Help with Game Display structure and adding independant objects

Question

I'd like to do two things and I'm not sure how to set up the code.
1) Add 1 to n enemies that think and move on their own. Basically their own threaded life I think.
2) Add 1 to n weapons fire that when the thread is finished apply the damage.
Currently I'm only using Graphics2d to draw everything to an off screen image. The issue I have is that most of the individual object stuff is wrapped up in the main game loop rather than added to the object itself.
Here is my current working pseudo code: I have this working but seems like I need to make it more flexible. Just not sure how.
public class combatDisplay extends JPanel{
@Override
protected void paintComponent(Graphics g){
     creates Graphics2d offScreenImage
     wipeClean offScreenImage
     drawPlayers 0 to n
     drawSpaceShip 0 to n --> drawMe(offScreenImage);
     drawWeaponShots 0 to n
     drawExplosions 0 to n
     draw offScreenImage to panel
public void setPlayers (ArrayList al) {}
public void setObjects (ArrayList al) {}
public void setSpaceShips (ArrayList al) {}
public void setWeaponShots (ArrayList al) {}
public void setExplosions (ArrayList al) {}
class Spaceship{
     Point location
     Polygon shape
public void drawMe (BufferedImage bf){
     draw Polygon
class WeaponShot{
     Point location
     Polygon shape
public void drawMe (BufferedImage bf){
     draw Polygon
class GameLogicLoop {
     movePlayer
     moveEnemies
     fireWeapons
        applyDamage
}It seems like I should just spawn an enemy thread that checks its own ranges and does its own movements. But I'm not sure how to get that to display the offscreen image. Can an arraylist hold a thread?
Likewise, with the weapons fire.... it should be self contained to check hit, display itself, display explosion or hit, then apply damage to its target when animation is completed. These two seem like a similar code structure I'm just not sure how to set it up yet.
Any psuedocode would be helpful.

Answer 1

Morgalr,
Awesome responses thanks. Normally I don't code so it is an interesting (read hard) learning curve for me. Usually I just design and hire someone smarter than me to code.
If you don't mind taking a look, I tried reworking everything toward the approach we have been discussing. If you see anything glaring and troublesome, please yell.
Ship Class is its own thread that can paint itself. Basically it is a sitting ship.
DisplayPane is the image painting class.
loopGame tells the objects when to paint and passes the image reference around.
package controller;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Polygon;
import java.awt.image.BufferedImage;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Controller extends JFrame {
    DisplayPane pane;
    Ship satallite;
   public Controller(){
        setTitle("Controller");
        setBounds(0,0, 400, 400);
        setLayout(null);  //absolute position
        setResizable(false);
        pane = new DisplayPane(getBounds().width, getBounds().height);       
        add(pane);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLocationRelativeTo(null);
        setVisible(true);
   class DisplayPane extends JPanel{
       BufferedImage offImage;
       public DisplayPane(int width, int height){
           offImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
           setBounds(0, 0, width, height);
       @Override
       protected void paintComponent(Graphics g){
            g.drawImage(offImage,0,0,this);
       public BufferedImage getImage(){
           return offImage;
       public void setImage(BufferedImage tempImage){
           offImage = tempImage;
       public void wipeImage(){
            Graphics2D big = offImage.createGraphics();
            big.setColor(Color.BLACK);
            big.fillRect(0, 0, getBounds().width, getBounds().height);
   class Ship implements Runnable{
       Thread thread;
       int speedStep;
       boolean bAlive = true;
       Point point = new Point(0,0);
       public Ship(String shipName, int speed){
           thread = new Thread(this, shipName);
           speedStep = speed;
           point.x = (int) ((int) 300 * Math.random());
           point.y = (int) ((int) 300 * Math.random());
       public void start(){
           thread.start();
       public void kill(){
           bAlive = false;
       public void drawShip(BufferedImage tempImage){
            Graphics2D big = tempImage.createGraphics();
            int[] pXfrigate = {point.x, point.x-4, point.x-4, point.x+4, point.x+4};
            int[] pYfrigate = {point.y, point.y+7, point.y+17, point.y+17, point.y+7};
            Polygon frigateShape = new Polygon(pXfrigate, pYfrigate, 5);
            Polygon currentShip = frigateShape;
            big.setColor(Color.GRAY);
            big.fillPolygon(currentShip);
            big.setColor(Color.RED);
            big.drawPolygon(currentShip);
       public void run() {
           int delay = 500;
           while (bAlive){
               try{
                   System.out.println(thread.getName()+" x: "+point.x+" y: "+point.y);
                   Thread.currentThread().sleep(delay);
               }catch (Exception e){}
   public void loopGame(){
        satallite = new Ship("Dot", 0);
        satallite.start();
        while (isVisible()){
            pane.wipeImage();           
            satallite.drawShip(pane.getImage());
            pane.repaint();
            try{
                Thread.sleep(0);
            }catch (Exception e){}
            satallite.kill();           
        System.exit(0);
   public static void main(String[] args) {
        Controller control = new Controller();
        control.loopGame();
}