Both client and server windows are blank - sockets

Question

I am trying to test player position communication between a client and a server. I am doing this by building a game environment where the other player's position is also displayed. They connect properly, but both the windows are blank white. If I terminate one program only then the other displays the playground. Also in the action listener which listens for the timer only sends the data and doesn't proceed. Can I get help for displaying the windows properly and fixing the action listener?
Here is the client code :
public class SamplePlayerClient1
{
private static JFrame window = new JFrame("Sample Player Client 1");
private static class Ground extends JPanel {
private static final long serialVersionUID = 1L;
private int px = 50, py = 235, ex, ey, key;
private DataWriter writer;
private DataReader reader;
private ActionListener timerListener = new ActionListener() {
public void actionPerformed(ActionEvent e) {
try {
writer.send(px, py);
System.out.println("data sent");
ex = reader.read().x;
ey = reader.read().y;
System.out.println("Data read");
} catch (IOException e1) {
e1.printStackTrace();
}
repaint();
}
};
private Timer animator = new Timer(30, timerListener);
private KeyAdapter keyListener = new KeyAdapter() {
public void keyPressed(KeyEvent e) {
key = e.getKeyCode();
if(key == KeyEvent.VK_UP) {
py -= 8;
if(py < 0) {
py = 0;
}
} else if(key == KeyEvent.VK_DOWN) {
py += 8;
if(py > 430) {
py = 430;
}
} else if(key == KeyEvent.VK_LEFT) {
px -= 8;
if(px < 0) {
px = 0;
}
} else if(key == KeyEvent.VK_RIGHT) {
px += 8;
if(px > 455) {
px = 455;
}
}
}
};
Ground() throws UnknownHostException, IOException {
Socket soc = new Socket(InetAddress.getByName("192.168.0.3"), 9998);
System.out.println("client 2 connected");
writer = new DataWriter(soc);
reader = new DataReader(soc);
animator.start();
addKeyListener(keyListener);
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
requestFocus();
g.setColor(Color.BLACK);
g.fillRect(px, py, 30, 30);
g.setColor(Color.RED);
g.fillRect(ex, ey, 30, 30);
}
}
private static class DataWriter {
private OutputStreamWriter writer;
private String point = "";
DataWriter(Socket soc) throws IOException {
writer = new OutputStreamWriter(soc.getOutputStream());
}
void send(int x, int y) throws IOException {
point = "" + x;
point += ",";
point += y;
point += "\n";
writer.write(point);
writer.flush();
}
}
private static class DataReader {
private InputStreamReader is;
private BufferedReader reader;
private String point = "";
DataReader(Socket soc) throws IOException {
is = new InputStreamReader(soc.getInputStream());
reader = new BufferedReader(is);
}
Point read() throws IOException {
point = reader.readLine();
int x = Integer.parseInt(point.split(",")[0]);
int y = Integer.parseInt(point.split(",")[1]);
return new Point(x, y);
}
}
public static void main(String [] args) throws UnknownHostException, IOException {
Ground ground = new Ground();
window.setContentPane(ground);
window.setSize(600, 600);
window.setLocation(0, 0);
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
window.setVisible(true);
}
}

Answer 1

I don't see the problem but I did see that:
ex = reader.read().x;
ey = reader.read().y;
This reads two lines and throws away the y from the first and the x from the second.
Should be:
Point p = reader.read();
ex = p.x;
ey = p.y;
The peer might not generate a point for you to read every time you write one so the reading of the points from the peer should not occur in the event handler that writes a point to the peer.