15.3泛型接口

泛型也可用于接口之中，我们可以使用泛型接口来生成工厂模式，当然在接口工厂是不需要任何参数的就会知道如何创建对象的

public interface Generator <T>{
   T next();
}
public class Coffe {
    private static long count=0;
    private final long id=count++;
    @Override
    public String toString() {
        return getClass().getSimpleName()+"  "+id;
    }
}
public class Americano extends Coffe{
}
public class Breve extends Coffe{
}
public class Cappuccino extends Coffe{
}
public class Latte extends Coffe {
}
public class Mocha extends Coffe{
}
public class CoffeeGenerator implements Generator<Coffe>{
    private Class[] types={Latte.class,Mocha.class,Cappuccino.class,Breve.class,Americano.class};
    private static Random random=new Random(47);
    public CoffeeGenerator(){ }
    @Override
    public Coffe next() {
        Coffe o=null;
        try {
           o = (Coffe) types[random.nextInt(types.length)].newInstance();
        } catch (Exception e) {
            System.out.println("对象创建失败");
        }
        return o;
    }
    public static void main(String[] args) {
        CoffeeGenerator coffeeGenerator = new CoffeeGenerator();
        for (int i = 0; i < 5; i++) {
            System.out.println(coffeeGenerator.next());
        }
    }
}