Simple Game - Need Help

[mitchbutter1210]

This is a simple game I'm trying to make. I'm trying to get it to where it will shoot a bullet and once you release the space bar i want it to keep going for a small amount of time but it won't. And occasionally it will crash

package game.practice;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;

import javax.swing.JFrame;

@SuppressWarnings("serial")
public class GamePractice extends JFrame implements Runnable {
	
	int x, y, xDirection, yDirection;
	static int bulletX;
	static int bulletY;
	Image dbImage;
	Graphics dbg;
	static boolean isShooting = false;

	public void run(){
		try{
			while(true){
				move();
				
				Thread.sleep(5);
			}
			}catch(Exception e){
				System.err.println(e.getMessage());
			}
		}
	
	public void move(){
		x += xDirection;
		y += yDirection;
		
		if(x <= 0){
			x = 0;
		}
		if(x >= 800){
			x = 800;
		}
		if(y <= 0){
			y = 0;
		}
		if(y >= 600){
			y = 600;
		}
	}
	
	public void setXDirection(int xdir){
		xDirection = xdir;
	}
	public void setYDirection(int ydir){
		yDirection = ydir;
	}
	
	public class AL extends KeyAdapter{
		public void keyPressed(KeyEvent e){
			int keyCode = e.getKeyCode();
			if(keyCode == KeyEvent.VK_LEFT){
				setXDirection(-1);
			}
			if(keyCode == KeyEvent.VK_RIGHT){
				setXDirection(+1);
			}
			if(keyCode == KeyEvent.VK_UP){
				setYDirection(-1);
			}
			if(keyCode == KeyEvent.VK_DOWN){
				setYDirection(+1);
			}
			if(keyCode == KeyEvent.VK_SPACE){
				isShooting = true;
			}
		}
		
		public void keyReleased(KeyEvent e){
			int keyCode = e.getKeyCode();
			if(keyCode == KeyEvent.VK_LEFT){
				setXDirection(0);
			}
			if(keyCode == KeyEvent.VK_RIGHT){
				setXDirection(0);
			}
			if(keyCode == KeyEvent.VK_UP){
				setYDirection(0);
			}
			if(keyCode == KeyEvent.VK_DOWN){
				setYDirection(0);
			}
			if(keyCode == KeyEvent.VK_SPACE){
				try {
					Thread.sleep(3000);
				} catch (InterruptedException e1) {
					e1.printStackTrace();
				}
				bulletX = x;
				bulletY = y;
				isShooting = false;
			}
		}
	}
	
	public GamePractice(){
		addKeyListener(new AL());
		setTitle("Mediocre Game -- Pre-Alpha -- Version 2.0 -- Created By: Mitchell Butterfield");
		setSize(800, 600);
		setLocationRelativeTo(null);
		setResizable(false);
		setVisible(true);
		setBackground(Color.BLUE);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		
		x = 400;
		y = 400;
	}
	
	public void paint(Graphics g){
		dbImage = createImage(getWidth(), getHeight());
		dbg = dbImage.getGraphics();
		paintComponent(dbg);
		if(isShooting == true){
			paintBullet(dbg);
		}
		g.drawImage(dbImage, 0, 0, this);
	}
	
	public void paintComponent(Graphics g){
		g.setColor(Color.DARK_GRAY);
		g.fillRect(x, y, 30, 30);
		g.setColor(Color.WHITE);
		g.drawString("X: " + x, 50, 50);
		g.drawString("Y: " + y, 50, 60);
		g.drawString("X Direction: " + xDirection, 50, 70);
		g.drawString("Y Direction: " + yDirection, 50, 80);
		g.drawString("Is Shooting: " + isShooting, 50, 90);
		g.drawString("Bullet X: " + bulletX, 50, 100);
		g.drawString("Bullet Y: " + bulletY, 50, 110);
		
		repaint();
	}
	
	public void paintBullet(Graphics g){
		g.fillOval(bulletX, bulletY, 5, 5);
		bulletY--;
	}
	
	public static void main(String[] args){
		GamePractice p = new GamePractice();
		Thread t1 = new Thread(p);
		t1.start();
	}
	}

[Fubarable]

Why are you calling paintComponent directly? And why does paintComponent have a repaint call in it? Both are dangerous things to do. Also you shouldn't even be coding in the paint method. It appears that you haven't gone through the Swing graphics tutorials yet, and I recommend that you do this first. Then look into using a Swing Timer.

[mitchbutter1210]

Thank you but the link doesn't seem to be working.

[DarrylBurke]

Something seems to have gone wrong with Fubarable's link. Here it is again: Lesson: Performing Custom Painting (The Java™ Tutorials > Creating a GUI With JFC/Swing)

db