Slick Forums

public class Player extends Entity {
   
   public final String MOVE_LEFT= "left";
   public final String MOVE_RIGHT= "right";
   public final String CMD_FIRE= "fire";
   public boolean bulletOnScreen= false;
   
   public Player(int startX, int startY) throws SlickException {
      super(startX, startY);

      defineCommands();
      this.setGraphic(ResourceManager.getImage("spaceInvadersMain"));
      setHitBox(0, 0, currentImage.getWidth(), currentImage.getHeight());
      this.addType(SOLID);
   }
   
   public void render(GameContainer gameContainer, Graphics graphics) throws SlickException {
      super.render(gameContainer, graphics);
   }
   
   public void update(GameContainer gameContainer, int delta) throws SlickException {
      super.update(gameContainer, delta);
      dealWithInput();
   }
   
   private void dealWithInput() {
      if(check(MOVE_LEFT)) {
         moveLeft();
      } else if(check(MOVE_RIGHT)) {
         moveRight();
      } else if(pressed(CMD_FIRE)) {
         fireBullet();
      } else {
         this.speed.x= 0;
      }
   }
   
   private void moveLeft() {
      if(collide(SOLID, this.x - this.speed.x, this.y)== null   && this.x - this.speed.x > 30) {
         this.speed.x= -6;
      }
   }
   
   private void moveRight() {
      if(collide(SOLID, this.x + this.speed.x, this.y)== null   && this.x + this.speed.x + (float) this.height < 610) {
         this.speed.x= 6;
      }
   }
   
   private void fireBullet() {
      if(!bulletOnScreen) {
         
      }
   }
   
   private void defineCommands() {
      define(MOVE_LEFT, Input.KEY_LEFT);
      define(MOVE_RIGHT, Input.KEY_RIGHT);
      define(CMD_FIRE, Input.KEY_SPACE);
   }
}

Wed May 02 16:55:04 BST 2012 ERROR:null
java.lang.NullPointerException
   at actors.Player.dealWithInput(Player.java:44)
   at actors.Player.update(Player.java:33)
   at it.randomtower.engine.World.update(World.java:120)
   at states.GameplayState.update(GameplayState.java:45)
   at org.newdawn.slick.state.StateBasedGame.update(StateBasedGame.java:268)
   at org.newdawn.slick.GameContainer.updateAndRender(GameContainer.java:663)
   at org.newdawn.slick.AppGameContainer.gameLoop(AppGameContainer.java:411)
   at org.newdawn.slick.AppGameContainer.start(AppGameContainer.java:321)
   at game.SMGame.main(SMGame.java:29)