1）、定义一个抽象类Weapon,该抽象类有两个抽象方法attack()，move()：这两个方法分别表示武器的攻击方式和移动方式。

（2）、定义3个类：Tank,Flighter,WarShip都继承自Weapon,分别用不同的方式实现Weapon

类中的抽象方法。

（3）、写一个类Army,代表一支军队，这个类有一个属性是Weapon数组w（用来存储该军队所拥有的所有武器）；该类还提供一个构造方法，在构造方法里通过传一个int类型的参数来限定该类所能拥有的最大武器数量,并用这一大小来初始化数组w。该类还提供一个方法addWeapon(Weapon wa),表示把参数wa所代表的武器加入到数组w中。在这个类中还定义两个方法attackAll()和moveAll()，让w数组中的所有武器攻击和移动。

（4）、写一个主方法去测试以上程序。

-1), defines an abstract class Weapon, the abstract class has two abstract methods attack (), move (): These two methods represent the weapons attacks and moves.

(2), defines three classes: Tank, Flighter, WarShip are inherited from the Weapon, respectively, in different ways to achieve Weapon

　　　Class abstract methods.

(3), write a class Army, on behalf of an army, this class has a property is an array of Weapon w (used to store all of the weapons owned by the armed forces)　class provides a constructor in the constructor through the mass a parameter of type int to limit the class can have the maximum number of weapons, and to initialize the array with the size of the w. The class also provides a method addWeapon (Weapon wa), that represent the parameters wa added to the array w of weapons. In this class also defines two methods attackAll () and moveAll (), let w array and move all the weapons to attack.

(4), write a main method to test the above procedure.