策略模式笔记

// 策略接口
public interface Strategy {
    void execute();
}
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// 具体策略类A
public class ConcreteStrategyA implements Strategy {
    @Override
    public void execute() {
        System.out.println("This is ConcreteStrategyA");
    }
}
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// 具体策略类B
public class ConcreteStrategyB implements Strategy {
    @Override
    public void execute() {
        System.out.println("This is ConcreteStrategyB");
    }
}
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// 用户类
public class Context { 
    private Strategy strategy;
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    public Context(Strategy strategy) {
        this.strategy = strategy;
    }
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    public Strategy getStrategy() {
        return strategy;
    }
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    public void setStrategy(Strategy strategy) {
        this.strategy = strategy;
    }
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    // 用户方法，执行具体赋值的策略的计算方法
    public void execute() {
        System.out.println("context execute");
        strategy.execute();
    }
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    public static void main(String[] args) {
        Context context = new Context(new ConcreteStrategyA());
        context.execute();
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        // 可以根据输入的数据等信息进行判断，设置对应的具体策略来执行
        context.setStrategy(new ConcreteStrategyB());
        context.execute();
    }
}