행위패턴 : Mediator 패턴

분류 : 행위패턴(Behavioral Patterns)

정의 :

여러개의 객체와 상호작용하는 것을 캡슐화하는 객체. 객체간의 결합도를 느슨하게 만듬.

용도 :

Mediator - Colleague 객체간의 통신을 위한 인터페이스를 정의함.

ConcreteMediator - Mediator 인터페이스를 구현하고 Colleague 객체간의 통신을 관리함. 모든 Colleagues와 Colleagues의 내부 통신 방법을 알고 있음.

ConcreteColleague - Colleagues의 Mediator를 통해서 각 Colleagues간에 통신을 함.

소스

import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
 
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
 
//Colleague interface
interface Command {
    void execute();
}


//Abstract Mediator
interface IMediator {
  public void book();
  public void view();
  public void search();
  public void registerView(BtnView v);
  public void registerSearch(BtnSearch s);
  public void registerBook(BtnBook b);
  public void registerDisplay(LblDisplay d);
}


//Concrete mediator
class Mediator implements IMediator {

  BtnView btnView;
  BtnSearch btnSearch;
  BtnBook btnBook;
  LblDisplay show;

  //....
  public void registerView(BtnView v) {
      btnView = v;
  }

  public void registerSearch(BtnSearch s) {
      btnSearch = s;
  }

  public void registerBook(BtnBook b) {
      btnBook = b;
  }

  public void registerDisplay(LblDisplay d) {
      show = d;
  }

  public void book() {
      btnBook.setEnabled(false);
      btnView.setEnabled(true);
      btnSearch.setEnabled(true);
      show.setText("booking...");
  }

  public void view() {
      btnView.setEnabled(false);
      btnSearch.setEnabled(true);
      btnBook.setEnabled(true);
      show.setText("viewing...");
  }

  public void search() {
      btnSearch.setEnabled(false);
      btnView.setEnabled(true);
      btnBook.setEnabled(true);
      show.setText("searching...");
  }

}


import javax.swing.JButton;
import java.awt.event.ActionListener;

import BehavioralPatterns.command.Command;

//A concrete colleague
public class BtnView extends JButton implements Command {

	IMediator med;
	 
    BtnView(ActionListener al, IMediator m) {
        super("View");
        addActionListener(al);
        med = m;
        med.registerView(this);
    }
 
    public void execute() {
        med.view();
    }
 
}


import javax.swing.JButton;
import java.awt.event.ActionListener;

import BehavioralPatterns.command.Command;

//A concrete colleague
public class BtnSearch extends JButton implements Command {

	IMediator med;
	 
    BtnSearch(ActionListener al, IMediator m) {
        super("Search");
        addActionListener(al);
        med = m;
        med.registerSearch(this);
    }
 
    public void execute() {
        med.search();
    }

}


import javax.swing.JButton;
import java.awt.event.ActionListener;

import BehavioralPatterns.command.Command;

//A concrete colleague
public class BtnBook extends JButton implements Command {


    IMediator med;
 
    BtnBook(ActionListener al, IMediator m) {
        super("Book");
        addActionListener(al);
        med = m;
        med.registerBook(this);
    }
 
    public void execute() {
        med.book();
    }

}


import java.awt.Font;
import javax.swing.JLabel;

public class LblDisplay extends JLabel {
	IMediator med;
	 
    LblDisplay(IMediator m) {
        super("Just start...");
        med = m;
        med.registerDisplay(this);
        setFont(new Font("Arial", Font.BOLD, 24));
    }
}


import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JFrame;
import javax.swing.JPanel;

public class MediatorDemo extends JFrame implements ActionListener {

	IMediator med = new Mediator();
	 
    MediatorDemo() {
        JPanel p = new JPanel();
        p.add(new BtnView(this, med));
        p.add(new BtnBook(this, med));
        p.add(new BtnSearch(this, med));
        getContentPane().add(new LblDisplay(med), "North");
        getContentPane().add(p, "South");
        setSize(400, 200);
        setVisible(true);
    }
 
    public void actionPerformed(ActionEvent ae) {
        Command comd = (Command) ae.getSource();
        comd.execute();
    }
 
    public static void main(String[] args) {
        new MediatorDemo();
    }

}

참고자료

http://en.wikipedia.org/wiki/Mediator_pattern