在参数中更改JFrame的大小

Question

好吧，所以我有一个名为Ball的类，我在构造函数中放置了一些参数。这里我有初始位置，大小和速度，但我还需要能够在参数中设置窗口（JFrame）的大小，以便在我调用例如ball（xpos，ypos，size，speed，windowx，windowy）它将根据我在windowx和windowy中放置的内容设置JFrame的大小。

现在我只是尝试像无头鸡一样的东西而不知道我在做什么：P，所以如果有人能指出我正确的方向，我将非常感激！

package com.company;

import javax.swing.*;
import java.awt.*;
import java.util.Random;


public class Main extends JPanel {


    static Ball[] balls = new Ball[20];
    Random rand = new Random();



    Main() {

        for(int i = 0; i<20;i++){
            float r = rand.nextFloat();
            float g = rand.nextFloat();
            float b = rand.nextFloat();
            Color randomColor = new Color(r, g, b);
            balls[i] = new Ball(Ball.randInt(100, 500),Ball.randInt(100, 500),Ball.randInt(10, 50),rand.nextInt(6-1)+1,randomColor,600,600);


        }
    }

    public void paintComponent(Graphics g) {

        super.paintComponent(g);
        Graphics2D g2 = (Graphics2D) g;
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        for(int i=0;i<20;i++) {
            balls[i].draw(g);
        }



    }



    public static void main(String[] args) throws InterruptedException{


        Main m = new Main();
        JFrame frame = new JFrame("Title"); //create a new window and set title on window
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //set the window to close when the cross in the corner is pressed
        frame.setSize(600,600);
        frame.add(m); //add the content of the game object to the window
        frame.setVisible(true); //make the window visible

        while(true){

            Thread.sleep(10);
            for(int i= 0;i<balls.length;i++){
                balls[i].update();
            }

            m.repaint();
        }


    }


}

球类：

 package com.company;

    import javax.swing.*;
    import java.awt.*;
    import java.util.Random;
    /**
     * Created by John on 25/02/2015.
     */

    public class Ball extends JPanel{
        float _speedX;
        float _speedY;
        int _size;
        float _x;
        float _y;
        float _speed;
        Color _color;
        int _windowX;
        int _windowY;




        Ball(int x, int y, int sz, float speed, Color c, int windowX, int windowY){
            _x = x;
            _y = y;
            _speed=speed;
            _speedX = speed;
            _speedY = speed;
            _size = sz;
            _color = c;
            _windowX = windowX;
            _windowY = windowY;



        }



        public void update(){

                _x += _speedX;
                _y += _speedY;

                if (_x+_size<0 || _x+_size>_windowX-_size){
                    _speedX*=-1;
                }

                if (_y+_size<0 || _y+_size>_windowY-_size){
                    _speedY*=-1;
                }



    this.repaint();


        }
        public static int randInt(int min, int max) {
            Random rand = new Random();
            int randomNum = rand.nextInt((max - min) + 1) + min;
            return randomNum;
        }

        public void draw(Graphics g) {
            g.setColor(_color);
            g.fillOval((int)_x,(int) _y, _size, _size);

        }



        public void setPreferredSize(int wX, int wY) {
            _windowX=wX;
            _windowY=wY;
            setPreferredSize(new Dimension(_windowX,_windowY));
        }
    }