java - Java通用继承

Question

我正在尝试实现一些以具有通用变量的父级开头的代码，然后子级继承它。

public class Parent <A>{
private A a;

public Parent (A a){
    this.a=a;
    }
} 

public class Child <A> extends Parent<A>{

private A a;

public Child (A a){
    this.a=a;
    }
}

我收到一个编译错误，指出

constructor Parent in class Parent<A> cannot be applied to given types; A

Answer 1

您需要从子级的构造函数显式调用父级的构造函数:

public class Child <A> extends Parent<A> {
    public Child (A a) {
        super(a);
    }
}