集合按某个属性排序，含null

1.对象

@Data
public class CustInfo{
    private static final long serialVersionUID = -5035380693671995905L;
    private String uuid;
    //客户名称
    private String custName;
    private String lastUpdateTm;	
    private String distance; //距离
    }

2.集合单字段排序

Comparator<CustInfo> cmp =null;
	//升序
  // cmp = Comparator.nullsLast(Comparator.comparing(CustInfo::getDistance, Comparator.nullsLast(String::compareTo)));
  //降序
  Comparator.nullsLast(Comparator.comparing(CustInfo::getDistance, Comparator.nullsLast(String::compareTo))).reversed();
  list = list.stream().sorted(cmp).collect(Collectors.toList());

3.集合多字段组合排序

Comparator<CustInfo> cmp1 =null;
  cmp1 = Comparator.nullsLast(Comparator.comparing(CustInfo::getDistance, Comparator.nullsLast(String::compareTo)));
  Comparator<CustInfo> cmp2 =null;
   cmp2 = Comparator.nullsLast(Comparator.comparing(CustInfo::getLastUpdateTm,Comparator.nullsLast(String::compareTo)));
   //组合排序，先根据距离排序，再根据时间排序
   Comparator<CustInfo> finalCmp = cmp1.thenComparing(cmp2);
  list = list.stream().sorted(finalCmp).collect(Collectors.toList());