Socket demo application

MyApplication.java

public class MyApplication {

    private Form current;

    public void init(Object context) {
        try {
            Resources theme = Resources.openLayered("/theme");
            UIManager.getInstance().setThemeProps(theme.getTheme(theme.getThemeResourceNames()[0]));
        } catch(IOException e){
            e.printStackTrace();
        }
    }
    
    public void start() {
        if(current != null){
            current.show();
            return;
        }
        final Form soc = new Form("Socket Test");
        Button btn = new Button("Create Server");
        Button connect = new Button("Connect");
        final TextField host = new TextField("127.0.0.1");
        btn.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent evt) {
                soc.addComponent(new Label("Listening: " + Socket.getIP()));
                soc.revalidate();
                Socket.listen(5557, SocketListenerCallback.class);
            }
        });
        connect.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent evt) {
                Socket.connect(host.getText(), 5557, new SocketConnection() {
                    @Override
                    public void connectionError(int errorCode, String message) {
                        System.out.println("Error");
                    }

                    @Override
                    public void connectionEstablished(InputStream is, OutputStream os) {
                        try {
                            int counter = 1;
                            while(isConnected()) {
                                os.write(("Hi: " + counter).getBytes());
                                counter++;
                                Thread.sleep(2000);
                            }
                        } catch(Exception err) {
                            err.printStackTrace();
                        }
                    }
                });
            }
        });
        soc.setLayout(new BoxLayout(BoxLayout.Y_AXIS));
        soc.addComponent(btn);
        soc.addComponent(connect);
        soc.addComponent(host);
        soc.show();
    }

    public static class SocketListenerCallback extends SocketConnection {
        private Label connectionLabel;

        @Override
        public void connectionError(int errorCode, String message) {
            System.out.println("Error");
        }

        private void updateLabel(final String t) {
            Display.getInstance().callSerially(new Runnable() {
                public void run() {
                    if(connectionLabel == null) {
                        connectionLabel = new Label(t);
                        Display.getInstance().getCurrent().addComponent(connectionLabel);
                    } else {
                        connectionLabel.setText(t);
                    }
                    Display.getInstance().getCurrent().revalidate();
                }
            });                        
        }

        @Override
        public void connectionEstablished(InputStream is, OutputStream os) {
            try {
                byte[] buffer = new byte[8192];
                while(isConnected()) {
                    int pending = is.available();
                    if(pending > 0) {
                        int size = is.read(buffer, 0, 8192);
                        if(size == -1) {
                            return;
                        }
                        if(size > 0) {
                            updateLabel(new String(buffer, 0, size));
                        }
                    } else {
                        Thread.sleep(50);
                    }
                }
            } catch(Exception err) {
                err.printStackTrace();
            }
        }
        
    }
    
    public void stop() {
        current = Display.getInstance().getCurrent();
    }
    
    public void destroy() {
    }

}