java：泛型|RandomList

泛型举例。作为容器的的另一个例子。假如我们需要构建一个可以应用于各种类型的对象工具，就需要用到泛型。举例：RandomList

public class RandomList<T> {
    private ArrayList<T> storage = new ArrayList<T>();
    private Random rand = new Random(47);

    public void add(T item) {//新增对象
        storage.add(item);
    }

    public T select() {//获取对象
        return storage.get(rand.nextInt(storage.size()));
    }

    public static void main(String[] args) {//测试
        RandomList<String> rs = new RandomList<String>();
        for (String s : ("The quick brown fox jumped over "
                + "the lazy brown dog").split(" "))
            rs.add(s);
        for (int i = 0; i < 11; i++)
            System.out.print(rs.select() + " ");
    }

}