java8stream流示例

//对象集合中取车某个元素
List<String> li=lists.stream().map(e -> e.getDate().toString()).collect(Collectors.toList());

//字符串数组数据转96点List<Decimal> 集合
List<String> li=JSON.parseArray(gridRealtimeDatas.get(i).getSysActualLoad(), BigDecimal.class)


//对象集合按某一字段分组
Map<LocalDate, List<AheadNonMarketGensetLoad>> map=
lists.stream().collect(Collectors.groupingBy(AheadNonMarketGensetLoad::getDate));

//对象集合中统一设置某个字段
lists.forEach(model -> model.setCompanyName("测试"));

//对象集合按条件检索筛选 返回对象集合
lists=lists.stream().filter(model -> type.equals(model.getDicCode())).collect(Collectors.toList())

//条件判断 返回boolean
boolean a=lists.stream().anyMatch(model -> model.getBackupLoad() == null)

//对象集合转化为map集合
        LinkedHashMap<String, String> gensetMap = genSets.stream().collect(Collectors.toMap(GenSet::getId, GenSet::getName, (n1, n2) -> n1, LinkedHashMap::new));


//设置实体  需在实体类中添加@SuperBuilder
ApplyForecastAlgoParam param = ApplyForecastAlgoParam.builder()
                .forecastDate(forecastDate)
                .occasionType(occasionType)
                .forecastType(ForecastType.WHOLE_PRICE).build();


    //分组数据归类
        LinkedHashMap<String, List<MustBootStopEo>> dispatchNameGroupDataMap
                = mustBootStopEos
                .stream()
                .collect(Collectors.groupingBy(MustBootStopEo::getUnitName, LinkedHashMap::new, Collectors.toList()));


//分组计数 
  Map<String, Long> dmemEOGroupDataMap = memEOStrLi.stream().collect(Collectors.groupingBy(SaleRetailMemberEO::getArea, Collectors.counting()));



 //集合中元素累加求和     
    BigDecimal sum = values.stream().map(MathOperateUtil::objectToDecimal).filter(Objects::nonNull).reduce(BigDecimal.ZERO, BigDecimal::add);
//集合筛选null值计算个数
        long count = values.stream().map(MathOperateUtil::objectToDecimal).filter(Objects::nonNull).count();

  //同一设置集合中某一个元素 
     List<ContractDataBidding> biddingDataList = contract.getBiddingDataList().stream()
                    .peek(item ->
                            item.setContractId(contract.getId())
                    ).collect(Collectors.toList());
//排序
            List<AlgoNodePriceForecast> priceForecasts = nodePriceForecasts.stream().sorted(Comparator.comparing(AlgoNodePriceForecast::getForecastDate).thenComparing(AlgoNodePriceForecast::getForecastOccasion).reversed()).collect(Collectors.toList());

            		   paramList=paramList.stream().sorted(Comparator.comparing(SpotInterprovincialParam::getDate).reversed()).collect(Collectors.toList());




//对象集合转Map 
 Map<String, RealtimeDataBo> dataBoMap =
                    unitRealtimeDataList.stream().collect(Collectors.toMap(DataRealtimeData::getTime,
                            DataRealtimeData::getData));
reportCompanyUnitList
                .stream()
                .collect(Collectors.toMap(ReportCompanyUnit::getId, ReportCompanyUnit::getName));


 Collections.sort(buyPrices);
                    buyMinPrices.add(buyPrices.get(0));
                    Collections.reverse(buyPrices);
                    buyMaxPrices.add(buyPrices.get(0));


  Map<String, List<LocalDate>> groupedMap = dateStrList.stream().collect(Collectors.groupingBy(m -> m.toString().substring(0,7)));