获取指定月份周明细
package com.ruoyi.ad.util;
import java.text.SimpleDateFormat;
import java.time.*;
import java.time.temporal.ChronoUnit;
import java.time.temporal.TemporalAdjusters;
import java.time.temporal.WeekFields;
import java.util.Date;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;
import java.util.stream.Stream;
/**
* @author： 谢辉
* @date： 2021/4/14
* @email: xieh_mail@163.com
* @description： 获取每个月有几周，并且每周的开始日期和结束日期
* 国内都是以周一开始，注：即使第一天是周末，也算一周
* @modifiedBy：
* @version: 1.0
*/
public class AdDateUtils {
/**
* 获取指定月份有几周，每周的开始日期和结束日期
*
* @param yearMonth
* @return
*/
public static Map<Integer, WeekData> weeks(YearMonth yearMonth) {
// 获取指定月份的第一天
LocalDate start = LocalDate.now().with(yearMonth).with(TemporalAdjusters.firstDayOfMonth());
// 获取指定月份的最后一天
LocalDate end = LocalDate.now().with(yearMonth).with(TemporalAdjusters.lastDayOfMonth());
Map<Integer, WeekData> map = Stream.iterate(start, localDate -> localDate.plusDays(1l))
.limit(ChronoUnit.DAYS.between(start, end) + 1)
// DayOfWeek.MONDAY 这里是指定周一（MONDAY）为一周的开始
.collect(Collectors.groupingBy(localDate -> localDate.get(WeekFields.of(DayOfWeek.MONDAY, 1).weekOfMonth()),
Collectors.collectingAndThen(Collectors.toList(), WeekData::new)));
return map;
}
/**
* 获取指定时期的后面月份的第一天开始时间
*
* @param startDate 开始时间
* @param month 第几个月
* @return
*/
public static Date getMonthDate(Date startDate, int month) {
LocalDateTime localDateTime = startDate.toInstant()
.atZone(ZoneId.systemDefault())
.toLocalDateTime().plusMonths(month);
Date date = Date.from(localDateTime.atZone(ZoneId.systemDefault()).toInstant());
return date;
}
public static class WeekData {
// 一周的开始时间
private LocalDate start;
// 一周的结束时间
private LocalDate end;
public WeekData(List<LocalDate> localDates) {
this.start = localDates.get(0);
this.end = localDates.get(localDates.size() - 1);
}
@Override
public String toString() {
return this.start + "~" + this.end;
}
}
public static void main(String[] args) throws Exception {
System.out.println(weeks(YearMonth.of(2021, 4)));
String targetStr = YearMonth.now().toString() + "-01";
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Date date = getMonthDate(sdf.parse(targetStr), 2);
System.out.println("后2个月的时间:" + sdf.format(date));
}
}
获取两个月份间隔月份明细
package com.demo;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.time.YearMonth;
import java.time.format.DateTimeFormatter;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Collections;
import java.util.Date;
import java.util.List;
/**
* 计算两个月份相隔的明细
* @author XH
*
*/
public class TestDate {
public static int getDay(Date date) {
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
return calendar.get(Calendar.DATE);
}
/** * 返回日期的月份，1-12,即yyyy-MM-dd中的MM * * @param date * @return */
public static int getMonth(Date date) {
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
return calendar.get(Calendar.MONTH) + 1;
}
/** * 返回日期的年,即yyyy-MM-dd中的yyyy * * @param date * Date * @return int */
public static int getYear(Date date) {
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
return calendar.get(Calendar.YEAR);
}
public static int getDaysOfMonth(int year, int month) {
Calendar calendar = Calendar.getInstance();
calendar.set(year, month - 1, 1);
return calendar.getActualMaximum(Calendar.DAY_OF_MONTH);
}
public static int calDiffMonth(String startDate,String endDate){
int result=0;
try {
SimpleDateFormat sfd=new SimpleDateFormat("yyyy-MM");
Date start = sfd.parse(startDate);
Date end = sfd.parse(endDate);
int startYear=getYear(start);
int startMonth=getMonth(start);
int startDay=getDay(start);
int endYear=getYear(end);
int endMonth=getMonth(end);
int endDay=getDay(end);
if (startDay>endDay){ //1月17 大于 2月28
if (endDay==getDaysOfMonth(getYear(new Date()),2)){ //也满足一月
result=(endYear-startYear)*12+endMonth-startMonth;
}else{
result=(endYear-startYear)*12+endMonth-startMonth-1;
}
}else{
result=(endYear-startYear)*12+endMonth-startMonth;
}
} catch (ParseException e) {
e.printStackTrace();
}
return result;
}
public static List<String> getBetweenDateByMonth(String startDate,String endDate){
List<String> results = new ArrayList<String>();
// 判断两个月份的间隔数量
int count = calDiffMonth(startDate,endDate);
// 如果两个日期相等
if(count == 0) {
results.add(startDate);
results.add(endDate);
return results;
}
if(count > 0) {
YearMonth now = YearMonth.parse(startDate, DateTimeFormatter.ofPattern("yyyy-MM"));
results.add(startDate);
for (int i = 1; i <= count; i++) {
// 参数-1 是获取下个月的月份
YearMonth nextMonths = now.minusMonths(-i);
results.add(nextMonths.toString());
}
return results;
}
if(count < 0) {
YearMonth now = YearMonth.parse(startDate, DateTimeFormatter.ofPattern("yyyy-MM"));
results.add(startDate);
count = Math.abs(count);
for (int i = 1; i <= count; i++) {
// 参数1 是获取上个月的月份
YearMonth nextMonths = now.minusMonths(i);
results.add(nextMonths.toString());
}
Collections.reverse(results);
return results;
//return results;
}
return results;
}
public static void main(String[] args) {
List<String> betweenDateByMonth = getBetweenDateByMonth("2020-04", "2020-08");
System.out.println(betweenDateByMonth.toString());
}
}
补充：
/**
* 根据指定日期开始获取指定数量的下几个月
* 注：包含入参的月份
* @param startDate 开始日期（yyyy-MM）
* @param num 指定数量
* @return
*/
public static List<String> getNextMonthByNum(String startDate,int num){
YearMonth now = YearMonth.parse(startDate, DateTimeFormatter.ofPattern("yyyy-MM"));
List<String> results = new ArrayList<String>();
results.add(now.toString());
if(num <= 0){
return results;
}
for(int i = 1; i <= num; i++){
YearMonth nextMonths = now.minusMonths(-i);
results.add(nextMonths.toString());
}
return results;
}
