跑腿小程序配送费到底怎么定？低价真的能带来订单吗？

配送费 = 基础价 + (距离 × 单价) + 高峰附加费 + 特殊附加费

CREATE TABLE delivery_fee_rule (
    id BIGINT PRIMARY KEY AUTO_INCREMENT,
    base_price DECIMAL(10,2),        -- 起步价
    base_distance DECIMAL(5,2),      -- 起步公里
    per_km_price DECIMAL(10,2),      -- 每公里单价
    peak_extra DECIMAL(10,2),        -- 高峰附加费
    weather_extra DECIMAL(10,2),     -- 天气附加费
    status TINYINT DEFAULT 1
);

public BigDecimal calculateDeliveryFee(Order order, DeliveryFeeRule rule) {

    BigDecimal fee = rule.getBasePrice();

    // 计算超出公里数
    if (order.getDistance().compareTo(rule.getBaseDistance()) > 0) {

        BigDecimal extraDistance = order.getDistance()
                .subtract(rule.getBaseDistance());

        BigDecimal distanceFee = extraDistance
                .multiply(rule.getPerKmPrice());

        fee = fee.add(distanceFee);
    }

    // 高峰时段加价
    if (isPeakTime()) {
        fee = fee.add(rule.getPeakExtra());
    }

    // 恶劣天气加价
    if (isBadWeather()) {
        fee = fee.add(rule.getWeatherExtra());
    }

    return fee;
}

public BigDecimal calculateByTier(BigDecimal distance) {

    if (distance.compareTo(new BigDecimal("3")) <= 0) {
        return new BigDecimal("5");
    }

    if (distance.compareTo(new BigDecimal("5")) <= 0) {
        return new BigDecimal("8");
    }

    if (distance.compareTo(new BigDecimal("8")) <= 0) {
        return new BigDecimal("12");
    }

    return new BigDecimal("15");
}

String key = "order_lock:" + userId;

Boolean success = redisTemplate.opsForValue()
        .setIfAbsent(key, "1", 5, TimeUnit.SECONDS);

if (!success) {
    throw new RuntimeException("请勿重复提交订单");
}