Inner Class & Anonymity

Posted 2020-12-16 nedrain

匿名子类 对 抽象类 而言， 匿名实现类 对 接口 而言

匿名子类

// Father.java
public abstract class Father {
    public abstract  void say();
}

// Say.java
public class Say {
    public void say(Father father){
        father.say();
    }
}

// Client.java
public class Client {
    public static void main(String[] args) {
        Say say = new Say();
        say.say(new Father() {
            @Override
            public void say() {
                System.out.println("I am the father.");
            }
        });
    }
}

匿名实现类

// Father.java    Here is the change
public interface Father {
    void say();
}

// Say.java
public class Say {
    public void say(Father father){
        father.say();
    }
}

// Client.java
public class Client {
    public static void main(String[] args) {
        Say say = new Say();
        say.say(new Father() {   // @Override is not allowed in implement
            public void say() {
                System.out.println("Hi, this is Tom.");
            }
        });
    }
}