Java中策略模式代码分享

实现思路:
    1.定义一个策略接口
	  为接口编写多种不同的策略实现类
	2.编写主实现类
	   并为主方法中定义参数为策略
	3.当我们使用时,传入相应的策略方法
	  即可实现不同的效果

策略模式的要点:
     利用多态的特性
	 参数中使用策略接口，使用时传入具体的实现类
	 采用这种模式,达到不同的运行效果
	 其本质是多态的一种表现形式

策略模式的示例分享

public interface Strategy{
    public int calculate(int a, int b);
}

public class AddStrategy implements Strategy{
    public int calculate(int a, int b){
        return a + b;
    }
}

public class DivideStrategy implements Strategy{
    public int calculate(int a, int b){
        return a / b;
    }
}

public class MultiplyStrategy implements Strategy{
    public int calculate(int a, int b){
        return a * b;
    }
}

public class SubtractStrategy implements Strategy{
    public int calculate(int a, int b){
        return a - b;
    }
}

public class Environment{
    private Strategy strategy;
    public Environment(Strategy strategy){
        this.strategy = strategy;
    }
    public Strategy getStrategy(){
        return strategy;
    }
    public void setStrategy(Strategy strategy){
        this.strategy = strategy;
    }
    public int calculate(int a ,int b){
        return strategy.calculate(a , b);
    }
}

public class Client{
    public static void main(String[] args){
        AddStrategy addStrategy = new AddStrategy();
        Environment environment = new Environment(addStrategy);
        System.out.println(environment.calculate(88, 99));
        SubtractStrategy subtractStrategy = new SubtractStrategy();
        environment.setStrategy(subtractStrategy);
        System.out.println(environment.calculate(66, 77));
        MultiplyStrategy multiplyStrategy = new MultiplyStrategy();
        environment.setStrategy(multiplyStrategy);
        System.out.println(environment.calculate(66, 77));
        DivideStrategy divideStrategy = new DivideStrategy();
        environment.setStrategy(divideStrategy);
        System.out.println(environment.calculate(88, 99));
    }
}