同事提醒我：不要踩到 LocalDateTime 的这个坑！

    public static void main(String[] args) {
        JDateTime dt = new JDateTime();
        System.out.println(dt.addDay(1));//原对象
        System.out.println(dt);

        LocalDateTime dc = LocalDateTime.now();
        System.out.println(dc.plusDays(1));//新对象
        System.out.println(dc);

        dc = dc.plusDays(1);
        System.out.println(dc);
    }

运行结果：

2019-12-24 18:43:25.283
2019-12-24 18:43:25.283

2019-12-24T18:43:25.364
2019-12-23T18:43:25.364

2019-12-24T18:43:25.364

dc.plusDays(1)  创建了新对象！！

来源：CSDN

作者：Stephen_java

链接：https://blog.csdn.net/u012477144/article/details/103668946