复数表达式计算。要求：(1)声明复数类Complex提供复数加、减等运算，提供由字符串构造复数等异常。（2）设计jcomplex组件表示复数对象。（3）设计复数表达式计算的图形用户界面，输入多个复数，显示进行加、减等复数运算的结果，参加运算的复数个数可变；响应事件。-Calculation of complex expressions. Computing requirements: (1) Statement number class Complex complex addition, subtraction, etc., provided by the string constructor plural and other anomalies. (2) the design jcomplex component represents a complex object. (3) graphical user interface design complex expression evaluates to enter more than one complex, the result of a complex operation like addition, subtraction, computing complex variable number　respond to events.