桥接模式（一）

用桥接模式实现在路上开车这个问题，其中，车可以是car或bus，路可以是水泥路或沥青路。

1. 类图

 

 

2.源代码

//Road.java
package test9;
public abstract class Road {
    protected Vehicle vehicle;
    public void setVehicle(Vehicle ve) {
        this.vehicle=ve;
    }
    public abstract void drive();
}
//Shuini.java
package test9;
public class Shuini extends Road{
    public void drive() {
        vehicle.run();
        System.out.println("行驶在水泥路");
    }
}
//Liqing.java
package test9;
public class Liqing extends Road{
    public void drive() {
        vehicle.run();
        System.out.println("行驶在沥青路");
    }
}
//Vehicle.java
package test9;
public interface Vehicle {
    public void run();
}
//Bus.java
package test9;
public class Bus implements Vehicle{
    @Override
    public void run() {
        System.out.print("Bus");    
    }
}
//Car.java
package test9;
public class Car implements Vehicle{
    @Override
    public void run() {
        System.out.print("Car");    
    }
}
//Main.java
package test9;
import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        Vehicle vehicle = null;
        Road road = null;
        System.out.println("请选择：1、Car/水泥路  2、Car/沥青路  3、Bus/水泥路  4、Bus/沥青路");
        Scanner input=new Scanner(System.in);
        int i=input.nextInt();
        if(i==1) {
            vehicle=(Vehicle)new Car();
            road=(Road)new Shuini();
        }else if(i==2) {
            vehicle=(Vehicle)new Car();
            road=(Road)new Liqing();
        }else if(i==3){
            vehicle=(Vehicle)new Bus();
            road=(Road)new Shuini();
        }else if(i==4) {
            vehicle=(Vehicle)new Bus();
            road=(Road)new Liqing();
        }else {
            System.out.println("输入无效！");
        }
        road.setVehicle(vehicle);
        road.drive();
    }
}