存储程序中大多数类使用的数据的最佳方法是什么？

Question

To explain, i'm creating a simple game in Java using Swing. The size of the JFrame used is needed in a good deal of my classes. At first i just made a super class to contain the variables, but i am forced to find something different because Java only lets you extend once, and i need to use the super class for different reasons. If that makes sense.

I'm storing multiple instances of the same information in memory.

Variables such as:

JFrame height and width in pixels and tiles

Map height and width in pixels and tiles

"Tile" height and width

Here's some code to paint the picture better:

    protected static int SCREEN_WIDTH = 928;//Pixels
    protected static int SCREEN_HEIGHT = 672;//Pixels
    protected static int TILE_WIDTH = 32;//Pixels
    protected static int TILE_HEIGHT = 32;//Pixels
    protected int MAP_WIDTH = 1280;//Pixels
    protected int MAP_HEIGHT = 1280;//Pixels
    protected int MAP_WIDTHtile = MAP_WIDTH / TILE_WIDTH;
    protected int MAP_HEIGHTtile = MAP_HEIGHT / TILE_HEIGHT;
    protected static int XTILES = SCREEN_WIDTH / TILE_WIDTH;//how many tiles can fit on display x axis;
    protected static int YTILES = SCREEN_HEIGHT / TILE_HEIGHT;//how many tiles can fit on display y axis;
    protected ArrayList<BufferedImage> images;
    protected ArrayList<ArrayList<Integer>> displayArray2;
    protected ArrayList<ArrayList<Integer>> mapGlobal2;
    protected static int xIndex = 0;
    protected static int yIndex = 0;

Almost all of those variables are needed multiple classes throughout my entire program. And i'm declaring it multiple times as a result. I can't help but think i'm implementing this horribly and there has got to be a better way to do it. I also feel as though passing all this information through as parameters to class constructors isn't the best route.

Answer 1

Create a class just for those variables, instantiate it once and pass it around your code.

Make it static if there is only ever one instance.

You might even start adding methods so as to manipulate the data better.. ;-)

Answer 2

We take the JFrame example. For example: you need to set height of JFrame in another class MyClass. You may pass the JFrame instance variable in constructor of MyClass class. This is the constructor of Myclass.

public MyClass(JFrame frame){ this.frame = frame;}

when you instantiate MyClass, you pass your frame instance MyClass my = new MyClass(frame)

Now you have a handle of frame in your MyClass. Which you can use to call methods of frame any where such as fame.setHeight(450);

This approach is more logical and Object Oriented, as you are calling frame methods by using frame instance.