Java基于swing实现的弹球游戏代码(4)

                                }
                                // 如果选择退出按钮，则退出程序
                                if (command.equals("退出")) {
                                        System.exit(0);
                                }

                                // 如果选择简单按钮
                                if (command.equals("简单") && list.size() == 0) {

                                        creatBall(20, 1);
                                }

                                // 如果选择中等按钮
                                if (command.equals("中等") && list.size() == 0) {
                                        creatBall(50, 2);