Java语言中继承和多态。

仿真农场一个哺乳动物类如下所示：publicclassMammal{protectedintage=2;protectedintweight=5;publicMammal(){System.out.println(“Mammalconstructor”);}intgetAge(){returnage;}voidsetAge(inta){age=a;}intgetWeight(){returnweight;}voidsetWeight(intw){weight=w;}voidmove(){System.out.println(“Mammalmoveone