如何实现Java监听器详解

package demo.listener;


public interface DeveloperListener {
    
    void work(Event event);

    
    void study(Event event);
}

package demo.listener;

import java.util.Optional;
import java.util.function.Supplier;


public class Developer {
    private DeveloperListener developerListener;


    
    public void reGISterListener(DeveloperListener developerListener) {
        this.developerListener = developerListener;
    }

    
    public void work() {
        if (developerListener != null) {
            this.developerListener.work(new Event(this));
        }
        System.out.println("developer work");
    }


    
    public void study(){
        if (developerListener != null){
            this.developerListener.study(new Event(this));
            System.out.println("developer study");
        }
    }
}

package demo.listener;


public class Event {
    
    private Developer developer;

    public Event(Developer developer) {
        this.developer = developer;
    }

    public Event() {
    }

    public Developer getDeveloper() {
        return developer;
    }

    public void setDeveloper(Developer developer) {
        this.developer = developer;
    }
}

package demo.listener;


public class DeveloperListenerImpl implements DeveloperListener {
    @Override
    public void work(Event event) {
        Developer developer = event.getDeveloper();
        System.out.println("work developer impl listener");

    }

    @Override
    public void study(Event event) {
        Developer developer = event.getDeveloper();
        System.out.println("study developer impl listener");

    }
}

package demo.listener;


public class ListenerTest {
    public static void main(String[] args) {
        Developer developer = new Developer();
        developer.registerListener(new DeveloperListenerImpl());
        developer.study();
        developer.work();
    }
}