设计模式

设计模式

1.单例模式
	package com.it18zhang.java37.gof;

	/**
	 * 饿汉式
	 */
	public class GargageBoxLazy {
		
		private static GargageBoxLazy instance ;
		
		public static GargageBoxLazy getInstance(){
			if(instance == null){
				System.out.println("....");
				synchronized (GargageBoxLazy.class) {
					if(instance == null){
						instance = new GargageBoxLazy();
					}
				}
			}
			return instance ;
		}
		
		private GargageBoxLazy(){
		}
	}

2.Factory
	class MesssageFactory{
		public static Message newMessage(){
			...

		}
	}

	new MessageFactory().newMessage();

3.装饰模式:
	流
	class A{
		...

		public void xx(){
			..
		}
	}

	class WrapedA extends A{
		private A a ;

		public WrapedA(A a){
			this.a = a ;
		}


		public void xx(){
			System.out.println(...);
			a.xxx()
			System.out.println(...);
		}
	}
4.Builder模式
	Message m = new Message();
	m.setA();
	m.setB();
	...
	
	class Message{
		public Message setA(){
			...
			return this ;
		}
		..


	}
	//链式编程.
	new Message().setA().setB().setC();
	

5.适配器
	class Button{
		public void addButtonListener(MouseListener l){
			this.l = l ;
		}
	}

	new Button().addButtonListener(new MouseAdater(){
		public void click(){
			...
		}
	});

	interface MouseListener{
		public void click();
		pulic void dbClick();
		...
	}

	public abstract class MouseAdater implements MouseListener{
		public void click(){}
		pulic void dbClick(){}
		...
		;
		;
		;
		;

	}