Apps Two android clients & one java server

[GaryDoo]

Hi,

I'm hoping someone can help me, I've created a java server and an android client (A), the client(A) gets it's GPS coordinates and sends them to the server, I need the server to send them to client(B). I'm not entirely sure as to what to do, whether I should have separate ports etc or what.

Below is my two clients and server


SERVER

[HIGH]import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.iutputStream;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;

public class TCPServer {

public static void main(String[] args) throws Exception {

Socket socketChild;
Socket socketParent;

ServerSocket ServerSocketChild = new ServerSocket(5555);
ServerSocket ServerSocketParent = new ServerSocket(6666);


System.out.println("Server started. Listening to the port 2001");
System.out.println("Server: waiting for connection ..");

while (true) {
try {
socketChild = ServerSocketChild.accept();
socketParent = ServerSocketParent.accept();

if (socketChild != null) {

InputStream fromChild = socketChild.getInputStream();

while (socketChild.isConnected() && socketParent.isConnected()) {

System.out.println("Child Connected");
System.out.println("Parent Connected");

Scanner r = new Scanner(fromChild);
String location;
location = r.nextLine();
System.out.println(location);

OutputStream out = socketParent.getOutputStream();
PrintWriter toParent = new PrintWriter(out);
toParent.print(location);

toParent.close();
}
}


} catch (IOException ex) {
System.out.println("Problem in message reading");
}
}
}
}
[/HIGH]

CLIENT A


[HIGH]import java.io.DataOutputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.net.Socket;
import java.net.UnknownHostException;
import android.app.Activity;
import android.content.Context;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.util.Log;
import android.widget.Toast;


public class Child extends Activity implements LocationListener {

private Socket s;
private PrintWriter p;
public static double latitude;
public static double longitude;
String coordinates;


@Override
public void onCreate(Bundle savedInstanceState)

{
super.onCreate(savedInstanceState);
setContentView(R.layout.child);

LocationManager mlocationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
LocationListener mlocationListener = new MyLocationListener();

mlocationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0,
mlocationListener);

String hello = "hello"; //FOR TESTING PURPOSES

Transmit (hello);

Log.d("test", "test");
}



public class MyLocationListener implements LocationListener {

public void onProviderDisabled(String provider) {
Toast.makeText(getApplicationContext(), "Gps Disabled",
Toast.LENGTH_SHORT).show();
}

public void onProviderEnabled(String provider) {
Toast.makeText(getApplicationContext(), "Gps Enabled",
Toast.LENGTH_SHORT).show();
}
public void onStatusChanged(String provider, int status, Bundle extras) {

}

public void onLocationChanged(Location location) {
// TODO Auto-generated method stub
latitude = location.getLatitude();
longitude = location.getLongitude();

coordinates = ("TESTING " + latitude + longitude);

//Transmit(coordinates);
}
}

private void Transmit(final String message) {

Thread trans = new Thread(new Runnable() {

public void run() {

Log.d("TRANSMIT", "CALLED");

// TODO Auto-generated method stub
try {

s = new Socket("192.168.3.101", 5555); // connect to
// server
Log.d("CONNECTED", "Connected");

DataOutputStream _OutPut = new DataOutputStream(
s.getOutputStream());
_OutPut.writeBytes(message + "\n");
_OutPut.flush();
_OutPut.close();

} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
});
trans.start();
}

public void onLocationChanged(Location location) {
// TODO Auto-generated method stub

}

public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub

}

public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub

}

public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub

}


}[/HIGH]

CLIENT B

[HIGH]import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.iutputStream;
import java.io.PrintWriter;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.Scanner;

import android.app.Activity;
import android.content.Context;
//import android.location.LocationListener;
//import android.location.LocationManager;
import android.os.Bundle;
import android.util.Log;
import android.widget.EditText;
import android.widget.TextView;

public class Parent extends Activity {

private Socket s;
private PrintWriter p;
String location;

public void onCreate(Bundle savedInstanceState)

{
super.onCreate(savedInstanceState);
setContentView(R.layout.parent);

Thread rec = new Thread(new Runnable() {

public void run() {

//Log.d("TRANSMIT", "CALLED");

// TODO Auto-generated method stub
try {

s = new Socket("192.168.3.101", 6666); // connect to
// server
InputStream fromServer = s.getInputStream();
//Log.d("CONNECTED", "Connected");

while (s.isConnected()) {

Scanner r = new Scanner(fromServer);
location = r.nextLine();

//OutputStream out = s.getOutputStream();
//PrintWriter p = new PrintWriter(out);

}

} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
});
rec.start();

TextView myTextview = (TextView) findViewById(R.id.dist);
myTextview.setText(location);
}
}[/HIGH]

With this, I run the server, then run CLIENT B in the emulator and CLIENT A on the device, once I run CLIENT A, CLIENT B force shuts.

CLIENT A / SERVER connectivity is 100%, it prints to console (for testing). What I need to try to find out is how do I send the data to CLIENT B, I have used different ports and i'm sure that's why CLIENT B force shuts. I'm only learning Android a few months and I'm teaching myself, so any help would be greatly appreciated.

Regards,
Gary

 

[dlhavema]

what exception gets thrown in Client B? Have you used LogCat before? Its a nice debugging console for Android. Also look into using the Log class for debugging, then you can step through the code ( kinda like system.out.println() statements ) to see where its stopping.