Java对含有null的集合进行排序

Java对含有null的集合进行排序"/>

Java对含有null的集合进行排序

1.原始comparator

public static List<ReportVehicleVo> sortByBuildingPhaseAndFdeName(List<ReportVehicleVo> list){list.sort(new Comparator<ReportVehicleVo>() {@Overridepublic int compare(ReportVehicleVo o1, ReportVehicleVo o2) {if (StringUtils.isBlank(o1.getVeBuildingPhase())){return -1;}if (StringUtils.isBlank(o2.getVeBuildingPhase())){return 1;}if (o1.getVeBuildingPhase()pareTo(o2.getVeBuildingPhase()) > 0){return 1;}else if (o1.getVeBuildingPhase()pareTo(o2.getVeBuildingPhase()) < 0){return -1;}else {if (StringUtils.isBlank(o1.getFdeName())){return -1;}if (StringUtils.isBlank(o2.getFdeName())){return 1;}if (o1.getFdeName()pareTo(o2.getFdeName()) > 0){return 1;}else {return -1;}}}});return list;}

原始方法判空后再排序

2.优雅方式

List<String> testingPlaceList = new ArrayList<>();
testingPlaceList.sort(Comparator.nullsFirst(Comparator.naturalOrder()));

下边一行代码执行完就排好序了，并且nullsFirst会把null值排到前边，如果你想排到后边就换成nullsLast，另外naturalOrder是正序，如果你想倒序就换成reverseOrder