Java - Error NullPointer Graphics java

f = new Figura("Rectangulo", 60, 70, 80, 50);

VS.add(f);

package Class;

import java.awt.BorderLayout;

import java.awt.Color;

import java.awt.Font;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JLabel;

public class VentanaServidor {

    public static JFrame VS;

    public static JButton btnServidor;

    JLabel etiqueta;

    public VentanaServidor() {

        VS = new Componentes().frame("[ Servidor ]", 600, 500, new BorderLayout());

        btnServidor = new Componentes().boton(" Circulo ");

        btnServidor.setFont(new java.awt.Font("Cambria", Font.PLAIN, 20));

        btnServidor.setFocusable(false);

        btnServidor.addActionListener(new Eventos());

        etiqueta = new Componentes().etiqueta("[ Servidor ]");

        etiqueta.setFont(new java.awt.Font("Cambria", Font.PLAIN, 30));

        etiqueta.setForeground(Color.DARK_GRAY);

        VS.add(etiqueta, BorderLayout.NORTH);

        VS.add(btnServidor, BorderLayout.SOUTH);

        VS.setVisible(true);

    }

}

package Class;

import java.awt.Color;

import java.awt.Graphics;

import java.awt.Graphics2D;

import javax.swing.JPanel;

public class Figura extends JPanel{

    String Figura;

    int Ancho, Alto;

    int x = 0, y = 0;

    public Figura(String Figura, int Ancho, int Alto, int x, int y){

        this.Figura = Figura;

        this.x = x;

        this.y = y;

        this.Ancho = Ancho;

        this.Alto = Alto;

    }

    //COORDENADAS DONDE SE INICIA A CONSTRUIR LA FIGURA

    //int x = 50, y = 50;

    @Override

    public void paint(Graphics g){

        //super.paint(g);

        Graphics2D g2d = (Graphics2D) g;

        g2d.setColor(Color.BLUE);

        if (Figura.equals("Circulo")) {

            g2d.drawOval(x, y, Ancho, Alto);

        }

        if(Figura.equals("Rectangulo")){

            g2d.drawRect(x, y, Ancho, Alto);

        }

    }

}

package Class;

import static Class.LinkCliente.flujoDatosSalida;

import static Class.VentanaCliente1.btnCliente1;

import static Class.VentanaServidor.VS;

import static Class.VentanaServidor.btnServidor;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

public class Eventos implements ActionListener {

    @Override

    public void actionPerformed(ActionEvent ae) {

        if (ae.getSource() == btnServidor) {

            Figura fg = new Figura("Circulo", 100, 100, 50, 50);

            System.out.println(fg);

            fg.repaint();

            VS.add(fg);

        }

        if (ae.getSource() == btnCliente1) {

            try {

                flujoDatosSalida.writeUTF("Rectangulo");

            } catch (Exception e) {

                System.out.println(e.getMessage());

            }

            Figura fgr = new Figura("Rectangulo", 70, 80, 80, 50);

            VS.add(fgr);

        }

    }

}