计算器的设计与实现

设计一个能实现计算器功能的Java程序，可以进行加、减、乘、除（另外可适当加上阶乘、正弦、余弦和指数）运算。-Design and implementation of the calculator design a calculator function to achieve Java program, you can add, subtract, multiply, divide (also may be appropriate with factorial, sine, cosine and index) calculation.