jdk1.8集合操作新特性

港控/mmm° 2021-11-22 07:22 353阅读 0赞

jdk1.8出了很多新特性，对集合操作很多，整理了一下方法，供大家使用

Map<String,Supplier> map = materialSupplierList.stream().collect(Collectors.toMap(MaterialSupplier::getMaterialCode, supplier -> supplier));
    
    
    
    List<Long> aggregationItemIdList= resultList.stream().map(PlanAggregationItemListVO::getId).collect(Collectors.toList());
    
    Set<String> materialCodeSet = planItemList.stream().map(PlanItemVO::getMaterialCode).collect(Collectors.toSet()); 
    
    
    String stationCodes = dataList.stream().map(Station::getStationCode).collect(Collectors.joining(","));
    分享一个拼接字符串的方法
    
    // 过滤挂起
    List<StockTransferOrderStatus> statusList = new ArrayList<>();
    List<StockTransferOrderStatus> suspended = statusList.stream().filter(status -> status == StockTransferOrderStatus.SUSPENDED).collect(Collectors.toList()); 
    
    //分组
    Map<Long, List<ShippingBatchItem>> groupMap = batchItemListFiler.stream().collect(Collectors.groupingBy(ShippingBatchItem::getShippingBatchId));
    
    //数量累加求和
    Long shouldCountSum = asnItems.stream().map(OutBoundShippingNoticeItemPo::getCurrQuantity).reduce(Long::sum).get();
    
    List<ReceiptRecordPo> receiptRecordPos = new ArrayList<>();
    goodsReciptEventList.stream().forEach(item -> receiptRecordPos.add(ReceiptRecordPo.build(userName, item, objectMapper)));
    
    
    //MAP
    Map<Long, ReceiptItemPo> receiptItemPoMap = receiptItemList.stream().collect(Collectors.toMap(ReceiptItemPo::getId, item -> item)); 
    Map<Long,UnifiedInventoryEs> map = esList.stream().collect(Collectors.toMap(UnifiedInventoryEs::getUnifiedInventoryId, Function.identity()));
    
    //集合快速过滤设值
    list.stream().forEach(item-> {
    item.setEnabledName(item.getEnabled() ? "启用":"禁用");
    });
    
    
    //按照集合里的参数 拼接成目标集合
    List<String> improtSnList = list.stream().map(d ->d.getMaterialCode()+"_"+d.getMaterialSn()).collect(Collectors.toList());
    
    //通过条件过滤其中数据，再拼装成集合
    List<RmaReturnDetailSn> changePnList = rmaReturnDetailSnList.stream().filter(iteam ->NoRmaReasonDetailTypeEnum.MIX.getType().equals(iteam.getNoRmaReasonDetailType()) && !iteam.getMaterialCode().equals(iteam.getMixMaterialCode())).collect(Collectors.toList());
    //将集合转成另外一种对象集合
    List<UpdateMaterialCodeBySn> repairOrderSnTempList = changePnList.stream().map(RmaReturnDetailSn::buildUpdateMaterialCodeBySn).collect(Collectors.toList());
    
    //List对象转换成map对象
    private Map<Long, List<CloudEntryProjectBindingDto>> getRmProjectIdAndBindingMap(List<CloudEntryProjectBindingDto> rmProjectBindingDtoList) {
            return rmProjectBindingDtoList ==null?null:rmProjectBindingDtoList.stream().collect(Collectors.toMap(CloudEntryProjectBindingDto::getProjectId, s -> {
                List<CloudEntryProjectBindingDto> l = new ArrayList<>();
                l.add(s);
                return l;
            }, (List<CloudEntryProjectBindingDto> s1, List<CloudEntryProjectBindingDto> s2) -> {
                s1.addAll(s2);
                return s1;
            }));
        }
    
    //集合中按照某个字段值正序排列集合对象
     List<BillingRealCostDto> sorted = realCostDtos.stream().sorted(Comparator.comparingInt(BillingRealCostDto::getMonth)).collect(toList());