英文:
Create new object inside inside Collectors.mapper loop?
问题
我有这段代码：
Map<LocalDate, Map<String, List<RollingField>>> fieldMap = rollingFields.stream()
.collect(Collectors.groupingBy(RollingField::getDate,
Collectors.groupingBy(fi -> fi.getMeta().getName())));
我有一个名为 rollingFieldsToRollingDTO 的方法，该方法将从 List<RollingField> 转换为 ShortRollingFieldDTO。
如何使用 Collectors.mapping 创建它？现在我有一个想法，类似于：
Map<LocalDate, List<ShortRollingFieldDTO>> rollingFieldFrontDTOS = rollingFields.stream()
.collect(Collectors.groupingBy(AbstractField::getDate,
Collectors.mapping(rf -> new ShortRollingFieldDTO(), Collectors.toList())));
英文:
I have this code:
Map<LocalDate, Map<String, List<RollingField>>> fieldMap = rollingFields.stream()
.collect(Collectors.groupingBy(RollingField::getDate,
Collectors.groupingBy(fi -> fi.getMeta().getName())));
And i have method rollingFieldsToRollingDTO which doing from List<RollingField> to ShortRollingFieldDTO
How can i create it with Collectors.mapping? Now i have idea like:
Map<LocalDate, List<ShortRollingFieldDTO>> rollingFieldFrontDTOS = rollingFields.stream()
.collect(Collectors.groupingBy(AbstractField::getDate,
Collectors.mapping(rf -> new ShortRollingFieldDTO(), Collectors.toList())));
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