策略模式

Posted 2020-09-06

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用户的角度：只需要知道具体的Context,并知道具体的策略类。

实现者的角度：拥有具体的策略类,封装了具体的算法或行为,并抽象一个公共的算法接口，包含在一个Context上下文中。

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package com.stategy;

/**
 * 上下文
 * @author 黄二狗
 *
 */
public class Context {
   private Strategy strategy;
   public Context(Strategy strategy)
   {
       this.strategy=strategy;
   }
   
   public void contextInterface()
   {
       strategy.Algorithmlnterface();
   }
}

 

package com.stategy;

public interface Strategy {
   void Algorithmlnterface();
}

package com.stategy;

public class ConcreteStrategyA implements Strategy{

    @Override
    public void Algorithmlnterface() {
        System.out.println("具体的策略A");
        
    }

}

package com.stategy;

public class ConcreteStrategyB implements Strategy{

    @Override
    public void Algorithmlnterface() {
        System.out.println("具体的策略B");
        
    }

}

package com.stategy;

public class ConcreteStrategyC implements Strategy{

    @Override
    public void Algorithmlnterface() {
        System.out.println("具体的策略C");
        
    }

}

package com.stategy;

/**
 * 用户需要知道具体的策略和策略接口还有上下文及其上下文的方法
 * @author 黄二狗
 *
 */
public class Client {
   public static void main(String[] args) {
      Strategy strategy=new ConcreteStrategyA();
      Context context=new Context(strategy);
      context.contextInterface();
}
}