java入门小程序。新建类；设定初始值，返回值；进行几何运算，比如：求圆的面积、周长，求圆柱体的表面积、体积；输出各种动物的叫声-Getting java applet. New Class　set the initial value, the return value　geometric operations such as: seeking the circular area, perimeter, seeking cylinder surface area, volume　the output of a variety of animal sounds