策略模式（一）

旅游的出行方式有乘坐飞机旅行、乘火车旅行和自行车游，不同的旅游方式有不同的实现过程，客户可以根据自己的需要选择一种合适的旅行方式。

//Person.java
package test23;
public class Person {
    //聚合策略类对象
    private TravelStrategy strategy;
    public void setStrategy(TravelStrategy strategy) {
        this.strategy=strategy;
    }
    public void travel() {
        strategy.travel();
    }
}
//TravelStrategy.java
package test23;
public interface TravelStrategy {
    public void travel();
}
//AirplaneStrategy.java
package test23;
public class AirplaneStrategy implements TravelStrategy{

    public void travel() {
        System.out.println("乘坐飞机旅行");
    }
    
}
//BicycleStrategy.java
package test23;
public class BicycleStrategy implements TravelStrategy{

    public void travel() {
        System.out.println("自行车游");
    }
    
}
//TrainStrategy.java
package test23;
public class TrainStrategy implements TravelStrategy{

    public void travel() {
        System.out.println("乘火车旅行");
    }
    
}
//Client.java
package test23;
import java.util.Scanner;
public class Client {
    public static void main(String[] args) {
        Person p = new Person();
        System.out.println("请选择出行方式：1、飞机  2、火车  3、自行车");
        Scanner input=new Scanner(System.in);
        int i=input.nextInt();
        if(i==1) {
            p.setStrategy(new AirplaneStrategy());
        }else if(i==2) {
            p.setStrategy(new TrainStrategy());
        }else if(i==3) {
            p.setStrategy(new BicycleStrategy());
        }
        p.travel();
    }
}