title: How to make sprite jump in java?
body: <p>I have KeyEvents for a sprite for moving left, right, up and down. I was just messing around and was thinking ahead for another project in which I want the sprite to jump. It doesn't have to be fully realistic as I am just beginning. What I have is when the space bar is pressed, it will cause the sprite to jump, lets say "dy = -3". So then I have the KeyEvent for keyReleased, it will fall, "dy = -2". This does not work as the sprite just continues to fall...can someone shine some light?</p>
  
  <p>Entire code:
          package collision;</p>
  
  <pre><code>    import java.awt.Image;
      import java.awt.Rectangle;
      import java.awt.event.KeyEvent;
  
      import java.util.ArrayList;
  
      import javax.swing.ImageIcon;
  
      public class Craft {
  
      private String craft = "pelican.png";
  
      private int dx;
      private int dy;
      private int x;
      private int y;
      private int width;
      private int height;
      private boolean visible;
      private Image image;
      private ArrayList missiles;
  
  
      public Craft() {
      ImageIcon ii = new ImageIcon(this.getClass().getResource(craft));
      image = ii.getImage();
      width = image.getWidth(null);
      height = image.getHeight(null);
      missiles = new ArrayList();
      visible = true;
      x = 100;
      y = 300;
      }
  
  
      public void move() {
  
      x += dx;
      y += dy;
  
      if (x &lt; 1) {
          x = 1;
      }
  
      if (y &lt; 1) {
          y = 1;
      }
  
      }
  
      public int getX() {
      return x;
      }
  
      public int getY() {
      return y;
      }
  
      public Image getImage() {
      return image;
      }
  
      public ArrayList getMissiles() {
      return missiles;
      }
  
      public void setVisible(boolean visible) {
      this.visible = visible;
      }
  
      public boolean isVisible() {
      return visible;
      }
  
       public Rectangle getBounds() {
      return new Rectangle(x, y, width, height);
      }
  
      public void keyPressed(KeyEvent e) {
  
      int key = e.getKeyCode();
  
      if (key == KeyEvent.VK_SPACE) {
  
      }
      if (key == KeyEvent.VK_V){
          dx = 6;
      }
  
      if (key == KeyEvent.VK_LEFT) {
          dx = -1;
      }
  
      if (key == KeyEvent.VK_RIGHT) {
          dx = 2;
      }
  
      if (key == KeyEvent.VK_UP) {
          dy = -1;
      }
  
      if (key == KeyEvent.VK_DOWN) {
          dy = 1;
      }
      }
  
      public void fire() {
      missiles.add(new Missile(x + width, y + height/2));
      }
  
      public void keyReleased(KeyEvent e) {
      int key = e.getKeyCode();
  
      if (key == KeyEvent.VK_LEFT) {
          dx = 0;
      }
      if (key == KeyEvent.VK_SPACE) {
  
      }
  
      if (key == KeyEvent.VK_RIGHT) {
          dx = 0;
      }
  
      if (key == KeyEvent.VK_UP) {
          dy = 0;
      }
  
      if (key == KeyEvent.VK_DOWN) {
          dy = 0;
      }
      }
      }
  </code></pre>
  
  <p>As you may have noticed Im new to Java as well as game programming. All I want is the sprite to go up, then come back down. It will always remain stationary if that helps. The sprite just keeps jumping until he is hit by an on coming obstacle. I know there is code for other movements, but those will be removed once I start on next sprite. </p>