软件设计23|策略模式
一、Java版本
（1）效果如下：
（2）类图如下：
（3）工程目录如下：
（4）代码如下：
AirplaneStrategy.java
1 package strategy; 2 3 public class AirplaneStrategy implements TravelStrategy { 4 5 @Override 6 public void travelMethod() { 7 // TODO Auto-generated method stub 8 System.out.println("乘坐飞机旅行"); 9 } 10 11 }
BicycleTravelStrategy.java
1 package strategy; 2 3 public class BicycleTravelStrategy implements TravelStrategy { 4 5 @Override 6 public void travelMethod() { 7 // TODO Auto-generated method stub 8 System.out.println("自行车游"); 9 } 10 11 }
Client.java
1 package strategy; 2 3 public class Client { 4 5 public static void main(String[] args) { 6 // TODO Auto-generated method stub 7 System.out.println("************"); 8 Person person=new Person(new AirplaneStrategy()); 9 System.out.print("person:"); 10 person.travelMethod(); 11 System.out.println("************"); 12 Person person1=new Person(new TrainStrategy()); 13 person1.travelMethod(); 14 System.out.print("person1:"); 15 System.out.println("************"); 16 Person person2=new Person(new BicycleTravelStrategy()); 17 person2.travelMethod(); 18 System.out.print("person2:"); 19 } 20 21 }
Person.java
1 package strategy; 2 3 public class Person { 4 private TravelStrategy travelstrategy; 5 6 public Person(TravelStrategy travelstrategy) { 7 this.travelstrategy = travelstrategy; 8 } 9 10 public void travelMethod() { 11 travelstrategy.travelMethod(); 12 } 13 }
TrainStrategy.java
1 package strategy; 2 3 public class TrainStrategy implements TravelStrategy { 4 5 @Override 6 public void travelMethod() { 7 // TODO Auto-generated method stub 8 System.out.println("乘火车旅行"); 9 } 10 11 }
TravelStrategy.java
1 package strategy; 2 3 public interface TravelStrategy { 4 public void travelMethod(); 5 }
（5）参考链接：Java设计模式（四）策略模式
二、C++版本
（1）效果如下：
（2）类图如下：
（3）代码如下：
1 #include<iostream> 2 using namespace std; 3 4 class TravelStrategy 5 { 6 public: 7 virtual void travelMethod() = 0; 8 }; 9 10 class Person 11 { 12 public: 13 Person(TravelStrategy* t) { 14 trainstrategy = t; 15 } 16 17 void travelMethod() { 18 if (nullptr != trainstrategy) 19 trainstrategy->travelMethod(); 20 } 21 22 private: 23 TravelStrategy* trainstrategy = nullptr; 24 }; 25 26 // 飞机 27 class AirplaneStrategy : public TravelStrategy 28 { 29 public: 30 void travelMethod() { 31 std::cout << "乘坐飞机旅行" << std::endl; 32 } 33 }; 34 35 // 火车 36 class TrainStrategy : public TravelStrategy 37 { 38 public: 39 void travelMethod() { 40 std::cout << "乘火车旅行" << std::endl; 41 } 42 }; 43 44 // 自行车 45 class BicycleTravelStrategy : public TravelStrategy 46 { 47 public: 48 void travelMethod() { 49 std::cout << "自行车游" << std::endl; 50 } 51 }; 52 53 int main() 54 { 55 TravelStrategy* air = new AirplaneStrategy(); 56 TravelStrategy* train = new TrainStrategy(); 57 TravelStrategy* bicycle = new BicycleTravelStrategy(); 58 59 Person* person = new Person(air); 60 Person* person1 = new Person(train); 61 Person* person2 = new Person(bicycle); 62 63 cout << "************" << endl; 64 cout << "person:"; 65 person->travelMethod(); 66 cout << "************" << endl; 67 cout << "person1:"; 68 person1->travelMethod(); 69 cout << "************" << endl; 70 cout << "person2:"; 71 person2->travelMethod(); 72 73 return 0; 74 }
（4）参考链接：C++ 策略模式 - 来一场说走就走的旅行
