設計模式學習程式碼

裝飾模式

public class DecoratorPattern {
    public static void main(String[] args) {
        ConcreteComponent c = new ConcreteComponent();
        ConcreteDecoratorA a = new ConcreteDecoratorA();
        ConcreteDecoratorB b = new ConcreteDecoratorB();
        a.SetComponent(c);
        b.
 
SetComponent(a);
        b.Operation();
    }
}

abstract class Component {

    public abstract  void Operation();
}

class ConcreteComponent extends Component {

    @Override
    public void Operation() {
        System.out.println("具體物件的操作類");
    }
}

abstract class Decorator extends  Component
 
 {

    protected  Component component;

    public void SetComponent(Component component) {
        this.component = component;
    }

    @Override
    public  void Operation(){
        if (component!=null){
            component.Operation();
        }
    }
}

class ConcreteDecoratorA extends Decorator
 
 {

    private String addedState;
    @Override
    public  void Operation(){
        super.Operation();
        addedState = "New State";
        System.out.println("具體裝飾物件A的操作類");
    }

}

class ConcreteDecoratorB extends Decorator {

    @Override
    public  void Operation(){
        super.Operation();
        AddedBehavior();
        System.out.println("具體裝飾物件B的操作類");
    }
    private void AddedBehavior(){

    }
}

策略模式

public class StrategyPattern {
    public static void main(String[] args) {
        Context context;

        context = new Context(new StrategyA());
        context.context();

        context = new Context(new StrategyB());
        context.context();

        context = new Context(new StrategyC());
        context.context();
    }
}


//抽象演算法類
abstract class Strategy {

    //演算法方法
    public abstract void  algorithm();
}

//具體演算法A
class StrategyA extends  Strategy {

    @Override
    public void algorithm() {
        System.out.println("演算法A實現");
    }
}

//具體演算法B
class StrategyB extends  Strategy {

    @Override
    public void algorithm() {
        System.out.println("演算法B實現");
    }
}

//具體演算法B
class StrategyC extends  Strategy {

    @Override
    public void algorithm() {
        System.out.println("演算法C實現");
    }
}


class Context {

    private  Strategy strategy ;

    // 策略選擇
    public Context(Strategy strategy) {
        this.strategy = strategy;
    }

    public void context(){
        strategy.algorithm();
    }
}