Develop Reference

JPanels not being added to the JFrame

So I was building this very simple game and I've add all the elements (for the movement) but when I hit run it only shows me the JFrame and not the JPanel. I should mention that I am very new to Java and the code you see bellow might not be the cleanest (it's also not complete).
Main
public class Main {
public static void main(String[] args) {
GameFrame frame = new GameFrame();
}
}
GameFrame
public class GameFrame extends JFrame {
GamePanel panel;
GameFrame() {
panel = new GamePanel();
this.add(panel);
this.setTitle("Survival");
this.setResizable(false);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.pack();
this.setLocationRelativeTo(null);
this.setVisible(true);
}
}
Panel
public class GamePanel extends JPanel implements Runnable {
static final int GAME_WIDTH = 1000;
static final int GAME_HEIGHT = GAME_WIDTH * 9 / 16;
static final Dimension SCREEN_SIZE = new Dimension(GAME_WIDTH, GAME_HEIGHT);
static final int PLAYER_WIDTH = 40;
static final int PLAYER_HEIGHT = 40;
Thread gameThread;
Graphics graphics;
Player player;
int fireBallY = (int) (Math.random() * 563);
Fireballs fireball;
Image image;
int dimSky = 150;
GamePanel() {
newFireballs();
newPlayer();
this.setFocusable(true);
this.addKeyListener(new actionListener());
this.setPreferredSize(SCREEN_SIZE);
this.setBackground(Color.CYAN);
gameThread = new Thread(this);
gameThread.start();
}
private void newPlayer() {
player = new Player(200, 150, PLAYER_WIDTH, PLAYER_HEIGHT);
}
private void newFireballs() {
for (int i = 0; i < 5; i++) new Fireballs(800, fireBallY, PLAYER_WIDTH, PLAYER_HEIGHT);
}
public void paint(Graphics g) {
image = createImage(getWidth(), getHeight());
graphics = image.getGraphics();
draw(graphics);
g.drawImage(image, 0,0, this);
}
public void draw(Graphics g) {
player.draw(g);
}
public void move() {
player.moveX();
player.moveY();
}
public void collision() {}
public void run() {
//game loop
long lastTime = System.nanoTime();
double amountOfTicks = 60.0;
double ns = 1000000000 / amountOfTicks;
double delta = 0;
while (true) {
long now = System.nanoTime();
delta += (now - lastTime) / ns;
lastTime = now;
if (delta >= 1) {
move();
collision();
repaint();
delta--;
System.out.println("It Works!");
}
}
}
private class actionListener extends KeyAdapter {
public void keyPressed(KeyEvent e) {
player.KeyPressed(e);
}
public void keyReleased(KeyEvent e) {
player.KeyReleased(e);
}
}
}
Player
public class Player extends Rectangle {
int xVelocity;
int yVelocity;
int speed = 10;
public Player(int x, int y, int PLAYER_WIDTH, int PLAYER_HEIGHT) {
super(x,y, PLAYER_WIDTH, PLAYER_HEIGHT);
}
public void KeyPressed(KeyEvent e) {
if (e.getKeyCode() == KeyEvent.VK_W) {
setYDirection(-speed);
moveX();
moveY();
}
if (e.getKeyCode() == KeyEvent.VK_S) {
setYDirection(+speed);
moveX();
moveY();
}
if (e.getKeyCode() == KeyEvent.VK_D) {
setXDirection(+speed);
moveX();
moveY();
}
if (e.getKeyCode() == KeyEvent.VK_A) {
setXDirection(-speed);
moveX();
moveY();
}
}
public void KeyReleased(KeyEvent e) {
if (e.getKeyCode() == KeyEvent.VK_W) {
setYDirection(-10);
moveX();
moveY();
}
if (e.getKeyCode() == KeyEvent.VK_S) {
setYDirection(+1);
moveX();
moveY();
}
if (e.getKeyCode() == KeyEvent.VK_D) {
setXDirection(+1);
moveX();
moveY();
}
if (e.getKeyCode() == KeyEvent.VK_A) {
setXDirection(-1);
moveX();
moveY();
}
}
public void setXDirection(int xVelocity) {
x = x + xVelocity;
}
public void setYDirection(int yVelocity) {
y = y + yVelocity;
}
public void moveX() {
x = x + xVelocity;
}
public void moveY() {
y = y + yVelocity;
}
public void draw(Graphics g) {
g.setColor(Color.RED);
g.fillRect(x, y, width, height);
}
}
There are other classes but those are completely empty and I don't think they are the cause of my problem.

Several issues:
If you are new to Swing, do not start off with too much complexity.
when you cannot see a JPanel on screen, my approach would be first to amend that. Only then add some complexity to the JPanel itself.
I have done that below by simply displaying a big red JPanel.
Is the reason you do not see anything because you did not set a JFrame.size(Dimension d)? I have added that in the construtor of the JFrame
Indeed, as #Frakcool and #camickr have pointed out in their comments, the canonic approach in Swing is overriding JPanel.paintComponent(Graphics g)
You should obey the thread landscape that Swing has prepared for you. That is indeed use SwingWorker threads for background tasks as #Frakcool commented.
And also use the EventDispatchingThread to handle events and startup. In the main method below, you see the call to SwingUtilities.invokeLater(new Runnable()).
The more complex your application gets, the more likely you will run into trouble if not obeying the EventDispatchingThread.
here is my - minimal - sample code containing examples for the points above. Within your game logic may be further work to be done, which I think is out of scope.
import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class GameFrame extends JFrame {
GamePanel panel;
GameFrame() {
panel = new GamePanel();
this.add(panel);
this.setTitle("Survival");
this.pack();
/*
* might help to set a window size:
*/
setSize(800, 600);
this.setResizable(false);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setLocationRelativeTo(null);
this.setVisible(true);
}
private class GamePanel extends JPanel {
#Override
protected void paintComponent(Graphics g) {
// check if needed, eg for subcomponents
// super.paintComponent(g);
g.setColor(Color.red);
g.fillRect(0, 0, getWidth(), getHeight());
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new GameFrame();
}
});
}
}

Game in Java is not displaying

Hello everyone I am trying to make a game where the user plays as some kind of character, and trys to collect coins while avoiding monsters that spawn. My program compiles with no error, but nothing is showing up when I run the applet. This could be because of the order of extension I have everything in but I am not sure. Any help would be greatly appreciated (this is for a final school project for my intro to Java class). Here is the code, I know it is long but it all pertains to the question at hand:
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.util.*;
public class Sprite extends JApplet
{
Image image;
int x, y;
boolean isVisible;
public Sprite()
{
isVisible = false;
image = null;
}
public Sprite(Image i)
{
isVisible = true;
image = i;
x = 10;
y = 10;
}
public void setImage(Image img)
{
image = img;
isVisible = true;
}
public void setLocation(int _x, int _y)
{
x = _x;
y = _y;
}
public Rectangle getDimensions()
{
return new Rectangle(x, y, image.getWidth(null), image.getHeight(null));
}
public boolean intersects(Sprite s)
{
return getDimensions().intersects(s.getDimensions());
}
public void setVisible(boolean vis)
{
isVisible = vis;
}
public void paintComponent(Graphics g)
{
if(isVisible)
{
g.drawImage(image, x, y, null);
}
}
}
class Coins extends Sprite
{
int amount;
public Coins(int amt)
{
amount = amt;
}
public int getAmount()
{
return amount;
}
public void setAmount(int amt)
{
amount = amt;
}
}
class AnimateSprite extends Sprite
{
int speed = 5;
int directionX = 1, directionY = 1;
int healthPoints = 100;
final boolean DEAD = false;
final boolean ALIVE = true;
public void moveUp()
{
y -= speed;
}
public void moveDown()
{
y += speed;
}
public void moveLeft()
{
x -= speed;
}
public void moveRight()
{
x += speed;
}
public int getHealthPoints()
{
return healthPoints;
}
public void setHealthPoints(int hp)
{
healthPoints = hp;
}
public boolean hit(int amt)
{
healthPoints -= amt;
if(healthPoints < 0)
return DEAD;
else
return ALIVE;
}
}
class Game extends AnimateSprite implements Runnable, KeyListener
{
AnimateSprite user;
AnimateSprite monster, troll;
Coins ten, twenty;
Thread thread;
Random r;
public void init()
{
r = new Random();
user = new AnimateSprite();
user.setImage(getImage(getCodeBase(), "player.gif"));
monster = new AnimateSprite();
monster.setImage(getImage(getCodeBase(), "monster.gif"));
troll = new AnimateSprite();
troll.setImage(getImage(getCodeBase(), "monster.gif"));
troll.setLocation(350, 350);
setupCoins();
setFocusable(true);
addKeyListener(this);
thread = new Thread(this);
thread.start();
}
public void setupCoins()
{
ten = new Coins(10);
twenty = new Coins(20);
ten.setLocation(400, 350);
twenty.setLocation(450, 50);
ten.setImage(getImage(getCodeBase(), "coins.gif"));
twenty.setImage(getImage(getCodeBase(), "coins.gif"));
}
public void keyPressed(KeyEvent ke) //Event handling
{
int key = ke.getKeyCode();
if(key == KeyEvent.VK_UP)
user.moveUp();
else if(key == KeyEvent.VK_DOWN)
user.moveDown();
else if(key == KeyEvent.VK_LEFT)
user.moveLeft();
else if(key == KeyEvent.VK_RIGHT)
user.moveRight();
}
public void keyReleased(KeyEvent ke) {}
public void keyTyped(KeyEvent ke) {}
public void update(Graphics g) {paint(g);}
public void paint(Graphics g)
{
g.clearRect(0, 0, this.getWidth(), this.getHeight());
ten.paintComponent(g);
twenty.paintComponent(g);
monster.setLocation(r.nextInt(10) - 5 + monster.x, r.nextInt(10 - 5 + monster.y));
monster.paintComponent(g);
user.paintComponent(g);
if(user.intersects(monster))
{
g.setFont(new Font("Serif", Font.BOLD, 26));
g.drawString("YOU HAVE DIED, YOU LOSE!", 20, 100); //Prints this when you lose
thread.interrupt(); //Stopping the thread if you die
}
}
public void run()
{
try //Try catch
{
while(true) //Only does this while when the boolean is true
{
repaint();
Thread.sleep(10); //Thread sleeps
}
} catch(Exception e) {} //Exception handling
}
}

Your order of inheritance seems odd, but its not whats causing the problem. Take a look at this website: http://www.dreamincode.net/forums/topic/28410-application-to-japplet-and-reverse/
Java Applets need to have init(), start(), stop(), and destroy(). You will need to put these methods in your Sprite class for the Applet to function.

Creating multiple instances of an object. (Game)

I've been asked to make a game for my CS (high school) class as my end of semester assignment. We haven't been taught properly all of the coding required to make a game so my knowledge in this area is very poor. Anyways, the game I am trying to make is something like "Flappy Fall" (an Apple appstore game) where objects fall from the top of the screen and descend to the bottom of the screen. The objective is to catch these objects before they reach the bottom. I am able to get one object to fall and have also created the "catcher", but I am not sure how to create multiple falling objects, nor do I know how to remove the object once it has been caught by the catcher. So far I have classes "JavaGame", "Catcher", and "Ball". Any help would be greatly appreciated.
int x, y;
int t = 1;
private Image dbImage;
private Graphics dbGraphics;
Image player;
Image bkg;
static Catcher p = new Catcher(150, 450);
public JavaGame() {
//Game Images
ImageIcon b = new ImageIcon("bkg.png");
bkg = b.getImage();
//Game properties
setTitle("Game");
setSize(350, 600);
setResizable(false);
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationRelativeTo(null);
addKeyListener(new Keys());
addMouseMotionListener(new Mouse());
}
public void paint(Graphics g) {
//
dbImage = createImage(getWidth(), getHeight());
dbGraphics = dbImage.getGraphics();
draw(dbGraphics);
g.drawImage(dbImage, 0, 0, this);
}
public void draw(Graphics g) {
g.drawImage(bkg, 0, 0, this); //Creates background
p.draw(g);
//while (t < 100) {
p.b.draw(g);
//t++;
//}
g.setColor(Color.WHITE);
g.drawString(""+p.score, 175, 50);
repaint();
}
public static void main(String[] args) {
JavaGame jg = new JavaGame();
//Threads
Thread p1 = new Thread(p);
p1.start();
Thread ball = new Thread(p.b);
ball.start();
}
public class Keys extends KeyAdapter {
public void keyPressed(KeyEvent e) {
p.keyPressed(e);
}
public void keyReleased(KeyEvent e) {
p.keyReleased(e);
}
}
public class Mouse implements MouseMotionListener {
public void mouseDragged(MouseEvent e) {
p.mouseDragged(e);
}
public void mouseMoved(MouseEvent e) {
p.mouseMoved(e);
}
}
}
int x, y, ranX, xDirection;
int score;
Rectangle catch1;
Ball b = new Ball(170, 1);
public Catcher (int x, int y) {
score = 0;
this.x = x;
this.y = y;
catch1 = new Rectangle(this.x, this.y, 50, 15);
}
public void run() {
try {
while(true) {
move();
Thread.sleep(5);
}
}
catch(Exception e) {
System.out.println("Error");
}
}
public void collision() {
if (b.ball.intersects(catch1)) {
b.ball(Color.blue);
score++;
System.out.println(score);
}
}
public void move() {
collision();
catch1.x += xDirection;
if (catch1.x <= 0)
catch1.x = 0;
if (catch1.x >= 300)
catch1.x = 300;
}
public void setXDirection(int xDir) {
xDirection = xDir;
}
public void keyPressed(KeyEvent m) {
int keyCode = m.getKeyCode();
if (keyCode == m.VK_LEFT) {
setXDirection(-1);
}
if (keyCode == m.VK_RIGHT) {
setXDirection(+1);
}
m.consume();
}
public void keyReleased(KeyEvent m) {
int keyCode = m.getKeyCode();
if (keyCode == m.VK_LEFT) {
setXDirection(0);
}
if (keyCode == m.VK_RIGHT) {
setXDirection(0);
}
m.consume();
}
public void mouseDragged(MouseEvent e) {
catch1.x = e.getX()-25;
e.consume();
}
public void mouseMoved(MouseEvent e) {
catch1.x = e.getX()-25;
e.consume();
}
public void draw(Graphics g) {
g.fillRect(catch1.x, catch1.y, catch1.width, catch1.height);
}
}
int x, y, yDirection;
Rectangle ball;
public Ball (int x, int y) {
this.x = x;
this.y = y;
ball = new Rectangle(this.x, this.y, 10, 10);
}
public void run() {
try{
while(true) {
move();
Thread.sleep(5);
}
}
catch(Exception e) {
System.out.println("Error");
}
}
public void move() {
if (ball.y >= 600) {
ball.y = 600;
}
if (ball.y > 0) {
ball.y++;
}
}
public void setYDirection(int yDir) {
yDirection = yDir;
}
public void draw(Graphics g) {
g.setColor(Color.WHITE);
g.fillRect(ball.x, ball.y, ball.width, ball.height);
System.out.println(ball.x+ " "+ ball.y+ " " + ball.width + " " + ball.height);
}
}

I'd re-organize the code a little. In the main game, you can have a collection of 'Ball' types. I'll leave the collection option up to you. But you'll want to add 'new' Balls to the collection and then remove them once they are caught.

Since I do not want to do your assignment, I am just giving a short answer:
By calling new Ball() multiple times.
Of course you might want to add them to a collection, like
List list = new ArrayList();
list.add(ball);
And remove them from that collection once they are finished.

Changing image immediately

I am currently trying to learn a little bit about programming games.
I got myself a player class extending a sprite class i wrote by myself.
Now i want to know, how i can change the image of my player object in the middle of the running game. imagine a spaceship, when pressing the right arrow key it should be a different image, inclined to the right.
now i am trying to do this:
when a button is pressed (e.g. space) setImage(the new image)
But now, when i call this method my image just disappears and the new one won't appear?
Any ideas?
My code of the Main class:
public class Game extends JPanel implements Runnable{
private static final long serialVersionUID = 1L;
public boolean isRunning;
public static final int WIDTH = 320;
public static final int HEIGHT = 240;
public static final int SCALE = 2;
private Player player;
public Game() {
addKeyListener(new TAdapter());
setFocusable(true);
requestFocus();
start();
}
public void start() {
isRunning = true;
new Thread(this).start();
}
public void stop() {
isRunning = false;
}
public void run() {
init();
while(isRunning) {
update();
repaint();
try {
Thread.sleep(5);
} catch (Exception e) {
e.printStackTrace();
}
}
}
public void init() {
player = new Player("/ship_blue", WIDTH - 32/2, 400);
}
public void update() {
player.update();
}
public void paint(Graphics g) {
super.paint(g);
Graphics2D g2d = (Graphics2D)g;
drawPlayer(g2d);
}
public void drawPlayer(Graphics2D g2d) {
if(player.isVisible)g2d.drawImage(player.getImage(),(int) player.getX(), (int) player.getY(), null);
}
public static void main(String[] args) {
Game gameComponent = new Game();
Dimension size = new Dimension(WIDTH*SCALE, HEIGHT*SCALE);
JFrame frame = new JFrame("Invaders");
frame.setVisible(true);
frame.setSize(size);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setResizable(false);
frame.add(gameComponent);
}
public class TAdapter extends KeyAdapter{
public void keyPressed(KeyEvent e) {
player.keyPressed(e);
}
public void keyReleased(KeyEvent e) {
player.keyReleased(e);
}
}
}
That's the main class, now the player class in which i am trying to change the image in the onPress() method:
public class Player extends Sprite{
private double glideSpeed = .125;
private int fixY;
private int xDirection = 0;
private int yDirection = 1;
public Player(String source, int x, int y) {
this.x = x;
this.y = y;
ImageIcon ii = new ImageIcon(this.getClass().getResource(source));
setImage(ii.getImage());
setTileSize(ii.getIconWidth());
setSpeed(0.2);
fixY = y;
}
public void update() {
x += xDirection * 1.4;
glide(10);
}
public void keyPressed(KeyEvent e) {
int key = e.getKeyCode();
if(key == KeyEvent.VK_RIGHT) {
xDirection = 1;
}
if(key == KeyEvent.VK_LEFT) {
xDirection = -1;
}
if(key == KeyEvent.VK_SPACE) {
ImageIcon ii2 = new ImageIcon("/player_blue_negativ");
setImage(ii2.getImage()); //<-----Here I am trying to change the image
}
}
public void keyReleased(KeyEvent e) {
int key = e.getKeyCode();
if(key == KeyEvent.VK_RIGHT || key == KeyEvent.VK_LEFT) {
xDirection = 0;
}
}
public void glide(int span) {
y += yDirection * glideSpeed;
if(y - fixY > span || fixY - y > span) {
yDirection = -yDirection;
}
}
}
And to complete everything here's my sprite class:
public class Sprite {
protected double x;
protected double y;
protected int tileSize;
protected double speed;
protected Image img;
protected boolean isVisible;
public Sprite() {
isVisible = true;
}
public double getSpeed() {
return speed;
}
public double getX() {
return x;
}
public double getY() {
return y;
}
public int getTileSize() {
return tileSize;
}
public Image getImage() {
return img;
}
public boolean getVisible() {
return isVisible;
}
public void setSpeed(double speed) {
this.speed = speed;
}
public void setX(double x) {
this.x = x;
}
public void setY(double y) {
this.y = y;
}
public void setTileSize(int tileSize) {
this.tileSize = tileSize;
}
public void setImage(Image img) {
this.img = img;
}
public void die() {
isVisible = false;
}
}

if(key == KeyEvent.VK_SPACE) {
ImageIcon ii2 = new ImageIcon("/player_blue_negativ");
There is the basic problem. All images should be loaded and cached prior to an event happening. When the event occurs, use the cached image and the GUI should render immediately.
As mentioned by #camickr, the use of an ImageIcon also subtly slips from an URL to a String (presumed to represent a
File path). Stick with the URL obtained from getResource(..).
On ImageObserver.
If an ImageObserver is used to paint the image, the observer will be informed of updates to images that are asynchronously loaded. All components (e.g. JPanel) implement ImageObserver, so..
g2d.drawImage(player.getImage(),(int) player.getX(), (int) player.getY(), null);
Should be:
g2d.drawImage(player.getImage(),(int) player.getX(), (int) player.getY(), this);
Free the EDT!
class Game extends JPanel implements Runnable ..
Thread.sleep(5);
Don't block the EDT (Event Dispatch Thread) - the GUI will 'freeze' when that happens.
Also don't attempt to update the GUI from anything other than the EDT.
Instead of calling Thread.sleep(n) in a Runnable, implement a Swing Timer for repeating tasks or a SwingWorker for long running tasks. See Concurrency in Swing for more details.
Use paintComponent(Graphics) for Swing components!
public void paint(Graphics g) {
Should be:
#Override
public void paintComponent(Graphics g) {

When you load the initial image you use the following without a problem:
ImageIcon ii = new ImageIcon(this.getClass().getResource(source));
When you change the image you use:
ImageIcon ii2 = new ImageIcon("/player_blue_negativ");
I'm guessing you don't find the image, probably because you don't need the "/". But why not use the same method that you know works?

Why does the height of the rectangles jump vary?

Why does the height of the rectangle's jump vary? It seems to go in a cycle. First it jumps low then it doesn't jump at all then it jumps high then it doesn't jump at all. i can't figure out why as the same code is used and it is triggered by the same event.
import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.event.KeyEvent;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.JFrame;
import javax.swing.JPanel;
#SuppressWarnings("serial")
class Game extends JPanel{
Square square = new Square(this);
Ground ground = new Ground (this);
public Game() {
addKeyListener(new KeyListener() {
#Override
public void keyTyped(KeyEvent e) {
}
#Override
public void keyReleased(KeyEvent e) {
square.keyReleased(e);
}
#Override
public void keyPressed(KeyEvent e) {
square.keyPressed(e);
}
});
setFocusable(true);
}
public static void main(String[] args) throws InterruptedException {
JFrame frame = new JFrame("My Mario");
Game game = new Game();
frame.add(game);
frame.setSize(600, 700);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
while (true) {
game.move();
game.repaint();
Thread.sleep(30);
}
}
private void move() {
square.move();
}
#Override
public void paint(Graphics g) {
super.paint(g);
Graphics2D g2d = (Graphics2D) g;
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
square.paint(g2d);
ground.paint(g2d);
}
}
public class Square {
Square square;
int x,xa;
static int y;
int ya;
private Game game;
public static int fistX,fistY;
static int d = 60;
int wide;
boolean onGround;
public Square(Game game) {
this.game = game;
x = 100;
y = 631;
xa = 0;
ya = 0;
onGround = false;
wide = game.getWidth();
}
public void move() {
if (x + xa > 0 && x + xa < game.getWidth()-30)
x = x + xa;
if (y + ya > 0 && y + ya < game.getHeight()-60){
for(int i=12; i< 0; i--);
ya+=10;
y = y + ya;
}
if ( collision() ) {
y-=10;
onGround = true;
}
Square.y+=10;
}
public void paint(Graphics2D g) {
g.setColor(Color.RED);
g.fillRoundRect(x, y-d, 30, d, 10, 10);
}
private boolean collision() {
return game.ground.getBounds().intersects(getBounds());
}
public Rectangle getBounds() {
return new Rectangle(x, y, 30, 60);
}
public void keyReleased(KeyEvent e) {
if (e.getKeyCode() == KeyEvent.VK_LEFT)
xa=0;
if (e.getKeyCode() == KeyEvent.VK_RIGHT)
xa=0;
if(e.getKeyCode() == KeyEvent.VK_DOWN)
d = 60;
if(e.getKeyCode() == KeyEvent.VK_UP);
}
public void keyPressed(KeyEvent e) {
// TODO Auto-generated method stub
if (e.getKeyCode() == KeyEvent.VK_LEFT)
xa = xa -3;
if (e.getKeyCode() == KeyEvent.VK_RIGHT)
xa = xa + 3;
if(e.getKeyCode() == KeyEvent.VK_DOWN)
d = 30;
if(e.getKeyCode() == KeyEvent.VK_UP)
ya -= 60;
}
}
class Ground {
int y,x,h,w;
public Ground(Game game){
x = 0;
y = game.getHeight()-30;
w = game.getWidth();
h = 30;
}
public void paint(Graphics2D g){
g.setColor(Color.BLACK);
g.fillRect(0, 700, 99999999, 30);
}
public Rectangle getBounds() {
return new Rectangle(0, 700, 99999999, 30);
}
}

Don't block the EDT (Event Dispatch Thread) - the GUI will 'freeze' when that happens. Instead of calling Thread.sleep(n) implement a Swing Timer for repeated tasks like animation. See Concurrency in Swing for more details.
frame.setSize(600, 700); I recommend instead setting a preferred size for the content and packing the frame around it. This suggests a constant size for the game on different PLAFs or OS'.
For Swing components other than top-level containers (e.g JFrame or JWindow), override paintComponent(Graphics) rather than paint(Graphics).
Look into key bindings instead of key listeners for Swing.
The first 3 are implemented, the last one (and other one commented in the code) is TODO - BNI.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
class SuperMarioGame extends JPanel {
private static final long serialVersionUID = 1L;
Square square = new Square(this);
Ground ground = new Ground (this);
public SuperMarioGame() {
// TODO Update to Key Bindings
addKeyListener(new KeyListener() {
#Override
public void keyTyped(KeyEvent e) {
}
#Override
public void keyReleased(KeyEvent e) {
square.keyReleased(e);
}
#Override
public void keyPressed(KeyEvent e) {
square.keyPressed(e);
}
});
setFocusable(true);
// Use a listener/timer combo.
ActionListener gameAnimation = new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
move();
repaint();
}
};
Timer timer = new Timer(30,gameAnimation);
timer.start();
// Set a preferred size for the panel.
Dimension preferred = new Dimension(600,700);
this.setPreferredSize(preferred);
}
public static void main(String[] args) throws InterruptedException {
JFrame frame = new JFrame("My Mario");
SuperMarioGame game = new SuperMarioGame();
frame.add(game);
// Pack the frame to the preferred size.
frame.pack();
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
private void move() {
square.move();
}
#Override
// for Swing components, generally override
// paintComponent rather than paint
//public void paint(Graphics g) {
public void paintComponent(Graphics g) {
super.paint(g);
Graphics2D g2d = (Graphics2D) g;
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
square.paint(g2d);
ground.paint(g2d);
}
}
class Square {
Square square;
int x,xa;
static int y;
int ya;
private SuperMarioGame game;
public static int fistX,fistY;
static int d = 60;
int wide;
boolean onGround;
public Square(SuperMarioGame game) {
this.game = game;
x = 100;
y = 631;
xa = 0;
ya = 0;
onGround = false;
wide = game.getWidth();
}
public void move() {
if (x + xa > 0 && x + xa < game.getWidth()-30)
x = x + xa;
if (y + ya > 0 && y + ya < game.getHeight()-60){
for(int i=12; i< 0; i--);
ya+=10;
y = y + ya;
}
if ( collision() ) {
y-=10;
onGround = true;
}
Square.y+=10;
}
public void paint(Graphics2D g) {
g.setColor(Color.RED);
g.fillRoundRect(x, y-d, 30, d, 10, 10);
}
private boolean collision() {
return game.ground.getBounds().intersects(getBounds());
}
public Rectangle getBounds() {
return new Rectangle(x, y, 30, 60);
}
public void keyReleased(KeyEvent e) {
// TODO Else-if would be better here..
if (e.getKeyCode() == KeyEvent.VK_LEFT)
xa=0;
if (e.getKeyCode() == KeyEvent.VK_RIGHT)
xa=0;
if(e.getKeyCode() == KeyEvent.VK_DOWN)
d = 60;
if(e.getKeyCode() == KeyEvent.VK_UP);
}
public void keyPressed(KeyEvent e) {
// TODO Else-if would be better here..
if (e.getKeyCode() == KeyEvent.VK_LEFT)
xa = xa -3;
if (e.getKeyCode() == KeyEvent.VK_RIGHT)
xa = xa + 3;
if(e.getKeyCode() == KeyEvent.VK_DOWN)
d = 30;
if(e.getKeyCode() == KeyEvent.VK_UP)
ya -= 60;
}
}
class Ground {
int y,x,h,w;
public Ground(SuperMarioGame game){
x = 0;
y = game.getHeight()-30;
w = game.getWidth();
h = 30;
}
public void paint(Graphics2D g){
g.setColor(Color.BLACK);
g.fillRect(0, 700, 99999999, 30);
}
public Rectangle getBounds() {
return new Rectangle(0, 700, 99999999, 30);
}
}

Don't block the Event Dispatching Thread any way, it will prevent the EDT from processing repaint requests (and other events) which will make it look like your program has crashed. Have a read of Concurrency in Swing for more information.
Only modify the UI from the EDT, NEVER from any other thread, this includes creating UI elements
Favor key bindings over KeyListeners, they are more capable of resolving focus issues amongst other things. Have a read of How to Use Key Bindings for more details
Favor overriding paintComponent rather then paint. Paint does a lot of important work which you should avoid messing with if you can. Apart from any thing else paintComponent is going to be included in the double buffering of the component where as paint isn't (as super.paint sets it up)
Avoid using static state variables where possible
I don't know if this was deliberate or not, but, for (int i = 12; i < 0; i--); isn't going to achive anything, as the semi colen at the end means, do nothing for a count of 1
Personally, try not to use absolute values for things like width and height, which is actually reliant on parent container. You should also, where possible, provide sizing hints to allow the parent container to make better decisions on how much space it actually needs
UPDATED
Fixed bug in my movement code :P
I had a look at your collision detection code (in move) and, frankly, couldn't make heads or tails of it. I corrected it as well as changed in the way the paint method works so that x,y is always the top, left corner
public class TestGame {
public static void main(String[] args) throws InterruptedException {
new TestGame();
}
public TestGame() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException ex) {
} catch (InstantiationException ex) {
} catch (IllegalAccessException ex) {
} catch (UnsupportedLookAndFeelException ex) {
}
Game game = new Game();
JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(game);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class GameThread extends Thread {
private Game game;
public GameThread(Game game) {
setDaemon(false);
this.game = game;
}
#Override
public void run() {
while (true) {
game.move();
try {
long startedAt = System.currentTimeMillis();
SwingUtilities.invokeAndWait(new Runnable() {
#Override
public void run() {
game.repaint();
}
});
long completedAt = System.currentTimeMillis();
long sleepFor = 30 - (completedAt - startedAt);
if (sleepFor < 0) {
sleepFor = 30;
}
Thread.sleep(sleepFor);
} catch (Exception exp) {
exp.printStackTrace();
}
}
}
}
public class Game extends JPanel {
Square square = new Square(this);
Ground ground = new Ground(this);
public Game() {
// addKeyListener(new KeyListener() {
// #Override
// public void keyTyped(KeyEvent e) {
// }
//
// #Override
// public void keyReleased(KeyEvent e) {
// square.keyReleased(e);
// }
//
// #Override
// public void keyPressed(KeyEvent e) {
// square.keyPressed(e);
// }
// });
setFocusable(true);
InputMap im = getInputMap(WHEN_IN_FOCUSED_WINDOW);
ActionMap am = getActionMap();
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_LEFT, 0, false), "press-left");
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_RIGHT, 0, false), "press-right");
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_DOWN, 0, false), "press-down");
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_UP, 0, false), "press-up");
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_LEFT, 0, true), "release-left");
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_RIGHT, 0, true), "release-right");
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_DOWN, 0, true), "release-down");
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_UP, 0, true), "release-up");
am.put("press-left", new PressLeftAction(square));
am.put("press-right", new PressRightAction(square));
am.put("press-down", new PressDownAction(square));
am.put("press-up", new PressUpAction(square));
am.put("release-left", new ReleaseLeftAction(square));
am.put("release-right", new ReleaseRightAction(square));
am.put("release-down", new ReleaseDownAction(square));
am.put("release-up", new ReleaseUpAction(square));
new GameThread(this).start();
// public void keyReleased(KeyEvent e) {
//
//
//
// if (e.getKeyCode() == KeyEvent.VK_LEFT) {
// xa = 0;
// }
//
// if (e.getKeyCode() == KeyEvent.VK_RIGHT) {
// xa = 0;
// }
// if (e.getKeyCode() == KeyEvent.VK_DOWN) {
// d = 60;
// }
//
// if (e.getKeyCode() == KeyEvent.VK_UP);
// }
//
// public void keyPressed(KeyEvent e) {
//// TODO Auto-generated method stub
// if (e.getKeyCode() == KeyEvent.VK_LEFT) {
// xa = xa - 3;
// }
//
// if (e.getKeyCode() == KeyEvent.VK_RIGHT) {
// xa = xa + 3;
// }
//
// if (e.getKeyCode() == KeyEvent.VK_DOWN) {
// d = 30;
// }
//
// if (e.getKeyCode() == KeyEvent.VK_UP) {
// ya -= 60;
// }
//
//
//
//
//
// }
}
public void move() {
square.move();
}
#Override
public Dimension getPreferredSize() {
return new Dimension(400, 400);
}
// Don't override paint, use paintComponent instead
// #Override
// public void paint(Graphics g) {
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
square.paint(g2d);
ground.paint(g2d);
g2d.dispose();
}
}
public class Square {
Square square;
private int x, xa;
// static int y;
private int y;
private int ya;
private Game game;
// public static int fistX, fistY;
private int fistX, fistY;
// static int d = 60;
private int d = 60;
private int wide;
private boolean onGround;
public Square(Game game) {
this.game = game;
x = 100;
y = 100;
xa = 0;
ya = 0;
onGround = false;
wide = game.getWidth();
}
public void move() {
y += ya;
x += xa;
if (x < 0) {
x = 0;
} else if (x + 30 > game.getWidth()) {
x = game.getWidth() - 30;
}
if (y < 0) {
y = 0;
} else if (collision()) {
onGround = true;
y = game.ground.getBounds().y - d;
}
// if (x + xa > 0 && x + xa < game.getWidth() - 30) {
// x = x + xa;
// }
//
// if (y + ya > 0 && y + ya < game.getHeight() - 60) {
// // This was never going to do anything, look at the
// // end of the line...the `;` is going to prevent the
// // statemt ya += 10 from begin called within the loop
//// for (int i = 12; i < 0; i--);
// for (int i = 12; i < 0; i--) {
// ya += 10;
// }
// y = y + ya;
// }
// if (collision()) {
// y -= 10;
// onGround = true;
//
// }
//
// y += 10;
}
public void paint(Graphics2D g) {
g.setColor(Color.RED);
System.out.println(x + "x" + (y - d));
g.fillRoundRect(x, y, 30, d, 10, 10);
}
private boolean collision() {
return game.ground.getBounds().intersects(getBounds());
}
public Rectangle getBounds() {
return new Rectangle(x, y, 30, 60);
}
}
public class Ground {
private Game game;
public Ground(Game game) {
this.game = game;
}
public void paint(Graphics2D g) {
g.setColor(Color.BLACK);
g.fillRect(0, game.getHeight() - 30, game.getWidth(), 30);
}
public Rectangle getBounds() {
return new Rectangle(0, game.getHeight() - 30, game.getWidth(), 30);
}
}
public abstract class AbstractSquareAction extends AbstractAction {
private Square square;
public AbstractSquareAction(Square square) {
this.square = square;
}
public Square getSquare() {
return square;
}
}
public class PressLeftAction extends AbstractSquareAction {
public PressLeftAction(Square square) {
super(square);
}
#Override
public void actionPerformed(ActionEvent e) {
getSquare().xa = -3;
System.out.println("pressLeft");
}
}
public class PressRightAction extends AbstractSquareAction {
public PressRightAction(Square square) {
super(square);
}
#Override
public void actionPerformed(ActionEvent e) {
getSquare().xa = 3;
}
}
public class PressDownAction extends AbstractSquareAction {
public PressDownAction(Square square) {
super(square);
}
#Override
public void actionPerformed(ActionEvent e) {
getSquare().ya = 30;
}
}
public class PressUpAction extends AbstractSquareAction {
public PressUpAction(Square square) {
super(square);
}
#Override
public void actionPerformed(ActionEvent e) {
getSquare().ya -= 30;
}
}
public class ReleaseLeftAction extends AbstractSquareAction {
public ReleaseLeftAction(Square square) {
super(square);
}
#Override
public void actionPerformed(ActionEvent e) {
getSquare().xa = 0;
}
}
public class ReleaseRightAction extends AbstractSquareAction {
public ReleaseRightAction(Square square) {
super(square);
}
#Override
public void actionPerformed(ActionEvent e) {
getSquare().xa = 0;
}
}
public class ReleaseDownAction extends AbstractSquareAction {
public ReleaseDownAction(Square square) {
super(square);
}
#Override
public void actionPerformed(ActionEvent e) {
getSquare().ya = 0;
}
}
public class ReleaseUpAction extends AbstractSquareAction {
public ReleaseUpAction(Square square) {
super(square);
}
#Override
public void actionPerformed(ActionEvent e) {
getSquare().ya = 0;
}
}
}