Java设计模式之桥接模式(Bridge)实践

       桥接模式定义:将抽象部分与实现部分分离，使它们都可以独立的变化。
       实现系统可能有多个角度分类，每一种角度都可能变化。此时可以使用桥接模式。

以下代码演示桥接模式简单的实际运用:

定义一个接口Travel:
package com.ldl.cn.BridgeModel;

public interface Travel {
    public void travelStyle();
}

定义一个抽象类People:
package com.ldl.cn.BridgeModel;

public abstract class People {
    
    protected Travel travel;

    public People(Travel travel) {
        super();
        this.travel = travel;
    }
    public abstract void relax();
}

分别定义类TravelByAircraft、TravelByTrain实现Travel接口:
package com.ldl.cn.BridgeModel;

public class TravelByAircraft implements Travel{

    @Override
    public void travelStyle() {
        System.out.println("Travel by aircraft.");
    }
}

package com.ldl.cn.BridgeModel;

public class TravelByTrain implements Travel{

    @Override
    public void travelStyle() {
        System.out.println("Travel by train.");
    }
}

定义类TravelMan继承People:
package com.ldl.cn.BridgeModel;

public class TravelMan extends People{

    public TravelMan(Travel travel) {
        super(travel);
    }

    @Override
    public void relax() {
        travel.travelStyle();
    }
}

编写测试类:
package com.ldl.cn.BridgeModel;

public class TestBridgePattern {

    public static void main(String[] args) {
        People people_train = new TravelMan(new TravelByTrain());
        People people_aircraft = new TravelMan(new TravelByAircraft());
        people_train.relax();
        people_aircraft.relax();
    }
}

运行结果:
Travel by train.
Travel by aircraft.