stream min 使用方法记录

public static void main(String[] args) {
    ArrayList<SaBillVO> saBillVOS = new ArrayList<SaBillVO>();
    SaBillVO sb = new SaBillVO();
    SaBillVO sb1 = new SaBillVO();
    SaBillVO sb2 = new SaBillVO();
    SaBillVO sb3 = new SaBillVO();

    BillVO b = new BillVO();
    b.setReplyTime(LocalDateTime.now());
    BillVO b1 = new BillVO();
    b1.setReplyTime(LocalDateTime.now().plusDays(1));
    BillVO b2 = new BillVO();
    b2.setReplyTime(LocalDateTime.now().plusDays(2));
    BillVO b3 = new BillVO();

    sb.setBillVO(b);
    sb1.setBillVO(b1);
    sb2.setBillVO(b2);
    sb3.setBillVO(b3);

    saBillVOS.add(sb);
    saBillVOS.add(sb1);
    saBillVOS.add(sb2);
    saBillVOS.add(sb3);
    SaBillVO min =
        saBillVOS.stream()
            .min(Comparator.comparing(
                sa -> sa.getBillVO().getReplyTime() != null ? sa.getBillVO().getReplyTime() : LocalDateTime.MAX))
            .get();
}

比较值为空的话会报空指针