说明：  本代码是关于java的键盘的输入,当你输入o是会弹出新窗口,当你输入其他是它会在最上一排显示你输入的字符,对学习java的同学是好例子
(the java code is on the keyboard input, when you enter o is the new pop-up window When you enter the other is that it will show your best suit the character input, to learn java students is a good example)