java游戏开发限制数量随机对象

Question

我正在创造一个游戏。我需要随机创建对象，但我希望它们有一定数量。这是我随机创建的对象的主要类代码

private void randomTiles() {

    int randomXtile = new Random().nextInt(9500) + 20;
    int randomYtile = new Random().nextInt(12) + 0;
    Tile t = new Tile(randomXtile, randomYtile, 3);
    tilearray.add(t);
}

private void updateTiles() {
    randomTiles();
    for (int i = 0; i < tilearray.size(); i++) {
        Tile t = (Tile) tilearray.get(i);
        t.update();
    }
}

private void paintTiles(Graphics g) {
    for (int i = 0; i < tilearray.size(); i++) {
        Tile t = (Tile) tilearray.get(i);
        g.drawImage(t.getTileImage(), t.getTileX(), t.getTileY(), this);
    }
}

tile构造函数是

public Tile(int x, int y, int typeInt) {

    tileX = x * 40;
    tileY = y * 40;

    type = typeInt;
    r = new Rectangle();
    if (type == 5) {
        tileImage = StartingClass.tiledirt;
    } else if (type == 8) {
        tileImage = StartingClass.tilegrassTop;
    } else if (type == 4) {
        tileImage = StartingClass.tilegrassLeft;
    } else if (type == 6) {
        tileImage = StartingClass.tilegrassRight;

    } else if (type == 2) {
        tileImage = StartingClass.tilegrassBot;
    } else if (type == 3) {
        tileImage = StartingClass.ice;
        hp = 2;
    } else {
        type = 0;
    }

}

我的游戏对象中的某个地方应该来到某个坐标。你能帮我解决这个问题吗？