優(yōu)雅解決大量if判斷

一：前言

大家都在項(xiàng)目上遇到大量的if判斷影響代碼的可讀性和復(fù)雜度睬罗，對(duì)于后期不好維護(hù)等問(wèn)題。下面如何解決大量if條件讓代碼看起來(lái)很優(yōu)雅

二：項(xiàng)目需求

我在項(xiàng)目里有個(gè)集成支付接口旭斥，比如支付寶容达、微信、銀聯(lián)等支付接口垂券。在前端入?yún)⒌闹Ц额愋突ㄑ危蠖烁鶕?jù)支付類型調(diào)用封裝好的支付接口，這樣一來(lái)代碼就會(huì)存在難以維護(hù)的if校驗(yàn)菇爪。

三:引入策略設(shè)計(jì)模式解決if判斷

項(xiàng)目中的實(shí)例

1.創(chuàng)建一個(gè)interface接口

public interface RefundStrategy {

    /**
     *
     * @param tradeNo 交易流水號(hào)
     * @param refundNo 退款單號(hào)
     * @param totalAmount 訂單總金額
     * @param refundAmount 退款金額
     * @param refundReason 退款原因
     * @return 退款結(jié)果集 {@link PayResult}
     */
    PayResult doPayRefund(String tradeNo, String refundNo, String orderNo,String thirdpartPayNo, String totalAmount, String refundAmount, String refundReason);
}

2.在Ali實(shí)現(xiàn)類實(shí)現(xiàn)該接口

Data
@Component
public class AliPayRefundStrategy implements RefundStrategy {


    private static YueProperties properties;

    private static CommonUtil commonUtil;


    private static void setCommonUtilFactory(CommonUtil util) {
        if (AliPayRefundStrategy.commonUtil == null) {
            AliPayRefundStrategy.commonUtil = util;
        }
    }

    @Resource
    public void setCommonUtil(CommonUtil util) {
        AliPayRefundStrategy.setCommonUtilFactory(util);
    }



    private static void setPropertiesFactory(YueProperties yueProperties) {
        if (AliPayRefundStrategy.properties == null) {
            AliPayRefundStrategy.properties = yueProperties;
        }
    }

    @Resource
    public void setProperties(YueProperties yueProperties) {
        AliPayRefundStrategy.setPropertiesFactory(yueProperties);
    }

    @Override
    public PayResult doPayRefund(String tradeNo, String refundNo,String orderNo,String thirdpartPayNo, String totalAmount, String refundAmount, String refundReason) {

        YuePay yuepay = new YueAliPay(properties.getPay().getAlipay().getAppId(), properties.getPay().getAlipay().getPublicKey(),
                properties.getPay().getAlipay().getPrivateKey());
        String response = yuepay.refund(tradeNo, refundNo, totalAmount, refundAmount, refundReason);
        PayResult payResult = commonUtil.readValue(response, PayResult.class);
        //獲取退款交易流水號(hào)
        @SuppressWarnings("unchecked")
        Map<String, String> map = commonUtil.readValue(payResult.getParams(), Map.class);
        payResult.setTradeNo(map.get("trade_no"));
        return payResult;
    }

3.創(chuàng)建策略工廠

public class RefundStrategyFactory {

    private static  Map<Integer, RefundStrategy>  originalMap= new HashMap<>();
    private static  Map<Integer, RefundStrategy> unOriginalMap = new HashMap<>();
    //原路退款
    static {
        originalMap.put(ReceptionPaymentDict.RefundPayType.WXPAY_CARD.getValue(), new WxPayRefundStrategy());
        originalMap.put(ReceptionPaymentDict.RefundPayType.WXPAY_H5.getValue(), new WxPayRefundStrategy());
        originalMap.put(ReceptionPaymentDict.RefundPayType.ALIPAY.getValue(), new AliPayRefundStrategy());
        originalMap.put(ReceptionPaymentDict.RefundPayType.ALIPAY_H5.getValue(), new AliPayRefundStrategy());
        originalMap.put(ReceptionPaymentDict.RefundPayType.JHPAY.getValue(), new JuhePayRefundStrategy());
        originalMap.put(ReceptionPaymentDict.RefundPayType.WXPAY_GZH.getValue(), new WxPayRefundStrategy());
        originalMap.put(ReceptionPaymentDict.PayType.UNION_PAY.getValue(), new UnionPayRefundStrategy());
        originalMap.put(ReceptionPaymentDict.PayType.BEST_PAY.getValue(), new BestPayRefundStrategy());

    }
    //手工退款
    static {
        unOriginalMap.put(ReceptionPaymentDict.RefundPayType.JHPAY.getValue(), new OtherPayRefundStrategy());
        unOriginalMap.put(ReceptionPaymentDict.PayType.CASH.getValue(), new OtherPayRefundStrategy());
        unOriginalMap.put(ReceptionPaymentDict.RefundPayType.COMPANY_TRANSFER.getValue(), new OtherPayRefundStrategy());
        unOriginalMap.put(ReceptionPaymentDict.RefundPayType.SZ_ICBC.getValue(), new OtherPayRefundStrategy());
        unOriginalMap.put(ReceptionPaymentDict.RefundPayType.OTHER.getValue(), new OtherPayRefundStrategy());
        unOriginalMap.put(ReceptionPaymentDict.RefundPayType.ALIPAY.getValue(), new OtherPayRefundStrategy());
        unOriginalMap.put(ReceptionPaymentDict.RefundPayType.WXPAY_CARD.getValue(), new OtherPayRefundStrategy());
        unOriginalMap.put(ReceptionPaymentDict.RefundPayType.NB_ICBC.getValue(), new OtherPayRefundStrategy());
        unOriginalMap.put(ReceptionPaymentDict.RefundPayType.CQ_ICBC.getValue(), new OtherPayRefundStrategy());
        unOriginalMap.put(ReceptionPaymentDict.RefundPayType.GZ_ICBC.getValue(), new OtherPayRefundStrategy());
        unOriginalMap.put(ReceptionPaymentDict.PayType.POS.getValue(), new OtherPayRefundStrategy());
        unOriginalMap.put(ReceptionPaymentDict.PayType.BEST_PAY.getValue(), new OtherPayRefundStrategy());
        unOriginalMap.put(ReceptionPaymentDict.RefundPayType.WXPAY_CARD.getValue(), new OtherPayRefundStrategy());
        unOriginalMap.put(ReceptionPaymentDict.RefundPayType.WXPAY_H5.getValue(), new OtherPayRefundStrategy());
        unOriginalMap.put(ReceptionPaymentDict.RefundPayType.ALIPAY.getValue(), new OtherPayRefundStrategy());
        unOriginalMap.put(ReceptionPaymentDict.RefundPayType.ALIPAY_H5.getValue(), new OtherPayRefundStrategy());
        unOriginalMap.put(ReceptionPaymentDict.RefundPayType.JHPAY.getValue(), new OtherPayRefundStrategy());
        unOriginalMap.put(ReceptionPaymentDict.RefundPayType.WXPAY_GZH.getValue(), new OtherPayRefundStrategy());
        unOriginalMap.put(ReceptionPaymentDict.PayType.UNION_PAY.getValue(), new OtherPayRefundStrategy());

    }

    private RefundStrategyFactory() {

    }
   public static RefundStrategy getPayRefundStrategy(Integer key, Boolean original) {
        if (original) {
            return  originalMap.get(key);
        }
       return  unOriginalMap.get(key);

    }

}

4.創(chuàng)建上下文請(qǐng)求

public class PayRefundContext {

    @Resource
    private RefundStrategy payRefundStrategy;

    public PayRefundContext(RefundStrategy payRefundStrategy) {
        this.payRefundStrategy = payRefundStrategy;
    }

    public PayResult executePayRefundStrategy(String tradeNo, String refundNo,String orderNo, String thirdpartPayNo, String totalAmount, String refundAmount, String refundReason) {
       return payRefundStrategy.doPayRefund(tradeNo, refundNo, orderNo, thirdpartPayNo, totalAmount, refundAmount, refundReason);
    }

}

5.測(cè)試類

  @Test
    public void executePayRefundStrategy() {

        PayRefundContext payRefundContext = new PayRefundContext(RefundStrategyFactory.getPayRefundStrategy(18, true));
        PayResult payResult = payRefundContext.executePayRefundStrategy(
                "1111","1111","1111", "1111","111","111","1111"
        );
    }