编写一个Java应用程序，在其中编写一个类，该类封装了一元二次方程共有的属性和功能，即该类有刻画方程系数的3个成员变量以及计算实根的方法。并给出计算实根的过程-Write a Java application, in which the preparation of a class that encapsulates the properties of a total of one dollar quadratic equations and functions, that is, such a