桥接模式

1、简介

使抽象和实现进行解耦，使得二者可以独立变化。通过抽象化和实现化之间的桥接结构实现解耦。

核心代码: 抽象类依赖实现类

一个简单的例子就是轮渡，轮渡公司可以过江，你也要过江，但你又不会游泳，这时就需要有个具体干事的东西，让轮渡公司去选择，你是要乘快艇、小船、还是游艇过江。

这里的游艇就相当于一个桥梁，抽象类和实现类都通过游艇进行关联，由游客选择游艇类型、选择游艇级别和价位。然后游艇由父类游艇管理，游客仅供使用[调用].

2、实现

/**
 * 轮船公司接口
 * @author Administrator
 */
public abstract class ShippingCompany {
	
	protected Shipping shipping;
	
	public ShippingCompany(Shipping shipping) {
		this.shipping = shipping;
	}
	
	public abstract void travel();
}

/**
 * 轮船接口
 * @author Administrator
 */
public interface Shipping {

	public void travelRiver(int level, double money);
}

/**
 * 邮轮类
 * @author Administrator
 */
public class Cruise implements Shipping{

	@Override
	public void travelRiver(int level, double money) {
		System.out.println();
		System.out.println(String.format("I'm Cruise level: %d, cost: %f", level, money));
	}
}

/**
 * 游艇类
 * @author Administrator
 */
public class SpeedBoat implements Shipping{
	
	@Override
	public void travelRiver(int level, double money) {
		System.out.println(String.format("I'm SpeedBoat level: %d, cost: %f", level, money));
	}
}

/**
*游客类
*/
public class MrLiu extends ShippingCompany{
	
	private int level;
	private double money;
	
	public MrLiu(int level, double money, Shipping shipping) {
		super(shipping);
		this.level = level;
		this.money = money;
	}
	
	
	@Override
	public void travel() {
		shipping.travelRiver(level, money);
	}
}

// Test
int level = 3;
double money = 88888888;
Shipping cruise = new Cruise();
MrLiu liu1 = new MrLiu(level, money, cruise);
Shipping speedBoat = new SpeedBoat();
MrLiu liu2 = new MrLiu(level, money, speedBoat);
liu1.travel();
liu2.travel();