限定泛型可用类型的相关应用

/*import  java.util.*;public class ListGenericTest<T extends List>//限定泛型的类型{private T []a;public void setA(T[] a){this.a=a;}public T[] getA(){return a;}public static void main(String[]args){ListGenericTest<ArrayList> array=new ListGenericTest<ArrayList>();//ArrayList []s={new ArrayList(),new ArrayList()};ArrayList []s=new ArrayList[10];array.setA(s);}}*/import java.util.*;public class ListGenericTest<T>{private T a;public void set (T a){this.a=a;}public T get(){return a;}public static void main(String[]args){ListGenericTest<? extends List> s;s=new ListGenericTest<ArrayList>();s=new ListGenericTest<LinkedList>();}}