1. Observer Pattern

よくある場所eventlistenerでこのモードを使用

2.テスト項目

package com.company.design.observer;

public interface IButtonListener {

    void clickEvnet(String event);
}

package com.company.design.observer;

public class Button {

    private String name;
    private IButtonListener buttonListener;

    public Button(String name) {
        this.name = name;
    }

    public void click(String message) {
        buttonListener.clickEvnet(message);
    }

    public void addListener(IButtonListener iButtonListener) {
        this.buttonListener = iButtonListener;
    }
}

package com.company.design;

import com.company.design.observer.Button;
import com.company.design.observer.IButtonListener;

public class Main {

    public static void main(String[] args) {
        Button button = new Button("버튼");
        button.addListener(new IButtonListener() {
            @Override
            public void clickEvnet(String event) {
                System.out.println(event);
            }
        });
        button.click("메시지 전달 : click 1");
        button.click("메시지 전달 : click 2");
        button.click("메시지 전달 : click 3");
        button.click("메시지 전달 : click 4");
    }
}