Develop Reference

Android InputStream reads garbage ServerSocket running in a Thread. How should ServerSocket read from client socket?

I have a an application which communicates between two android devices through socket. It seems like they do connect, but when data from the client socket is read by ServerSocket (using InputStream), it doesnot return the desired result (it is supposed to return somrthing like "21.24891706//95.23659845//ff8iuj67898n47fu" ).Instead I'm getting " [B#416b9488" as the message.
My client runs an AsyncTask and server runs a Thread.
Can you please help me solve this problem? Any help will is appreciated. Thanks in advance.
Here is Server.java which runs on the server:
import android.content.Context;
import android.widget.Toast;
import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintStream;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.NetworkInterface;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketException;
import java.util.Enumeration;
public class Server {
Context context;
ServerSocket serverSocket;
String message = "";
static final int socketServerPORT = 8080;
ShowConnectedStudents activity;
public Server(ShowConnectedStudents callingActivity) {
activity = callingActivity;
Thread socketServerThread = new Thread(new SocketServerThread());
socketServerThread.start();
}
public int getPort() {
return socketServerPORT;
}
public void onDestroy() {
if (serverSocket != null) {
try {
serverSocket.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
private class SocketServerThread extends Thread {
int count = 0;
byte buffer[] = new byte[1024];
int bytesRead;
String message;
#Override
public void run() {
try {
// create ServerSocket using specified port
serverSocket=new ServerSocket();
serverSocket.setReuseAddress(true);
serverSocket.bind(new InetSocketAddress(socketServerPORT));
while (true) {
// block the call until connection is created and return
// Socket object
Socket socket = serverSocket.accept();
message = "";
InputStream input = socket.getInputStream();
BufferedInputStream br= new BufferedInputStream(input);
while ((bytesRead = br.read(buffer)) != -1 ) {
message += " " + buffer.toString();
}
message += socket.isConnected();
message+=":"+socket.isClosed();
input.close();
activity.runOnUiThread(new Runnable() {
#Override
public void run() {
activity.status.setText("Message is: " + message);
}
});
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
Here is Client.java which runs on the client:
import android.os.AsyncTask;
import java.io.BufferedOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintStream;
import java.net.Socket;
import java.net.UnknownHostException;
public class Client extends AsyncTask<Void, Void, Void> {
String dstAddress;
int dstPort;
String status = "";
double Lat,Long;
String deviceId;
Socket socket = null;
ConnectToDevice activity;
byte buffer[] = new byte[1024];
int bytesRead;
Client(String addr, int port,double latitude,double longitude,String deviceIdentification,ConnectToDevice callingActivity) {
dstAddress = addr;
dstPort = port;
Lat=latitude;
Long=longitude;
deviceId=deviceIdentification;
activity=callingActivity;
if(dstAddress.charAt(0)=='/'){
dstAddress=dstAddress.substring(1);
}
}
#Override
protected Void doInBackground(Void... arg0) {
while(socket==null){
try {
socket = new Socket(dstAddress, dstPort);
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
try {
OutputStream outputStream = socket.getOutputStream();
PrintStream printStream = new PrintStream(outputStream,true);
printStream.print(Lat + "//" + Long+"//"+deviceId);
printStream.flush();
} catch (UnknownHostException e) {
e.printStackTrace();
status = "UnknownHostException: " + e.toString();
} catch (IOException e) {
e.printStackTrace();
status = "IOException: " + e.toString();
} finally {
}
return null;
}
#Override
protected void onPostExecute(Void result) {
activity.statusText.setText(Lat+ "//" + Long+"//"+deviceId);
super.onPostExecute(result);
}
}

toString() on a byte[] is not what you want, you're getting basically the memory address of the byte array
instead convert to a string, something like this
while ((bytesRead = br.read(buffer)) != -1 ) {
message += " " + new String(buffer, 0, bytesRead);
}

I have figured out another way, before reading this accepted answer. I'm posting it in case if it benefit anyone.
My data is text-only. So I wrapped the socket's input stream inside a Scanner.
InputStream input = socket.getInputStream();
Scanner scanner= new Scanner(input);
while(scanner.hasNextLine()){
message+=scanner.nextLine();
}

How do I receive bluetooth data from arduino to android?

I use a temperature sensor connected to arduino, then send temperature information through bluetooth to my phone. My phone application has a complete UI and is ready to receive information.
Every single tutorial I see is used to do the bluetooth pairing. I have not done this part yet (because arduino code is not complete yet, so can't test), but assuming I use the phone options to do the pairing, I still have no idea how to do the data transmission.
How do I receive information on the phone and display it? Could anyone point me to a tutorial or an explanation/code on how to proceed?
Thanks in advance!

Look at this.... very effective. In this code, you take a MAC address by file and connect it to the device automatically. Then you can send and receive string data from Arduino. You can take inspiration from this code.
import android.annotation.SuppressLint;
import android.annotation.TargetApi;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.ActivityInfo;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Build;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.view.WindowManager;
import android.view.animation.LinearInterpolator;
import android.webkit.WebView;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.ProgressBar;
import android.widget.Scroller;
import android.widget.SeekBar;
import android.widget.SeekBar.OnSeekBarChangeListener;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.ToggleButton;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.reflect.Method;
import java.util.UUID;
public class MainActivity extends Activity implements OnSeekBarChangeListener {
public String ultimodato;
////
private static final String TAG = "bluetooth2";
Handler h;
final int RECEIVE_MESSAGE = 1; //1 // Status for Handler
private BluetoothAdapter btAdapter = null;
private BluetoothSocket btSocket = null;
private StringBuilder sb = new StringBuilder();
private ConnectedThread mConnectedThread;
// SPP UUID service
private static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
// MAC-address of Bluetooth module (you must edit this line)
private static String address = "00:14:02:13:00:10";
////
#TargetApi(Build.VERSION_CODES.HONEYCOMB)
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
/* se non esiste il folder, creare il folder */
File folder = new File(Environment.getExternalStorageDirectory() + "/Asiagem");
boolean success = true;
if (!folder.exists()) {
success = folder.mkdir();
}
setContentView(R.layout.main);
//LETTURA DA FILE DEL MAC-ADDRESS A CUI CONNETTERSI
try{
String MACFile = readFileAsString("/sdcard/MAC.txt");
if(MACFile==""){
Toast.makeText(this,"Nessun dispositivo salvato, torno alla fase precedente", Toast.LENGTH_LONG).show();
Intent i = new Intent(getApplicationContext(), Home.class);
startActivity(i);
finish();
}else {
address = MACFile;
}
}catch(Exception e){
Toast.makeText(getApplicationContext(),"Errore nella lettura dei dati" , Toast.LENGTH_LONG).show();
Intent i = new Intent(getApplicationContext(), Home.class);
startActivity(i);
finish();
}
h = new Handler() {
public void handleMessage(android.os.Message msg) {
switch (msg.what) {
case RECEIVE_MESSAGE: // if receive massage
byte[] readBuf = (byte[]) msg.obj;
String strIncom = new String(readBuf, 0, msg.arg1); // create string from bytes array
Toast.makeText(getBaseContext(), strIncom, Toast.LENGTH_SHORT).show();
Log.d("INCOME", "INCOME: " + strIncom);
break;
}
};
};
btAdapter = BluetoothAdapter.getDefaultAdapter(); // get Bluetooth adapter
checkBTState();
}
private BluetoothSocket createBluetoothSocket(BluetoothDevice device) throws IOException {
if(Build.VERSION.SDK_INT >= 10){
try {
final Method m = device.getClass().getMethod("createInsecureRfcommSocketToServiceRecord", new Class[] { UUID.class });
return (BluetoothSocket) m.invoke(device, MY_UUID);
} catch (Exception e) {
Log.e(TAG, "Could not create Insecure RFComm Connection",e);
}
}
return device.createRfcommSocketToServiceRecord(MY_UUID);
}
#SuppressWarnings("deprecation")
#TargetApi(Build.VERSION_CODES.HONEYCOMB)
public void SendMessageBT(View v){
//INVIO MESSAGGIO AL BLUETOOTH
mConnectedThread.write("U");
}
#Override
public void onResume() {
super.onResume();
Log.d(TAG, "...onResume - try connect...");
// Set up a pointer to the remote node using it's address.
BluetoothDevice device = btAdapter.getRemoteDevice(address);
// Two things are needed to make a connection:
// A MAC address, which we got above.
// A Service ID or UUID. In this case we are using the
// UUID for SPP.
try {
btSocket = createBluetoothSocket(device);
} catch (IOException e) {
errorExit("Fatal Error", "In onResume() and socket create failed: " + e.getMessage() + ".");
}
// Discovery is resource intensive. Make sure it isn't going on
// when you attempt to connect and pass your message.
btAdapter.cancelDiscovery();
// Establish the connection. This will block until it connects.
Log.d(TAG, "...Connecting...");
try {
btSocket.connect();
Log.d(TAG, "....Connection ok...");
} catch (IOException e) {
try {
btSocket.close();
} catch (IOException e2) {
errorExit("Fatal Error", "In onResume() and unable to close socket during connection failure" + e2.getMessage() + ".");
}
}
// Create a data stream so we can talk to server.
Log.d(TAG, "...Create Socket...");
mConnectedThread = new ConnectedThread(btSocket);
mConnectedThread.start();
previousTime = System.currentTimeMillis();
}
#Override
public void onPause() {
super.onPause();
Log.d(TAG, "...In onPause()...");
try {
btSocket.close();
} catch (IOException e2) {
errorExit("Fatal Error", "In onPause() and failed to close socket." + e2.getMessage() + ".");
}
}
private void checkBTState() {
// Check for Bluetooth support and then check to make sure it is turned on
// Emulator doesn't support Bluetooth and will return null
if(btAdapter==null) {
errorExit("Fatal Error", "Bluetooth not support");
} else {
if (btAdapter.isEnabled()) {
Log.d(TAG, "...Bluetooth ON...");
} else {
//Prompt user to turn on Bluetooth
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, 1);
}
}
}
private void errorExit(String title, String message){
Toast.makeText(getBaseContext(), title + " - " + message, Toast.LENGTH_LONG).show();
finish();
}
private class ConnectedThread extends Thread {
private final InputStream mmInStream;
private final OutputStream mmOutStream;
public ConnectedThread(BluetoothSocket socket) {
InputStream tmpIn = null;
OutputStream tmpOut = null;
// Get the input and output streams, using temp objects because
// member streams are final
try {
tmpIn = socket.getInputStream();
tmpOut = socket.getOutputStream();
} catch (IOException e) { }
mmInStream = tmpIn;
mmOutStream = tmpOut;
}
public void run() {
byte[] buffer = new byte[256]; // buffer store for the stream
int bytes; // bytes returned from read()
// Keep listening to the InputStream until an exception occurs
while (true) {
if(System.currentTimeMillis() - previousTime > 10000){
previousTime = System.currentTimeMillis();
mConnectedThread.write("w");
}
try {
// Read from the InputStream
bytes = mmInStream.read(buffer); // Get number of bytes and message in "buffer"
h.obtainMessage(RECEIVE_MESSAGE, bytes, -1, buffer).sendToTarget(); // Send to message queue Handler
} catch (IOException e) {
break;
}
}
}
/* Call this from the main activity to send data to the remote device */
public void write(String message) {
Log.d(TAG, "...Data to send: " + message + "...");
byte[] msgBuffer = message.getBytes();
try {
mmOutStream.write(msgBuffer);
} catch (IOException e) {
Log.d(TAG, "...Error data send: " + e.getMessage() + "...");
ultimodato=message;
to_send=true;
//connect();
new connect_and_send().execute();
}
}
}
private class connect_and_send extends AsyncTask<Void, Void, Void> {
#Override
protected void onPreExecute() { // Fa vedere solo il dialog
super.onPreExecute();
}
#Override
protected Void doInBackground(Void... arg0) {
try {
btSocket.close();
Log.d(TAG, "...ALERT: " + "SOCKET CHIUSA" + "...");
} catch (IOException e2) {
errorExit("Fatal Error", "In onResume() and unable to close socket during connection failure" + e2.getMessage() + ".");
Log.d(TAG, "...ALERT: " + "IMPOSSIBILE CHIUDERE SOCKET" + "...");
}
Log.d(TAG, "...onResume - try connect...");
// Set up a pointer to the remote node using it's address.
BluetoothDevice device = btAdapter.getRemoteDevice(address);
// Two things are needed to make a connection:
// A MAC address, which we got above.
// A Service ID or UUID. In this case we are using the
// UUID for SPP.
try {
btSocket = createBluetoothSocket(device);
} catch (IOException e) {
errorExit("Fatal Error", "In onResume() and socket create failed: " + e.getMessage() + ".");
}
// Discovery is resource intensive. Make sure it isn't going on
// when you attempt to connect and pass your message.
btAdapter.cancelDiscovery();
// Establish the connection. This will block until it connects.
Log.d(TAG, "...Connecting...");
try {
btSocket.connect();
Log.d(TAG, "....Connection ok...");
} catch (IOException e) {
try {
btSocket.close();
} catch (IOException e2) {
errorExit("Fatal Error", "In onResume() and unable to close socket during connection failure" + e2.getMessage() + ".");
}
}
// Create a data stream so we can talk to server.
Log.d(TAG, "...Create Socket...");
mConnectedThread = new ConnectedThread(btSocket);
mConnectedThread.start();
//REINVIA L'ULTIMO DATO
if (to_send==true){
mConnectedThread.write(ultimodato);
to_send=false;
}
previousTime = System.currentTimeMillis();
return null;
}
#Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
}
}
public static String readFileAsString(String filePath) {
String result = "";
File file = new File(filePath);
if ( file.exists() ) {
FileInputStream fis = null;
try {
fis = new FileInputStream(file);
char current;
while (fis.available() > 0) {
current = (char) fis.read();
result = result + String.valueOf(current);
}
} catch (Exception e) {
Log.d("TourGuide", e.toString());
} finally {
if (fis != null)
try {
fis.close();
} catch (IOException ignored) {
}
}
}
return result;
}
}

Unable to read data (send by server) at Client Side

I am trying to develop an app in which
1.client sends request to server for connection(IP address+PORT no.)+sends data using "PrintStream"+Tries to read the data from Server(Using Inputstream)
2.Client creates the socket.
3.Server reads the data send by Client
4.SERVER writes the data using "PrintStream" at same time point no 3.
Problem is at point 4 Data written by SERVER is not Read by "INPUTSTREAM" of client(Point 1)
I dont know these Simultaneous operation are possible or not.If possible then how.If not then what is the alternate way?
Server Code
package com.example.loneranger.ser;
import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketException;
import java.util.Enumeration;
public class MainActivity extends Activity {
TextView ip;
TextView msg;
String data = "";
ServerSocket httpServerSocket;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ip = (TextView) findViewById(R.id.infoip);
msg = (TextView) findViewById(R.id.msg);
ip.setText(getIpAddress() + ":"
+ 8080 + "\n");
Server server = new Server();
server.start();
}
#Override
protected void onDestroy() {
super.onDestroy();
if (httpServerSocket != null) {
try {
httpServerSocket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
private String getIpAddress() {
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 += "IP: "
+ inetAddress.getHostAddress() + "\n";
}
}
}
} catch (SocketException e) {
// TODO Auto-generated catch block
e.printStackTrace();
ip += "Something Wrong! " + e.toString() + "\n";
}
return ip;
}
private class Server extends Thread {
#Override
public void run() {
Socket socket = null;
try {
httpServerSocket = new ServerSocket(8888);
while(true){
socket = httpServerSocket.accept();
HttpResponseThread httpResponseThread =
new HttpResponseThread(
socket);
httpResponseThread.start();
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
private class HttpResponseThread extends Thread {
Socket socket;
HttpResponseThread(Socket socket){
this.socket = socket;
}
#Override
public void run() {
BufferedReader BReader;
PrintWriter printer;
String request;
try { InputStream inputStream = socket.getInputStream();
BReader = new BufferedReader(new InputStreamReader(inputStream));
request = BReader.readLine();
Thread.sleep(500);
printer = new PrintWriter(socket.getOutputStream(), true);
printer.print("hello laundu");
printer.flush();
String ip123=socket.getInetAddress().toString();
printer.close();
BReader.close();
socket.close();
data += "Request of " + request
+ " from "+ ip123 + "\n";
MainActivity.this.runOnUiThread(new Runnable() {
#Override
public void run() {
msg.setText(data);
}
});
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
}
return;
}
}
}
Client Code
mport android.os.AsyncTask;
import android.widget.TextView;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.net.Socket;
import java.net.UnknownHostException;
public class Client extends AsyncTask<Void, Void, Void> {
String dstAddress;
int dstPort;
String response = "";
TextView textResponse;
MainActivity activity;
OutputStream outputStream;
BufferedReader BReader;
String request;
Client(String addr, int port, TextView textResponse) {
dstAddress = addr;
dstPort = port;
this.textResponse=textResponse;
this.activity=activity;
}
#Override
protected Void doInBackground(Void... arg0) {
Socket socket = null;
try {
socket = new Socket(dstAddress, dstPort);
Server server = new Server(socket);
server.start();
PrintWriter out = new PrintWriter(new BufferedWriter(
new OutputStreamWriter(socket.getOutputStream())),
true);
out.print("futfujb");
out.flush();
/*
* notice: inputStream.read() will block if no data return
*/
} 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 {
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}*/
return null;
}
#Override
protected void onPostExecute(Void result) {
textResponse.setText(response);
super.onPostExecute(result);
}
private class Server extends Thread {
Socket socket;
Server(Socket socket)
{
this.socket=socket;
}
#Override
public void run() {
try { //Thread.sleep(500);
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream(
1024);
byte[] buffer = new byte[1024];
int bytesRead;
InputStream inputStream = socket.getInputStream();
if(inputStream.available()>0)
{
while ((bytesRead = inputStream.read(buffer)) != -1) {
byteArrayOutputStream.write(buffer, 0, bytesRead);
response += byteArrayOutputStream.toString("UTF-8");
}
}
inputStream.close();
socket.close();
}
catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}

As I commented above, there is nothing in this code that corresponds to either of these steps:
2.Server gets the request creates new SOCKET connection.
(a) There is no request, and (b) the server does not create a new connection. The client creates it. The server accepts it.
3.Server reads the data send by Client.
The client doesn't send any data.
There are two problems here (at least):
The server is blocking in readLine() waiting for a message that the client never sends. So it never gets to its own send, so nothing is received by the client. Have the client send a request, as per the comments.
The client is incorrectly using available(). Remove this test and let the client fall through into the read loop. It will exit that when the peer (the server) closes the connection.

Android run code in Service all the time

I want to create a Service that runs in the background and checks if the client sends a message to the server and answers to it.
Here's what I tried so far:
package com.server.test;
import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.widget.Toast;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.ServerSocket;
import java.net.Socket;
public class ServerService extends Service {
private static ServerSocket serverSocket;
private static Socket clientSocket;
private static InputStreamReader inputStreamReader;
private static BufferedReader bufferedReader;
private static String message;
Thread serverThread;
#Override
public IBinder onBind(Intent intent) {
return null;
}
#Override
public void onCreate() {
System.out.println("hello1");
Toast.makeText(this, "Server Started", Toast.LENGTH_LONG).show();
serverThread = new Thread(new Runnable() {
public void run() {
try {
System.out.println("hello2");
try {
serverSocket = new ServerSocket(4444);
} catch (IOException e) {
System.out.println("Could not listen on port: 4444");
}
System.out.println("Server started. Listening to the port 4444");
while (true) {
System.out.println("hello3");
try {
clientSocket = serverSocket.accept();
inputStreamReader = new InputStreamReader(clientSocket.getInputStream());
bufferedReader = new BufferedReader(inputStreamReader);
message = bufferedReader.readLine();
System.out.println(message);
inputStreamReader.close();
clientSocket.close();
} catch (IOException ex) {
System.out.println("Problem in message reading");
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
});
serverThread.start();
}
}
The problem is, that when the code is in onCreate(), it only gets executed when the service gets created, and I want it to run all the time. So where do I have to put the code in the Service class so it runs all the time?
Best Regards,
Alex

Android Client-server message exchanging is slow

I have a working messaging app that sends messages from the client to the server.
I want the client to CONSTANTLY listen for messages from the server.
I want the client to only send packets to the server when "Start" is called, but the problem is that I have to press it twice for the message to actually deliver to the server (Idk why)
Later on I'll change the program to something that always delivers messages to the server (his GPS location), so I would also like some tips about how to make a loop in an Android app.
//Client
package com.example.clienttest;
import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.Socket;
import android.os.Bundle;
import android.app.Activity;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivity extends Activity {
Thread m_objThreadClient;
Socket clientSocket;
TextView serverMessage;
EditText clientMessage;
String sIn, sOut;
BufferedReader brOut, brIn;
DataOutputStream oos;
DataInputStream ois;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
serverMessage = (TextView) findViewById(R.id.textView1);
clientMessage = (EditText) findViewById(R.id.editText1);
m_objThreadClient = new Thread( new Runnable(){
public void run()
{
try {
clientSocket = new Socket("192.168.1.102", 4000);
oos = new DataOutputStream (clientSocket.getOutputStream());
ois = new DataInputStream (clientSocket.getInputStream());
brIn = new BufferedReader (new InputStreamReader(ois));
} catch (IOException e) {
serverMessage.setText(e.getMessage());
}
}
});
m_objThreadClient.start();
}
public void Listener(){
try {
while ((sIn = brIn.readLine()) != null){
sIn = brIn.readLine();
}
serverMessage.setText(sIn);
} catch (IOException e) {
serverMessage.setText(e.getMessage());
}
}
public void Start(View view) {
sOut = clientMessage.getText().toString();
try {
oos.writeUTF(sOut);
oos.flush();
oos.flush();
} catch (IOException e) {
serverMessage.setText(e.getMessage());
}
}
public void onStop(){
try {
oos.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
//Server
import java.net.ServerSocket;
import java.net.Socket;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.PrintWriter;
import java.util.Hashtable;
public class Server2 {
#SuppressWarnings("resource")
public static void main (String[] args) throws IOException {
ServerSocket server = null;
try {
server = new ServerSocket(4000);
} catch (IOException e) {
System.err.println("Could not start up on: " + "4000" + "Maby server is already open? Or a portforwording messup?");
System.err.println(e);
System.exit(1);
}
Socket client = null;
while(true) {
try {
client = server.accept();
System.out.print("Connected ");
} catch (IOException e) {
System.err.println("Accept failed.");
System.err.println(e);
}
Thread t = new Thread(new ClientConn(client));
t.start();
}
}
}
class ClientConn implements Runnable {
private Socket client;
String Recv;
DataInputStream inFromClient;
DataOutputStream outToClient;
ClientConn(Socket client) {
this.client = client;
try {
inFromClient = new DataInputStream(client.getInputStream());
outToClient = new DataOutputStream(client.getOutputStream());
} catch (IOException e) {
e.printStackTrace();
}
}
public void run() {
String response;
try {
while ((response = inFromClient.readUTF()) != null) {
Recv = inFromClient.readUTF();
System.out.print("Msg: " + Recv + " \n");
if( Recv.equals("Hi")){
outToClient.writeUTF("Wa alaikum");
outToClient.flush();
}
else{
outToClient.writeUTF("..what?");
outToClient.flush();
}
}
} catch (IOException e) {
System.out.print("No input ");
System.err.println(e);
}
}
}