手写一个装饰器模式融合责任链模式的组合模式

public class Param {
    double number;

    public double getNumber() {
        return number;
    }

    public void setNumber(double number) {
        this.number = number;
    }
}

public class Result {

    private double result;

    public double getResult() {
        return result;
    }

    public void setResult(double result) {
        this.result = result;
    }
}

public abstract class FeeCalcHandler {

    protected FeeCalcHandler nextHandler;

    abstract Result calc(Param param);
}

public class NewFeeCalcHandler extends FeeCalcHandler{

    @Override
    Result calc(Param param) {
        Result result = new Result();
        if(nextHandler != null){
            result= nextHandler.calc(param);
        }
        result.setResult(param.getNumber() + 1);
        return result;
    }
}

public class VIPFeeCalcHandler extends FeeCalcHandler{
    @Override
    Result calc(Param param) {
        Result result = new Result();
        if(nextHandler != null){
            result = nextHandler.calc(param);
        }
        result.setResult(param.getNumber() * 10);
        return result;
    }
}

public class InitFeeCalcHandler {
    private  HandlerNode handlerNode = new HandlerNode();

    InitFeeCalcHandler addLeft(FeeCalcHandler handler){
        handlerNode.addLeft(new HandlerNode(handler));
        return this;
    }

    InitFeeCalcHandler addRight(FeeCalcHandler handler){
        handlerNode.addRight(new HandlerNode(handler));
        return this;
    }


    public Result calc(Param param) {
        return handlerNode.handler.calc(param);
    }

    public void getAll(Consumer<HandlerNode> consumer){
        HandlerNode temp = handlerNode;
        while (temp != null){
            consumer.accept(temp);
            temp = temp.next;
        }
    }
    class HandlerNode{

        HandlerNode next;

        FeeCalcHandler handler;

        public HandlerNode(){}

        private HandlerNode(FeeCalcHandler leaveHandler){
            this.handler = leaveHandler;
        }

        public void addRight(HandlerNode node){
            if(handlerNode.handler == null){
                handlerNode = node;
                return;
            }
            HandlerNode tailNode = getTail(handlerNode);
            tailNode.handler.nextHandler= node.handler;
            tailNode.next = node;
        }

        public HandlerNode getTail(HandlerNode node){
            if(node.next == null || node.next.handler == null){
                return node;
            }
            return getTail(node.next);
        }

        public void addLeft(HandlerNode node){
            if(handlerNode.handler == null){
                handlerNode = node;
                return;
            }
            HandlerNode temp = handlerNode;
            handlerNode = node;
            handlerNode.next = temp;
            handlerNode.handler.nextHandler = temp.handler;
        }
    }
}

public class HandlerV2Test {
    public static void main(String[] args) {
        Param param = new Param();
        param.setNumber(100);
        InitFeeCalcHandler initFeeCalcHandler = new InitFeeCalcHandler();
        initFeeCalcHandler
                .addRight(new NewFeeCalcHandler())
                .addRight(new VIPFeeCalcHandler());
        Result result = initFeeCalcHandler.calc(param);
        System.out.println(result.getResult());
    }
}

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