java - 泛型和子类型

Question

Create a class with a generic type T. A subclass of the class that defines a second type parameter, called V. Call the methods from both classes using the object. Create 2 objects with different objects

这就是问题。

如果有人认为这不是家庭作业。我正在做一些 java 论文来练习。我不明白如何“用不同的对象创建 2 个对象”。谁能帮忙？

class Gen<T> 
 {
  T obj;
  Gen(T ob)
  {
    obj = ob;
  }

 T getobj()
  {
    return obj;
  }
}

class Gen2<T, V> extends Gen<T>
{
  V obj1;
  Gen2(T ob,V ob1)
   {
    super(ob);
    obj1 = ob1;
   }

 V getobj1()
 { 
    return obj1;
 }

}

public class Ch2Lu4Ex3 
 {
  public static void main(String args[]) 
    {
      Gen2<String,String> g = new Gen2<String,String>("robin","raj");        

      System.out.println(g.getobj1());
      System.out.println(g.getobj());
    }
 }

Answer 1

问题的最后一部分:

Create 2 objects with different objects

Gen2<Integer,String> inst = new Gen2<Integer,String>(1, "robin");