New to Java and trying to make a game

Question

I'm really new to Java so please try not to roll over laughing at the following code. At the moment, as you can hopefully pick up from the code, i'm trying to get a shape(Polygon) to respond to keyboard events and i'm trying to make the object primarily respond to the cursor keys and to move the Polygon in the corresponding directions of the cursors. I'm stuck and i think i have initialised everything but i can't get the shape to move. I'm pretty sure i'm missing required code in the paint method.
<code>
import java.awt.*;
import java.awt.Event.*;
import java.applet.*;
import java.io.*;
public class PlodInvaders extends Applet implements Runnable {
Point start, end, fire, shield, target;
int co_x, x, y;
int co_y;
int current_x, current_y;
char current_key;
Font theFont;
Thread th;
Image ship;
Polygon p;
public void init() {
setBackground(Color.black);
// mouse co-oridnates
co_x = this.size().width + 5;
co_y = this.size().height + 5;
theFont= new Font("Courier", Font.BOLD, 24);
current_x = 150;
current_y = 100;
public void start() {
th = new Thread(this);
th.start();
public boolean KeyDown(Event evt, int key) {
switch(key) {
case Event.LEFT: current_x = current_x - 10; break;
case Event.RIGHT: current_x = current_x +10; break;
case Event.UP: current_y = current_y + 10; break;
case Event.DOWN: current_y = current_y - 10; break;
default: current_key = (char) key;
start = new Point(x, y);
repaint();
return true;
public boolean MouseDown(Event evt, int x, int y) {
fire = new Point(x, y);
return true;
public boolean MouseUp(Event evt, int x, int y) {
target = new Point(x, y);
repaint();
return true;
public void run() {
public void paint(Graphics g){
Polygon p = new Polygon();
g.setColor(Color.white);
p.addPoint(20,20);
p.addPoint(50,25);
p.addPoint(50,50);
p.addPoint(25,50);
p.addPoint(20,20);
g.fillPolygon(p);
</code>

Answer 1

this is not prefect and it is not a applet, but it will make you start. you can email if you have any qeustions
import java.awt.*;
import java.awt.event.*;
public class MoveP extends Frame implements KeyListener
     Polygon po = new Polygon();
        int ix=0;
     int iy=0;
public MoveP()  
     addWindowListener(new WindowAdapter()
    {     public void windowClosing(WindowEvent ev)
          {     dispose();
               System.exit(0);
     addKeyListener(this);
     setSize(300,372);
     po.addPoint(20,20);
     po.addPoint(50,25);
     po.addPoint(50,50);
     po.addPoint(25,50);
     po.addPoint(20,20);
     setVisible(true); 
public void paint(Graphics g)
     g.setColor(Color.black);
     for (int i=0; i < po.npoints; i++)
          po.xpoints[i]+=ix;
          po.ypoints[i]+=iy;
     g.fillPolygon(po);
public void keyTyped(KeyEvent e)
public void keyPressed(KeyEvent e)
     ix = 0;
     iy = 0;
     int k = e.getKeyCode();
     if (k == 40) iy++;
     if (k == 38) iy--;
     if (k == 39) ix++;
     if (k == 37) ix--;
     repaint();
public void keyReleased(KeyEvent e)
public static void main (String[] args)
     new MoveP();
      Noah