JodaTime

1.maven引入

<dependency>
  <groupId>joda-time</groupId>
  <artifactId>joda-time</artifactId>
  <version>2.9.9</version>
</dependency>

2.小例子

public class JodaTimeDemo {
    public static void main(String[] args) {
        DateTime dateTime1 = new DateTime(1523428434000L);
        System.out.println(dateTime1.toString("yyyy-MM-dd hh:mm:ss"));
        System.out.println(dateTime1.plusDays(1).toString("yyyy-MM-dd hh:mm:ss"));

        DateTime dateTime2 = new DateTime(
                2000, //year
                1,    // month
                1,    // day
                13,    // hour (midnight is zero)
                0,    // minute
                0,    // second
                0     // milliseconds
        );
        System.out.println(dateTime2.toString("yyyy-MM-dd hh:mm:ss"));

        LocalDate localDate = new LocalDate(2009, 9, 6);
        System.out.println(localDate.toString("yyyy-MM-dd"));

        LocalTime localTime = new LocalTime(13, 30, 26, 0);
        System.out.println(localTime.toString("hh:mm:ss"));

        DateTime dateTime3 = new DateTime(
                2000, //year
                1,    // month
                1,    // day
                1,    // hour (midnight is zero)
                0,    // minute
                0,    // second
                0     // milliseconds
        );
        DateTime dateTime4 = new DateTime(
                2000, //year
                1,    // month
                1,    // day
                13,    // hour (midnight is zero)
                0,    // minute
                0,    // second
                0     // milliseconds
        );
        System.out.println((dateTime4.getMillis() - dateTime3.getMillis()) / 1000 / 3600);
    }
}

3.总结

JodaTime确实比Calendar好用，开发过程中如果使用时间比较多，能够节省很多开发时间。而且JodaTime时间都是不可变的，类似于字符串，也不存在线程安全问题。

官网地址：http://www.joda.org/joda-time/