设计模式（策略模式）

策略模式很简单，类似于C里维护一个函数指针，只是将具体策略抽象出来并维护。

代码如下：

• Strategy

public interface Strategy {
    public void doMethod();
}

• ConcreteStrategy

public class ConcreteStrategy implements Strategy {

    @Override
    public void doMethod() {
        System.out.println("ConcreteStrategy method");
    }
}

• Context

public class Context {
    private Strategy strategy;
    
    public Context(Strategy strategy){
        this.strategy = strategy;
    }
    
    public void doMethod(){
        strategy.doMethod();
    }
}

• APP 测试类

public class App {

    public static void main(String[] args) {
        Context context = new Context(new ConcreteStrategy());
        context.doMethod();
    }
}