java 日历工具类（计算周的开始日期和结束日期，以及包好的日期）

柔情只为你懂 2023-10-17 18:12 37阅读 0赞

package com.zxy.product.training.web.util;  
  
  
import java.text.ParseException;  
import java.text.SimpleDateFormat;  
import java.util.ArrayList;  
import java.util.Calendar;  
import java.util.List;  
  
  
public class WeekUtil \{  
/\*\*  
\* 获取指定年份日历  
\* @param year  
\* @return  
\*/  
private static Calendar getCalendarFormYear(int year)\{  
Calendar cal = Calendar.getInstance();  
cal.set(Calendar.DAY\_OF\_WEEK, Calendar.MONDAY);  
cal.set(Calendar.YEAR, year);  
return cal;  
\}  
/\*\*  
\* 获取指定年指定周的开始日期  
\* @param year  
\* @param weekNo  
\* @return  
\*/  
public static String getStartDayOfWeekNo(int year,int weekNo)\{  
Calendar cal = getCalendarFormYear(year);  
cal.set(Calendar.WEEK\_OF\_YEAR, weekNo);  
int month = cal.get(Calendar.MONTH) + 1;  
int day = cal.get(Calendar.DAY\_OF\_MONTH);  
String monthStr = null;  
String dayStr = null;  
StringBuilder monthBuilder = new StringBuilder();  
StringBuilder dayBuilder = new StringBuilder();  
if(month < 10)\{  
monthStr = monthBuilder.append("0").append(month).toString();  
\} else \{  
monthStr = monthBuilder.append(month).toString();  
\}  
if(day < 10) \{  
dayStr = dayBuilder.append("0").append(day).toString();  
\} else \{  
dayStr = dayBuilder.append(day).toString();  
\}  
return cal.get(Calendar.YEAR) + "-" + monthStr + "-" + dayStr;  
  
\}  
  
/\*\*  
\* 获取指定年指定周的结束日期  
\* @param year  
\* @param weekNo  
\* @return  
\*/  
public static String getEndDayOfWeekNo(int year,int weekNo)\{  
Calendar cal = getCalendarFormYear(year);  
cal.set(Calendar.WEEK\_OF\_YEAR, weekNo);  
cal.add(Calendar.DAY\_OF\_WEEK, 6);  
int month = cal.get(Calendar.MONTH) + 1;  
int day = cal.get(Calendar.DAY\_OF\_MONTH);  
String monthStr = null;  
String dayStr = null;  
StringBuilder monthBuilder = new StringBuilder();  
StringBuilder dayBuilder = new StringBuilder();  
if(month < 10)\{  
monthStr = monthBuilder.append("0").append(month).toString();  
\} else \{  
monthStr = monthBuilder.append(month).toString();  
\}  
if(day < 10) \{  
dayStr = dayBuilder.append("0").append(day).toString();  
\} else \{  
dayStr = dayBuilder.append(day).toString();  
\}  
return cal.get(Calendar.YEAR) + "-" + monthStr + "-" + dayStr;  
\}  
  
  
//获取 某日是某年的第几周  
public static int getWeekByDay(String day) throws ParseException \{  
SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");  
Calendar calendar = Calendar.getInstance();  
calendar.setFirstDayOfWeek(Calendar.SUNDAY);  
calendar.setTime(format.parse(day));  
return calendar.get(Calendar.WEEK\_OF\_YEAR);  
\}  
  
//获取 指定开始日期和结束日期，包含日期列表。  
public static List<String> getDays(String beginDate, String endDate) throws ParseException \{  
 List<String> result = new ArrayList<String>();  
 SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");  
Calendar calendar = Calendar.getInstance();  
calendar.setTime(format.parse(beginDate));  
  
for (long time= calendar.getTimeInMillis(); time <= format.parse(endDate).getTime(); time = getNextDay(calendar)) \{  
 result.add(format.format(time));  
\}  
 return result;  
\}  
  
public static long getNextDay(Calendar calendar) \{  
 calendar.set(Calendar.DAY\_OF\_MONTH, calendar.get(Calendar.DAY\_OF\_MONTH) + 1);  
return calendar.getTimeInMillis();  
\}  
  
/\*\*  
\* @param args  
\* @throws ParseException  
\*/  
public static void main(String\[\] args) throws ParseException\{  
 String day = "2016-12-31";  
int week = WeekUtil.getWeekByDay(day);  
  
System.out.println("第"+week+"周");  
System.out.println("第"+week+"周开始日期："+WeekUtil.getStartDayOfWeekNo(2016, week));  
System.out.println("第"+week+"周结束日期："+WeekUtil.getEndDayOfWeekNo(2016, week));  
  
String beginDate = WeekUtil.getStartDayOfWeekNo(2016, week);  
String endDate = WeekUtil.getEndDayOfWeekNo(2016, week);  
  
WeekUtil.getDays(beginDate,endDate).stream().forEach(item -> System.out.println("日期:"+item));  
  
  
\}  
  
  
\}