Java 代码优化：计算平均值并分组

public static Map<String, BigDecimal> getAvgMap(final List computeResultExportDTOS, final BigDecimal totality) { return computeResultExportDTOS.stream() .filter(Objects::nonNull) .collect(Collectors.groupingBy(ComputeResultExportDTO::getScoreItemId, Collectors.mapping(ComputeResultExportDTO::getAssessScore, Collectors.toList()))) .entrySet() .stream() .collect(Collectors.toMap( Map.Entry::getKey, v -> v.getValue().stream() .reduce(BigDecimal.ZERO, BigDecimal::add) .divide(totality, ExcelResultComputeUtil.FOUR_DECIMAL_PLACES, RoundingMode.HALF_UP) )); }