设计模式-策略模式

结构图：

实现：

abstract public class Strategy {
    public void algrithmInterface()
    {    
    }
}

public class StrategyA extends Strategy{

    @Override
    public void algrithmInterface() {
        super.algrithmInterface();
        System.out.println("算法A的实现");
    }
    

}

public class StrategyB extends Strategy{

    @Override
    public void algrithmInterface() {
        super.algrithmInterface();
        System.out.println("算法B的实现");
    }
    

}

public class Context {

    private Strategy strategy;

    public Context(Strategy strategy) {
        super();
        this.strategy = strategy;
    }
    
    public void contextInterface()
    {
        strategy.algrithmInterface();
    }
    
    public void setStrategy(Strategy s)
    {
        this.strategy = s;
    }
}

public class Client {
    public static void main(String[] args)
    {
        Context context = new Context(new StrategyA());
        context.contextInterface();
        
        context.setStrategy(new StrategyB());
        context.contextInterface();
    }
}

应用常用：
该模式封装了一系列算法，让它们而已相互替换，而不会影响到客户端的变化。