stream流思想应用

1、计算集合中某字段数值和

subTotal = subTotal+ complainCountResult.stream().filter(childSource->childSource.getSourceId().equals(childSourceId)).mapToInt(DataDictionaryModel::getCount).sum();

 

2、产生新集合

List<XfDictStatisticModel> streamStatisticModelListNew = dictStatisticModelListNew.stream().
                        filter(streamStatisticModel->streamStatisticModel.getCantonCode().equals(xfDictStatisticModel.getParentCantonCode())).collect(Collectors.toList());

 

3、