1.策略模式结构图:

2.示例代码:
首先是一个策略类的接口或者抽象类,这里创建的是接口:
public interface Strategy {
    void play();
}
接着创建具体的策略类,封装不同的实现算法:
public class StrategyA implements Strategy{
    @Override
    public void play() {
        System.out.println("这是策略A=========");
    }
}
public class StrategyB implements Strategy{
    @Override
    public void play() {
        System.out.println("这是策略B=========");
    }
}
接着创建容器对象,让它持有策略的实例:
public class StrategyContext {
    private Strategy strategy;
    public StrategyContext(Strategy strategy) {
        this.strategy = strategy;
    }
    public void doPlay() {
        strategy.play();
    }
}
测试:
public static void main(String[] args) {
        StrategyContext context = new StrategyContext(new StrategyA());
        context.doPlay();
        StrategyContext context1 = new StrategyContext(new StrategyB());
        context1.doPlay();
}
原文:https://www.cnblogs.com/wqlken/p/14642908.html