Java日期时间调整的几种方式汇总

Calendar c = Calendar.getInstance();//默认是当前日期

//创建一个代表2009年6月12日的Calendar对象
Calendar c1 = Calendar.getInstance();
c1.set(2009, 6 - 1, 12)

Calendar c1 = Calendar.getInstance();

public final void set(int year,int month,int date)

c1.set(2009, 6 - 1, 12);//把Calendar对象c1的年月日分别设这为：2009、5、12

public void set(int field,int value)

c1.set(Calendar.DATE,10);

c1.set(Calendar.YEAR,2008);

Calendar c1 = Calendar.getInstance();

c1.add(Calendar.DATE, 10);

c1.add(Calendar.DATE, -10);

Calendar c1 = Calendar.getInstance();
// 获得年份
int year = c1.get(Calendar.YEAR);
// 获得月份
int month = c1.get(Calendar.MONTH) + 1;
// 获得日期
int date = c1.get(Calendar.DATE);
// 获得小时
int hour = c1.get(Calendar.HOUR_OF_DAY);
// 获得分钟
int minute = c1.get(Calendar.MINUTE);
// 获得秒
int second = c1.get(Calendar.SECOND);
// 获得星期几（注意（这个与Date类是不同的）：1代表星期日、2代表星期1、3代表星期二，以此类推）
int day = c1.get(Calendar.DAY_OF_WEEK);

import java.util.*;
public class GregorianCalendarDemo {
   public static void main(String args[]) {
      String months[] = {
      "Jan", "Feb", "Mar", "Apr",
      "May", "Jun", "Jul", "Aug",
      "Sep", "Oct", "Nov", "Dec"};
      int year;
      // 初始化 Gregorian 日历
      // 使用当前时间和日期
      // 默认为本地时间和时区
      GregorianCalendar gcalendar = new GregorianCalendar();
      // 显示当前时间和日期的信息
      System.out.print("Date: ");
      System.out.print(months[gcalendar.get(Calendar.MONTH)]);
      System.out.print(" " + gcalendar.get(Calendar.DATE) + " ");
      System.out.println(year = gcalendar.get(Calendar.YEAR));
      System.out.print("Time: ");
      System.out.print(gcalendar.get(Calendar.HOUR) + ":");
      System.out.print(gcalendar.get(Calendar.MINUTE) + ":");
      System.out.println(gcalendar.get(Calendar.SECOND));
      // 测试当前年份是否为闰年
      if(gcalendar.isLeapYear(year)) {
         System.out.println("当前年份是闰年");
      }
      else {
         System.out.println("当前年份不是闰年");
      }
   }
}

static Period of(int years,int months, int days)
static Period ofDays(int days)
static Period ofMonths(int months)
static Period ofWeeks(int weeks)
static Period ofYears(int years)

import java.time.Period;
public class Main {
  public static void main(String[] args) {
    Period p1 = Period.of(2, 3, 5); // 2 years, 3 months, and 5 days
    Period p2 = Period.ofDays(2);  // 2 days
    Period p3 = Period.ofMonths(-3); // -3 months
    Period p4 = Period.ofWeeks(3); // 3 weeks 
    System.out.println(p1);
    System.out.println(p2);
    System.out.println(p3);
    System.out.println(p4);
  }
}

import java.time.Period;
public class Main {
  public static void main(String[] args) {
    Period p1  = Period.ofDays(15);
    System.out.println(p1);
    Period p2  = p1.plusDays(12);
    System.out.println(p2);
    Period p3  = p1.minusDays(12);
    System.out.println(p3);
    Period p4  = p1.negated();
    System.out.println(p4);
    Period p5  = p1.multipliedBy(3);
    System.out.println(p5);
  }
}

import java.time.Period;
public class Main {
  public static void main(String[] args) {
    Period p1  = Period.of(2, 3, 5); 
    Period p2  = Period.of(1, 15,   28);
    System.out.println(p1); 
    System.out.println(p2);
    System.out.println(p1.minus(p2));
    System.out.println(p1.plus(p2));
    System.out.println(p1.plus(p2).normalized()); 
  }
}

import java.time.LocalDate;
import java.time.LocalTime;
import java.time.Month;
import java.time.temporal.ChronoUnit;
public class Main {
  public static void main(String[] args) {
    LocalDate ld1  = LocalDate.of(2014, Month.JANUARY,  7); 
    LocalDate ld2  = LocalDate.of(2014, Month.MAY,  21); 
    long  days  = ChronoUnit.DAYS.between(ld1, ld2);
    System.out.println(days);
    LocalTime  lt1 = LocalTime.of(6, 0); 
    LocalTime  lt2 = LocalTime.of(9, 30); 
    long  hours   = ChronoUnit.HOURS.between(lt1, lt2);
    System.out.println(hours);
    long  minutes = ChronoUnit.MINUTES.between(lt1,   lt2);
    System.out.println(minutes);
  }
}

import java.time.LocalDate;
import java.time.LocalTime;
import java.time.Month;
import java.time.temporal.ChronoUnit;
public class Main {
  public static void main(String[] args) {
    LocalDate ld1 = LocalDate.of(2014, Month.JANUARY, 7);
    LocalDate ld2 = LocalDate.of(2014, Month.MAY, 18);
    LocalTime lt1 = LocalTime.of(7, 0);
    LocalTime lt2 = LocalTime.of(9, 30);
    long days = ld1.until(ld2, ChronoUnit.DAYS);
    System.out.println(days);
    long hours = lt1.until(lt2, ChronoUnit.HOURS);
    System.out.println(hours);
    long minutes = lt1.until(lt2, ChronoUnit.MINUTES);
    System.out.println(minutes);
  }
}

import java.time.DayOfWeek;
import java.time.LocalDate;
import java.time.Month;
import java.time.temporal.TemporalAdjusters;
public class Main {
  public static void main(String[] args) {
    LocalDate ld1  = LocalDate.of(2014, Month.JANUARY,  1);
    LocalDate ld2  = ld1.with(TemporalAdjusters.next(DayOfWeek.MONDAY)); 
    System.out.println(ld1);
    System.out.println(ld2);
  }
}

import java.time.DayOfWeek;
import java.time.LocalDate;
import java.time.Month;
import java.time.temporal.TemporalAdjusters;
public class Main {
  public static void main(String[] args) {
    LocalDate ld1  = LocalDate.of(2014, Month.MAY,  21);
    System.out.println(ld1);
    LocalDate ld2  = ld1.with(TemporalAdjusters.dayOfWeekInMonth(5, DayOfWeek.SUNDAY));
    System.out.println(ld2);
  }
}

import java.time.LocalDate;
import java.time.temporal.TemporalAdjuster;
import java.time.temporal.TemporalAdjusters;
public class Main {
  public static void main(String[] args) {
    // Create an adjuster that retruns a date after 3 months and 2 days
    TemporalAdjuster adjuster = TemporalAdjusters
        .ofDateAdjuster((LocalDate date) -> date.plusMonths(3).plusDays(2));
    LocalDate today = LocalDate.now();
    LocalDate dayAfter3Mon2Day = today.with(adjuster);
    System.out.println("Today: " + today);
    System.out.println("After 3  months  and  2  days: " + dayAfter3Mon2Day);
  }
}