2.　　 定义一个类Point，代表一个点，public属性有x和y，方法有显示点坐标 show（），构造函数有两个参数分别给x,y赋值，在main方法中构造两个对象，再创建一方法(getMiddle)为取两个点构成线段的中点的坐标，参数为2个点对象，调用此方法后得到一个新的点，编写Application，显示该对象的坐标值。- A class definition Point, represents a Point, public property have x and y, a method that Point coordinates show (), there are two arguments constructor respectively to x, y assignment, in the main method constructed of two objects, to create a method (getMiddle) to take two make the Point of the line of coordinate, parameters for 2 Point object, call this method after get a new Point, write Application, display the object coordinates.