扩展已经实现接口的抽象类的类是否需要接口？

Question

假设有一个代码:

package com.ps.Sample;

public interface Sample
{
    public void Method1();
}

public abstract class AbstractSample implements Sample
{
    public void Method1()
    {
        System.out.println("Hello World");
    }
}

public class MySample extends AbstractSample
{

}

public class TestSample
{
    public static void main(String[] args) 
    {
        Sample my = new MySample();

        my.Method1();
    }

}

我的问题是:宣布具体课程是否有任何好处

public class MySample extends AbstractSample implements Sample

代替

public class MySample extends AbstractSample 

Answer 1

不,那里没有.这是多余的.AbstractSample 是一个 Sample,MySample 是一个 AbstractSample.所以MySample 是一个样本.

无论你是否添加,javadoc都会显示所有已实现的接口implements Sample.