LocalDate

1.获取当前时间

LocalDate today = LocalDate.now();

2.获取当前月份

LocalDate today = LocalDate.now();

int month = today.getMonthValue();

3.获取当前日期

LocalDate today = LocalDate.now();

int day = today.getDayOfMonth();

4.获取指定日期

LocalDate date = LocalDate.parse("2020-01-01");  #以获取2020年01月01日为例

5.获取当前时间前/后X天的日期

LocalDate data  = LocalDate.now().plusDays(±X);

获取前一天的日期

LocalDate data  = LocalDate.now().plusDays(-1);

获取后一天的日期

LocalDate data  = LocalDate.now().plusDays(+1);

6.获取本周周一的日期

LocalDate today = LocalDate.now();

LocalDate firstDay = today.with(DayOfWeek.MONDAY);

7.获取本月第一天的日期

LocalDate today = LocalDate.now();

LocalDate firstDay = today.with(TemporalAdjusters.firstDayOfMonth());

8.获取本月的总天数

LocalDate today = LocalDate.now();

int TotalDays = today.withMonth(today.getMonthValue()).lengthOfMonth();

9.获取当前年份的第一天

LocalDate today = LocalDate.now();

LocalDate firsDay = today.with(TemporalAdjusters.firstDayOfYear());

10.LocalDate和String相互转换

LocalDate转String

DateTimeFormatter df = DateTimeFormatter.ofPattern("yyyy-MM-dd");

LocalDate today = LocalDate.now();

String dateStr = today.format(df);

String转LocalDate

DateTimeFormatter df = DateTimeFormatter.ofPattern("yyyy-MM-dd");

String str = "2020-01-01";

LocalDate date = LocalDate.parse(str, fmt);

11.获取两个时间间隔中的每一天

List<String> list = new ArrayList<>();
long distance = ChronoUnit.DAYS.between(startDate, endDate);  #传入开始时间和结束时间
if (distance < 1) {
    return list;
}
Stream.iterate(startDate, d -> d.plusDays(1)).limit(distance + 1).forEach(f -> list.add(f.toString()));
return list;

12.比较两个日期的大小

判断localDate1是否和localDate2相等，返回布尔值

boolean equal = localDate1.isEqual(localDate2);  

判断localDate1是否在localDate2之前，返回布尔值

boolean before = localDate1.isBefore(localDate2);

判断localDate1是否在localDate2之后，返回布尔值

boolean after = localDate1.isAfter(localDate2);

LocalDateTime

1.获取当前时间

LocalDateTime today = LocalDateTime.now();

2.获取当前时间年、月、日、时、分、秒

LocalDateTime today = LocalDateTime.now();
int year = today.getYear();     #年
int month = today.getMonthValue();   #月
int day = today.getDayOfMonth();        #日
int hour = today.getHour();    #时
int minute = today.getMinute();   #分
int second = today.getSecond();   #秒

3.LocalDateTime和String相互转换

LocalDateTime转String

DateTimeFormatter df = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
LocalDateTime today = LocalDateTime.now();
String format = today.format(df);

String转LocalDateTime

DateTimeFormatter df = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
String str = "2020-01-01 11:11:11";
LocalDateTime data = LocalDateTime.parse(str, df);