java8新特性之 时间日期Api的用法

/**
 * 1:LocalDate
 * 2:LocalTime
 * 3:LocalDateTime
 *
 */
@Test
public void test1() {
    //获取当前时间
    LocalDateTime time = LocalDateTime.now();
    //2018-07-10T18:28:59.885
    System.out.println(time);


    //加两天
    time.plusDays( 2 );
    //加小时
    time.plusHours( 1 );
    //加分钟
    time.plusMinutes( 12 );

    //减2天
    time.minusDays( 2 );
    //减2小时
    time.minusHours( 2 );

    //得到年
    time.getYear();
    //得到月
    time.getMonth().getValue();


    //
    LocalDateTime time1 = LocalDateTime.of( 2015,7,10,6,30,20 );
    //2015-07-10T06:30:20
    System.out.println(time1);
}


/**
 *时间戳 : 以Unix元年 1970年1月1日 00:00:00 到某个时间之间的毫秒值
 */
@Test
public void test2() {
    //默认获取的是UTC时区时差是8个小时
    Instant instant1 = Instant.now();
    OffsetDateTime of = instant1.atOffset( ZoneOffset.ofHours( 8 ) );
    System.out.println(of);


    //得到时间戳  单位是毫秒
    long l = instant1.toEpochMilli();
    System.out.println(instant1.toEpochMilli());

    //在元年的基础上加60秒
    Instant instant2 = Instant.ofEpochSecond( 60 );
    System.out.println(instant2);
}


/**
 *  Duration: 计算两个时间之间的间隔
    Period : 计算两个日期之间的间隔
 */
@Test
public void test3() {
    Instant instant1 = Instant.now();

    try {
        Thread.sleep( 1000 );
    } catch (InterruptedException e) {
        e.printStackTrace( );
    }

    Instant instant2 = Instant.now();

    Duration duration = Duration.between( instant1,instant2 );
    //秒
    System.out.println(duration.getSeconds());

    //纳秒
    System.out.println(duration.getNano());
    
    //毫秒
    System.out.println(duration.toMillis());


    LocalDate localDate1 = LocalDate.now();

    try {
        Thread.sleep( 1000 );
    } catch (InterruptedException e) {
        e.printStackTrace( );
    }
    //获取时间之前的间隔
    LocalTime  localDate2 = LocalTime.now();
    Duration duration1 = Duration.between( localDate1,localDate2 );
    System.out.println(duration1.toMillis());
}


/**
 * Period : 计算两个日期之间的间隔
 */
@Test
public void test4() {
    LocalDate localDate1 = LocalDate.of( 2015,10,20 );
    LocalDate localDate2 = LocalDate.now();
    Period period = Period.between( localDate1,localDate2 );
    //相差的年月日
    System.out.println(period.getYears());
    System.out.println(period.getMonths());
    System.out.println(period.getDays());
}


/**
 * TemporalAdjuster : 时间矫正器
 *
 */
@Test
public void test5() {
    LocalDateTime dateTime = LocalDateTime.now( );
    LocalDateTime time = dateTime.withDayOfMonth( 10 );
    System.out.println( time );


    //下个周二
    LocalDateTime time1 = dateTime.with( TemporalAdjusters.next( DayOfWeek.FRIDAY ) );
    System.out.println( time1 );

    //自定义: 下一个工作日
    dateTime.with( (x) -> {
        LocalDateTime localDateTime = (LocalDateTime) x;
        DayOfWeek dayOfWeek = localDateTime.getDayOfWeek( );
        if (dayOfWeek.equals( DayOfWeek.FRIDAY )) {
            localDateTime.plusDays( 3 );
            return localDateTime;
        }else if (dayOfWeek.equals( DayOfWeek.MONDAY )) {
            localDateTime.plusDays( 2 );
            return localDateTime;
        }
        return localDateTime;
    });
}


/**
 * DateTimeFormatter : 格式化时间或者日期
 */
@Test
public void test6() {
    //定义格式
    DateTimeFormatter dtf = DateTimeFormatter.ISO_LOCAL_TIME;
    LocalDateTime localDateTime = LocalDateTime.now();
    String s = localDateTime.format( dtf );
    /**
     * 20180716
     */
    System.out.println(s);




    //自定义格式
    DateTimeFormatter dtf2 = DateTimeFormatter.ofPattern( "yyyy年MM月dd日 HH:mm:ss");
    /**
     * 2018年07月16日 18:00:38
     */
   String s1 =  dtf2.format( localDateTime );
   System.out.println(s1);


   //将字符串转化为时间格式
   LocalDateTime localDateTime1 = LocalDateTime.parse( s1,dtf2 );
   System.out.println(localDateTime1);


}


/**
 * 时区的处理
 *
 * ZoneDate
 * ZoneTime
 * ZoneDateTime
 */
@Test
public void test7() {
    Set<String> strings =  ZoneId.getAvailableZoneIds();
    /**
     * 显示所有时区
     * [Asia/Aden, America/Cuiaba, Etc/GMT+9, Etc/GMT+8, Africa/Nairobi]
     */
    System.out.println(strings);


    /**
     * 指定时区,构建时间
     */
    LocalDateTime time = LocalDateTime.now(ZoneId.of( "America/Cuiaba" ));
    //2018-07-16T23:10:28.350
    System.out.println(time);


    /**
     * 2018-07-16T23:17:06.158+08:00[Asia/Shanghai]
     */
    ZonedDateTime zt = time.atZone( ZoneId.of( "Asia/Shanghai" ) );
    System.out.println(zt);

}