Java-Collision Detection for a projectile-2d Platform game

Question

我在目前正在努力制作的2D游戏中遇到碰撞检测问题。出于某种原因，我继续收到以下错误：

线程“Thread-2”中的异常java.lang.NullPointerException

at Objects.Bullet.Collision（Bullet.java:57）

at Objects.Bullet.tick（Bullet.java:39）

在window.Handler.tick（Handler.java:15）

在window.Game.tick（Game.java:96）

在window.Game.run（Game.java:76）

at java.lang.Thread.run（Unknown Source）

这里是我目前为我的子弹提供的代码：

package Objects;

import java.awt.Graphics;
import java.awt.Rectangle;
import java.util.LinkedList;

import window.Game;
import window.Handler;
import Framework.GameObject;
import Framework.ObjectId;
import Framework.Texture;



public class Bullet extends GameObject{

private float width=32,height=32; 

private final float MAX_SPEED = 10;
private Handler handler;
Texture tex= Game.getInstance();


public Bullet(float x,float y, ObjectId id,int velX){
    super(x,y,id);
    this.velX = velX;
}


public void tick(LinkedList<GameObject> object) {
    x+=velX;
    y+=velY;
    if(velX<0)orientation =-1;
    else if(velX>0)orientation=1;


        if(velY>MAX_SPEED){
            velY = MAX_SPEED;}
        Collision(object);
    }




public void render(Graphics g){
    g.drawImage(tex.bullet[0],(int)x ,(int)y,null);
}

public Rectangle getBoundsRight() {
    return new Rectangle((int) ((int)x+width-5),(int)y+5,(int)5,  (int)height-10);
}
public Rectangle getBoundsLeft() { 
    return new Rectangle((int)x,(int)y+5,(int)5,(int)height-10);
}

private void Collision(LinkedList<GameObject>object){
    for(int i=0; i<handler.object.size();i++){
    GameObject tempObject = handler.object.get(i);
    if(tempObject.getId() == ObjectId.Block){
        if(getBoundsRight().intersects(tempObject.getBounds())){
            velX=0;
            x = tempObject.getX()- width;
        }
        if(getBoundsLeft().intersects(tempObject.getBounds())){
            velX = 0;
            x = tempObject.getX()+ (30);
    }   
        }

    }

    }


public Rectangle getBounds() {
    return null;
}


}

我基本上复制了我的播放器类中的代码，其中一切都运行良好但由于某种原因我的子弹类错误

我的播放器类的代码如下所示：

package Objects;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Rectangle;
import java.util.LinkedList;

import window.Animation;
import window.Game;
import window.Handler;
import Framework.GameObject;
import Framework.ObjectId;
import Framework.Texture;

public class Player extends GameObject{
private float width = 64, height = 64;
private float gravity = 0.5f;
private final float MAX_SPEED = 10;
private Handler handler;
Texture tex = Game.getInstance();
//1= right
//-1= left
private Animation playerWalk,playerWalkLeft;

public Player(float x, float y,Handler handler, ObjectId id) {
    super(x, y, id);
    this.handler = handler;
    playerWalk = new Animation(5,tex.player[1],tex.player[2],tex.player[3],tex.player[4],tex.player[5],tex.player[6]);
    playerWalkLeft = new Animation(5,tex.player[7],tex.player[8],tex.player[9],tex.player[10],tex.player[11],tex.player[12]);

}


public void tick(LinkedList<GameObject> object) {
    x+=velX;
    y+=velY;
    if(velX<0)orientation =-1;
    else if(velX>0)orientation=1;

    if(falling||jumping){
        velY+=gravity;

        if(velY>MAX_SPEED){
            velY = MAX_SPEED;


        }

    }
    Collision(object);
    playerWalk.runAnimation();
    playerWalkLeft.runAnimation();

}
private void Collision(LinkedList<GameObject>object){
    for(int i=0; i<handler.object.size();i++){
        GameObject tempObject = handler.object.get(i);
        if(tempObject.getId() == ObjectId.Block){
        if(getBoundsTop().intersects(tempObject.getBounds())){
            y= tempObject.getY()+40 ;
            velY=0;
        }
            if(getBounds().intersects(tempObject.getBounds())){
                velY=0;
                y= tempObject.getY()-height;
                falling = false;
                jumping = false;
            }else
                falling = true;
            //Right
            if(getBoundsRight().intersects(tempObject.getBounds())){
                x = tempObject.getX()- width;
            }

            //Left
            if(getBoundsLeft().intersects(tempObject.getBounds())){
            x = tempObject.getX()+ (30);
            }




        }

    }
}


public void render(Graphics g) {
    g.setColor(Color.BLUE);
    if(velX != 0 ){
        if(orientation == 1)
            playerWalk.drawAnimation(g,(int)x,(int)y,64,64);
        else
            playerWalkLeft.drawAnimation(g,(int)x,(int)y,64,64);
    }else
        if(orientation == 1)
    g.drawImage(tex.player[1],(int)x,(int)y,64,64,null);    //change here to change the size of the ball. does not account for hit-box must change in the width and height global variables above
        else if(orientation == -1)
    g.drawImage(tex.player[12],(int)x,(int)y,64,64,null);
}



public Rectangle getBounds() {
    return new Rectangle((int) ((int)x+(width/2)-((width/2)/2)),(int) ((int)y+(height/2)),(int)width/2,(int)height/2);
}
public Rectangle getBoundsTop() {
    return new Rectangle((int) ((int)x+(width/2)-((width/2)/2)),(int)y,(int)width/2,(int)height/2);
}
public Rectangle getBoundsRight() {
    return new Rectangle((int) ((int)x+width-5),(int)y+5,(int)5,(int)height-10);
}
public Rectangle getBoundsLeft() {
    return new Rectangle((int)x,(int)y+5,(int)5,(int)height-10);
}

}

任何形式的帮助/提示或建议将不胜感激