如何在Java当前类中引用来自其他类的实例

Question

I am working on bounding box collision of a laser colliding with a monster in Java. There is no problem with collision. The problem is the Rectangle object inside the OneEye class is static!

Problem 1: This is no problem if one monster was in the game but in my game I will be adding a lot of instances of the Monster class. So my Rectangle object cannot be static if I were to add more than one monster.

Problem 2: Note: if Rectangle object is non-static my getter method for Rectangle needs be non-static.

But I cannot seem to figure how to fix these two problems.

Again, my collision works! It is more of a code design flaw if I were to add different instances of the same class. To sum it all up, how do I refer to an instance from a different class in the current class I am writing code without referring to it in a static context.

Here's my code of two classes: Laser class and OneEye Class

public class Laser {

/* use a bounding box 
     * to test collision detection
     * 
     */
    private Rectangle rect;

   public void update(long milliseconds) {

// surround a bounding box around the laser
        rect = new Rectangle((int)position.x,(int)position.y,this.getWidth(),this.getHeight());
        // collision against the OneEye monster
        if(rect.intersects(OneEye.getRectangle()))
        {
            Game.getInstance().remove(this);
        }


}

public class OneEye {

/*
     * use bounding box
     * for collision 
     * detection
     */
    private static Rectangle rect;

public void update(long milliseconds) {

        // surround a bounding box around the oneEye monster
        rect = new Rectangle((int)position.x,(int)position.y,this.getWidth(),this.getHeight());
}

// can be useful for collision detection
public static  Rectangle getRectangle()
    {
        return rect;
    }
}

Answer 1

You definitely need to go the no-static route, without a doubt. Simply make the rect Rectangle variable and the getRectangle() method non static. If this causes further problems, then you will want to post the details of these problems.

Edit You state:

I tried that. But then the problem comes up: I cannot call getRectangle method (which is in my Monster class) in my Laser class.

The problem is not that you can't call getRectangle() in the Laser class, but rather that you can't call it on OneEye,. something that you've told us little about. I was assuming that OneEye is a Monster variable not a Monster subclass. If the latter, then your design is off as you should be calling methods on class instances, not on the classes themselves.

Edit 2
OK, now that I see OneEye, I see that it is a class, not an instance. Don't try to call methods off of this. Instead either create a oneEye variable that holds a Monster object, or a OneEye class that extends Monster, but either way, don't call getRectangle() on a class. Call it on a variable that refers to a Monster or Monster child class object.