策略模式demo

/** StrategyContext. */
public class StrategyContext {
    
    private Strategy strategy;
    
    // 传入的是Strategy的实现类的实例
    public Context(Strategy strategy){
        this.strategy = strategy;
    }
   
    public void contextMethod(){  
        // 这是关键
        strategy.strategyMethod();
    }  
}

/** 策略接口. */
public interface Strategy {
    
    public void strategyMethod();
}

/** 策略A. */
public class StrategyA implements Strategy {

    @Override
    public void strategyMethod() {
        //业务A
    }
}

public class StrategyB implements Strategy {

    @Override
    public void strategyMethod() {
        //业务B
    }
}

public class StrategyC implements Strategy {

    @Override
    public void strategyMethod() {
        //业务C
    }
}