一个java的简单计算器程序,这个程序并没有实现复杂的算法，仅仅是应用到了窗口的实现及运用。所以这个程序可以很好的学习了GUI知识-A java simple calculator program, this program does not implement complex algorithms are applied only to the realization and utilization of the window. Therefore, this procedure can be a good learning GUI knowledge