedReader in = null;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
.permitAll().build();
StrictMode.setThreadPolicy(policy);
Log.v("on create", "on create");
final ToggleButton fanOn = (ToggleButton) findViewById(R.id.toggleButton1);
fanOn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
if (fanOn.isChecked()) {
Toast.makeText(Autoamtion.this, "Fan is On",
Toast.LENGTH_SHORT).show();
Log.v("on create", "on create");
try {
echoSocket = new Socket("192.168.1.19", 502);
out = new PrintWriter(echoSocket.getOutputStream(),
true);
in = new BufferedReader(new InputStreamReader(
echoSocket.getInputStream()));
} catch (UnknownHostException e) {
System.err.println("Don't know about host: taranis.");
System.exit(1);
} catch (IOException e) {
System.err.println("Couldn't get I/O for "
+ "the connection to:192.168.1.19");
System.exit(1);
}
BufferedReader stdIn = new BufferedReader(
new InputStreamReader(System.in));
String userInput;
try {
while ((userInput = stdIn.readLine()) != null) {
out.println(userInput);
System.out.println("echo: " + in.readLine());
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
out.close();
try {
in.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
stdIn.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
echoSocket.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} else
Toast.makeText(Autoamtion.this, "Fan is Off",
Toast.LENGTH_SHORT).show();
}
});
}
}
i just installed one simulator which opens the port 502. i confirmed that port which gets open after running this simulator.
i just established the connection with 502 port. i am not getting any response from there.
Please guide me through this so i can make this working. Any advice and help would be appreciated .
Thanks

You should post stackTrace as well, to check what's failling.
At least one thing is not consistent in your information, your refer in the text port 503 and in your code you are using echoSocket = new Socket("192.168.1.19", 502); connecting to port 502.

android socket application, sockets send only the first time

I have an android client that listens to the smartphone's sensors and when it detects a variation in a sensor's value it produces a string (a "command"), and creates a socket and an output stream to send the string to a java server; every sensor listener creates a socket with a different port than the other listeners. I have also a "send" button and a textbox to send any other string to the server. The problem is that while the button "send" works fine and sends all the strings written in the textbox every time i press it, every listener sends the "command" only the first time they detect a variation in the sensors' values..
//listener buttonSend
Button.OnClickListener buttonSendOnClickListener = new Button.OnClickListener()
{
#Override
public void onClick(View arg0)
{
buttonSend.setEnabled(false);
Socket socket = null;
DataOutputStream dataOutputStream = null;
DataInputStream dataInputStream = null;
try
{
socket = new Socket(IP, 32450);
socket.setReuseAddress(true);
socket.setSoTimeout(2000);
dataOutputStream = new DataOutputStream(socket.getOutputStream());
dataInputStream = new DataInputStream(socket.getInputStream());
dataOutputStream.writeUTF(textOut.getText().toString());
textIn.setText(dataInputStream.readUTF());
}
catch (UnknownHostException e)
{
e.printStackTrace();
buttonSend.setEnabled(true);
}
catch (IOException e)
{
e.printStackTrace();
buttonSend.setEnabled(true);
}
finally
{
if (socket != null)
{
try
{
buttonSend.setEnabled(true);
socket.close();
}
catch (IOException e)
{
e.printStackTrace();
buttonSend.setEnabled(true);
}
}
if (dataOutputStream != null)
{
try
{
dataOutputStream.close();
}
catch (IOException e)
{
e.printStackTrace();
}
}
if (dataInputStream != null)
{
try
{
dataInputStream.close();
}
catch (IOException e)
{
e.printStackTrace();
}
}
}
}
}; //End listener buttonSend
this was the button and all the sensors work like this:
//proximity sensor event listener
SensorEventListener proximitySensorEventListener
= new SensorEventListener()
{
public void onAccuracyChanged(Sensor arg0, int arg1)
{
// TODO Auto-generated method stub
}
public void onSensorChanged(SensorEvent arg0)
{
// TODO Auto-generated method stub
if(arg0.sensor.getType()==Sensor.TYPE_PROXIMITY && IP!="")
{
textProximitySensorData.setText("Proximity Sensor Value:"
+ String.valueOf(arg0.values[0]));
String proxValue = "Proximity Sensor: VALUE "
+ String.valueOf(arg0.values[0]);
if(buttonSend.isEnabled()==true){
Socket socket = null;
DataOutputStream dataOutputStream = null;
try
{
socket = new Socket(IP, 32452);
socket.setReuseAddress(true);
socket.setSoTimeout(2000);
dataOutputStream = new DataOutputStream(socket.getOutputStream());
dataOutputStream.writeUTF(proxValue);
}
catch (UnknownHostException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
finally
{
if (socket != null)
{
try
{
socket.close();
socket=null;
}
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();
}
}
}
}
}
}
};
i tried setSoTimeout but it's useless because it's only for read, and setReuseAddress but it didn't work, logcat and console don't show any error when i run the application, can you help me finding the problem?