如何分類（過濾）java中的數據8

Question

我有數據點的類。類定義如下：

public class ExciseReportDataPoint { 
    private String liquorCategoryName; 
    private String liquorName; 
    private String nozzleName; 
    private String bottleExciseNumber; 
    private int fixedPegSize; 
    private double costPerPeg; 
    private int bottleSize; 
    private int consumedVolumeInMl; 
    private int volumeInBottleInMl; 
    private boolean isBottleEmpty; 
    private int totalNoOfPegsPoured; 
    private double totalSaleValue; 
    // Getters and setters for all 

} 

我從我的API獲得List<ExciseReportDataPoint>。我想要顯示錶格報告，其中行必須先用LiquorCategory和Liquor進行分類。我想將List<ExciseReportDataPoint>轉換爲Map<String, Map <String, List<List<String>>>>。我不知道是否有可能或不使用流和收藏家

是否有人對此有何看法？

Answer 1

您可以將您的列表幾次：

Map<String, Map<String, List<ExciseReportDataPoint>>> map = list.stream().collect(Collectors.groupingBy(ExciseReportDataPoint::getLiquorCategoryName, Collectors.groupingBy(ExciseReportDataPoint::getLiquorName)));