1、前言
1.1 商品有三个属性
周期时长、周期单位、叠加次数
1.2 商品配置阶梯
| 用量大于0GB, 流量总价30元 |
| 用量大于90GB, 流量单价0.19元/GB |
| 用量大于100GB, 流量单价0.12元/GB |
2、根据不同属性获取阶梯下金额
2.1 B商品结果
| B商品 |
| 1月 | 2月 | 3月 | 4月 | 5月 | 6月 | 7月 | 8月 | 9月 |
| 用量 | 10KB | 50KB | 90KB | 91KB | 101KB | 102KB | | | |
| >0 | 30元 | 30元 | 30元 | 30元 | 30元 | 30元 | | | |
| >90 | 0元 | 0元 | 0元 | 0.19元 | 1.9元 | 1.9元 | | | |
| >100 | 0元 | 0元 | 0元 | 0元 | 0.12元 | 0.24元 | | | |
2.1 A商品结果
| A商品 |
| 1月 | 2月 | 3月 | 4月 | 5月 | 6月 | 7月 | 8月 | 9月 |
| 用量 | 10KB | 50KB | 31KB | 10KB | 10KB | 50KB | 31KB | 10KB | |
| >0 | 30元 | 0元 | 0元 | 0元 | 30元 | 0元 | 0元 | 0元 | |
| >90 | 0元 | 0元 | 0.19元 | 1.71元 | 0元 | 0元 | 0.19元 | 1.71元 | |
| >100 | 0元 | 0元 | 0元 | 0.12元 | 0元 | 0元 | 0元 | 0.12元 | |
@Slf4j
public class FlowSegmentGoodsClearingAlgorithm {private static String flowSegmentRuleStr = "{\"flowLadderList\":" + "[" +"{\"beginLadder\":0,\"calculationType\":1,\"unit\":\"KB\",\"unitPrice\":30.0000000000}," +"{\"beginLadder\":90,\"calculationType\":0,\"unit\":\"KB\",\"unitPrice\":0.1900000000}," +"{\"beginLadder\":100,\"calculationType\":0,\"unit\":\"KB\",\"unitPrice\":0.1200000000}" +"]}";public static void main(String[] args) {Map<String, BigDecimal> quantityMap = new HashMap<>();
// quantityMap.put("2023-01", new BigDecimal("10"));
// quantityMap.put("2023-02", new BigDecimal("50"));
// quantityMap.put("2023-03", new BigDecimal("90"));
// quantityMap.put("2023-04", new BigDecimal("91"));
// quantityMap.put("2023-05", new BigDecimal("101"));
// quantityMap.put("2023-06", new BigDecimal("102"));quantityMap.put("2023-01", new BigDecimal("10"));quantityMap.put("2023-02", new BigDecimal("50"));quantityMap.put("2023-03", new BigDecimal("31"));quantityMap.put("2023-04", new BigDecimal("10"));
// quantityMap.put("2023-05", new BigDecimal("101"));
// quantityMap.put("2023-06", new BigDecimal("102"));FlowSegmentRule flowSegmentRule = JSON.parseObject(flowSegmentRuleStr, FlowSegmentRule.class);List<FlowLadder> flowLadderList = flowSegmentRule.getFlowLadderList();// 将分段阶梯转换成算法阶梯List<FlowSegmentGoodsClearingAlgorithm.QuantityLadder> ladderList = new ArrayList<>();for (int i = 0; i < flowLadderList.size(); i++) {FlowLadder flowLadder = flowLadderList.get(i);if (i < flowLadderList.size() - 1) {ladderList.add(new FlowSegmentGoodsClearingAlgorithm.QuantityLadder(flowLadder.getBeginLadder(), flowLadderList.get(i + 1).getBeginLadder(), flowLadder.getUnitPrice(), flowLadder.getCalculationType(), flowLadder.getUnit()));} else {ladderList.add(new FlowSegmentGoodsClearingAlgorithm.QuantityLadder(flowLadder.getBeginLadder(), new BigDecimal(Long.MAX_VALUE), flowLadder.getUnitPrice(), flowLadder.getCalculationType(), flowLadder.getUnit()));}}List<QuantityLadderAmountResult> calc = calc(quantityMap, ladderList);calc.forEach(System.out::println);}/*** 账期内数量（流量）分段计算** @param quantityMap key 账期 value 账期使用流量* @param quantityLadderList 分段配置* @return*/public static List<QuantityLadderAmountResult> calc(Map<String, BigDecimal> quantityMap, List<QuantityLadder> quantityLadderList) {Assert.notEmpty(quantityMap, "quantityMap cannot empty");Assert.notEmpty(quantityLadderList, "quantityLadderList cannot empty");List<String> billDateSortList = quantityMap.keySet().stream().sorted(String::compareTo).collect(Collectors.toList());BigDecimal totalFlowMB = BigDecimal.ZERO;List<QuantityLadderAmountResult> resultList = new ArrayList<>();String unit = quantityLadderList.get(0).getUnit();int index = 0;for (String billDate : billDateSortList) {if (null == quantityMap.get(billDate) || BigDecimal.ZERO.equals(quantityMap.get(billDate))) {log.debug("calc 账期 {} 内流量为O,直接返回0元账单", billDate);quantityLadderList.forEach(i -> resultList.add(assembleZeroBill(billDate, i)));continue;}totalFlowMB = totalFlowMB.add(quantityMap.get(billDate));Map<Integer, QuantityLadderAmountResult> resultMap = new HashMap<>();BigDecimal converterUsage;if (FlowUnitEnum.GB.name().equals(unit)) {converterUsage = FlowUnitConverter.toGB(FlowUnitEnum.KB.name(), totalFlowMB);} else if (FlowUnitEnum.MB.name().equals(unit)) {converterUsage = FlowUnitConverter.toMB(FlowUnitEnum.KB.name(), totalFlowMB);} else {converterUsage = totalFlowMB;}// 补已达标废弃的阶梯if (index > 0) {for (int i = 0; i < index; i++) {if (!resultMap.containsKey(i)) {resultMap.put(i, assembleZeroBill(billDate, quantityLadderList.get(i)));}}}for (int i = index; i < quantityLadderList.size(); i++) {QuantityLadder e = quantityLadderList.get(i);BigDecimal matchFlowMB = e.match(converterUsage, quantityMap.get(billDate));if (null == matchFlowMB) {index = i;break;}if (i == quantityLadderList.size() - 1) {index = i;}log.info("calc 账期 {} 总流量 {} 当期流量 {} 中有 {} 命中 {} - ({} , {}]", billDate, converterUsage, quantityMap.get(billDate), matchFlowMB, i, e.getBeginQuantity(), e.getEndQuantity());QuantityLadderAmountResult result = new QuantityLadderAmountResult();result.setBillDate(billDate);result.setQuantity(quantityMap.get(billDate));result.setMatchQuantity(matchFlowMB);result.setAmount(e.calcAmount(matchFlowMB));result.setPriceType(e.getPriceType());result.setPrice(e.getPrice());result.setTotalQuantity(converterUsage);result.setLadderDesc(e.getLadderDesc());result.setLadderIndex(i);result.setUnit(e.getUnit());resultMap.put(i, result);if (converterUsage.compareTo(e.getEndQuantity()) < 0) {index = i;break;}}// 补其他阶梯for (int i = index; i < quantityLadderList.size(); i++) {if (!resultMap.containsKey(i)) {resultMap.put(i, assembleZeroBill(billDate, quantityLadderList.get(i)));}}resultList.addAll(resultMap.values());}return resultList;}private static QuantityLadderAmountResult assembleZeroBill(String billDate, QuantityLadder ladder) {QuantityLadderAmountResult result = new QuantityLadderAmountResult();result.setBillDate(billDate);result.setQuantity(BigDecimal.ZERO);result.setMatchQuantity(BigDecimal.ZERO);result.setAmount(BigDecimal.ZERO);result.setPrice(ladder.getPrice());result.setPriceType(ladder.priceType);result.setUnit(ladder.getUnit());result.setLadderDesc(ladder.getLadderDesc());return result;}@Datapublic static class QuantityLadder {private static final Integer TOTAL_PRICE_FLAG = 1;private boolean isTotalPriceLock = false;/*** 分段开始数量*/private BigDecimal beginQuantity;/*** 分段结束数量*/private BigDecimal endQuantity;/*** 分段价格*/private BigDecimal price;/*** 单位*/private String unit;/*** 价格类型： 0-单价（默认），1-总价*/private Integer priceType;public QuantityLadder() {}public QuantityLadder(BigDecimal beginQuantity, BigDecimal endQuantity, BigDecimal price, Integer priceType, String unit) {this.beginQuantity = beginQuantity;this.endQuantity = endQuantity;this.price = price;this.priceType = priceType;this.unit = unit;}/*** 分段阶梯匹配** @param totalQuantity 账期在整改计算周期内总数量* @param quantity 账期的数量* @return 账期内匹配该阶梯的数量 null 则标识未匹配该阶梯*/public BigDecimal match(BigDecimal totalQuantity, BigDecimal quantity) {boolean isMatch = beginQuantity.compareTo(totalQuantity) < 0;if (!isMatch) {return null;}if (endQuantity.compareTo(totalQuantity) < 0) {return min(endQuantity.subtract(totalQuantity.subtract(quantity)), endQuantity.subtract(beginQuantity));} else {return min(totalQuantity.subtract(beginQuantity), quantity);}}/*** 阶梯内金额计算* 1 当阶梯配置是总价，如果该阶梯没有被计算过，直接返回总价格； 如果被计算过直接返回0* 2 当阶梯计算是单价，** @param matchQuantity* @return*/public BigDecimal calcAmount(BigDecimal matchQuantity) {if (TOTAL_PRICE_FLAG.equals(priceType)) {BigDecimal amount = isTotalPriceLock ? BigDecimal.ZERO : price;isTotalPriceLock = true;return amount;} else {return price.multiply(matchQuantity).setScale(2, RoundingMode.HALF_UP);}}/*** 阶梯描述** @return*/public String getLadderDesc() {if (String.valueOf(Long.MAX_VALUE).equals(endQuantity.toString())) {return MessageFormat.format("({0},{1})", beginQuantity, "+∞");}return MessageFormat.format("({0},{1}]", beginQuantity.toString(), endQuantity.toString());}}private static BigDecimal min(BigDecimal a, BigDecimal b) {return (a.compareTo(b) <= 0) ? a : b;}@Datapublic static class QuantityLadderAmountResult {/*** 账期 实际是业务账期*/private String billDate;/*** 账期内数量*/private BigDecimal quantity;/*** 账期内计算数量*/private BigDecimal matchQuantity;/*** 价格类型： 0-单价（默认），1-总价*/private Integer priceType;/*** 分段价格*/private BigDecimal price;/*** 计算金额*/private BigDecimal amount;/*** 账期在周期内总数量*/private BigDecimal totalQuantity;/*** 匹配分段描述*/private String ladderDesc;/*** 命中阶梯*/private Integer ladderIndex;/*** 流量单位 KB MB GB*/private String unit;/*** 扩展信息*/private String extendInfo;}}
