非常好用的日期工具类
package com.liqiliang.health.resources.utils;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.*;
/**
* 日期操作工具类
*/
public class DateUtils {
/**
* 日期转换- String -> Date
*
* @param dateString 字符串时间
* @return Date类型信息
* @throws Exception 抛出异常
*/
public static Date parseString2Date(String dateString) {
if (dateString == null) {
return null;
}
try {
return parseString2Date(dateString, "yyyy-MM-dd");
} catch (Exception e) {
e.printStackTrace();
throw new RuntimeException("传入字符串必须：yyyy-MM-dd");
}
}
/**
* 日期转换- String -> Date
*
* @param dateString 字符串时间
* @param pattern 格式模板
* @return Date类型信息
* @throws Exception 抛出异常
*/
public static Date parseString2Date(String dateString, String pattern) {
if (dateString == null) {
return null;
}
try {
SimpleDateFormat sdf = new SimpleDateFormat(pattern);
Date date = sdf.parse(dateString);
return date;
} catch (ParseException e) {
e.printStackTrace();
throw new RuntimeException("传入字符串必须：yyyy/MM/dd");
}
}
/**
* 日期转换 Date -> String
*
* @param date Date类型信息
* @return 字符串时间
* @throws Exception 抛出异常
*/
public static String parseDate2String(Date date) throws Exception {
if (date == null) {
return null;
}
return parseDate2String(date, "yyyy-MM-dd");
}
/**
* 日期转换 Date -> String
*
* @param date Date类型信息
* @param pattern 格式模板
* @return 字符串时间
* @throws Exception 抛出异常
*/
public static String parseDate2String(Date date, String pattern) {
if (date == null) {
return null;
}
try {
SimpleDateFormat sdf = new SimpleDateFormat(pattern);
String strDate = sdf.format(date);
return strDate;
} catch (Exception e) {
e.printStackTrace();
throw new RuntimeException(e);
}
}
/**
* 获取当前日期的本周一是几号
*
* @return 本周一的日期
*/
public static Date getThisWeekMonday() {
Calendar cal = Calendar.getInstance();
cal.setTime(new Date());
// 获得当前日期是一个星期的第几天
int dayWeek = cal.get(Calendar.DAY_OF_WEEK);
if (1 == dayWeek) {
cal.add(Calendar.DAY_OF_MONTH, -1);
}
// 设置一个星期的第一天，按中国的习惯一个星期的第一天是星期一
cal.setFirstDayOfWeek(Calendar.MONDAY);
// 获得当前日期是一个星期的第几天
int day = cal.get(Calendar.DAY_OF_WEEK);
// 根据日历的规则，给当前日期减去星期几与一个星期第一天的差值
cal.add(Calendar.DATE, cal.getFirstDayOfWeek() - day);
return cal.getTime();
}
/**
* 获取当前日期周的最后一天
*
* @return 当前日期周的最后一天
*/
public static Date getSundayOfThisWeek() {
Calendar c = Calendar.getInstance();
int dayOfWeek = c.get(Calendar.DAY_OF_WEEK) - 1;
if (dayOfWeek == 0) {
dayOfWeek = 7;
}
c.add(Calendar.DATE, -dayOfWeek + 7);
return c.getTime();
}
/**
* 根据日期区间获取月份列表
*
* @param minDate 开始时间
* @param maxDate 结束时间
* @return 月份列表
* @throws Exception
*/
public static List<String> getMonthBetween(String minDate, String maxDate, String format) throws Exception {
ArrayList<String> result = new ArrayList<>();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM");
Calendar min = Calendar.getInstance();
Calendar max = Calendar.getInstance();
min.setTime(sdf.parse(minDate));
min.set(min.get(Calendar.YEAR), min.get(Calendar.MONTH), 1);
max.setTime(sdf.parse(maxDate));
max.set(max.get(Calendar.YEAR), max.get(Calendar.MONTH), 2);
SimpleDateFormat sdf2 = new SimpleDateFormat(format);
Calendar curr = min;
while (curr.before(max)) {
result.add(sdf2.format(curr.getTime()));
curr.add(Calendar.MONTH, 1);
}
return result;
}
/**
* 根据日期获取年度中的周索引
*
* @param date 日期
* @return 周索引
* @throws Exception
*/
public static Integer getWeekOfYear(String date) throws Exception {
Date useDate = parseString2Date(date);
Calendar cal = Calendar.getInstance();
cal.setTime(useDate);
return cal.get(Calendar.WEEK_OF_YEAR);
}
/**
* 根据年份获取年中周列表
*
* @param year 年分
* @return 周列表
* @throws Exception
*/
public static Map<Integer, String> getWeeksOfYear(String year) throws Exception {
Date useDate = parseString2Date(year, "yyyy");
Calendar cal = Calendar.getInstance();
cal.setTime(useDate);
//获取年中周数量
int weeksCount = cal.getWeeksInWeekYear();
Map<Integer, String> mapWeeks = new HashMap<>(55);
for (int i = 0; i < weeksCount; i++) {
cal.get(Calendar.DAY_OF_YEAR);
mapWeeks.put(i + 1, parseDate2String(getFirstDayOfWeek(cal.get(Calendar.YEAR), i)));
}
return mapWeeks;
}
/**
* 获取某年的第几周的开始日期
*
* @param year 年分
* @param week 周索引
* @return 开始日期
* @throws Exception
*/
public static Date getFirstDayOfWeek(int year, int week) throws Exception {
Calendar c = new GregorianCalendar();
c.set(Calendar.YEAR, year);
c.set(Calendar.MONTH, Calendar.JANUARY);
c.set(Calendar.DATE, 1);
Calendar cal = (GregorianCalendar) c.clone();
cal.add(Calendar.DATE, week * 7);
return getFirstDayOfWeek(cal.getTime());
}
/**
* 获取某年的第几周的结束日期
*
* @param year 年份
* @param week 周索引
* @return 结束日期
* @throws Exception
*/
public static Date getLastDayOfWeek(int year, int week) throws Exception {
Calendar c = new GregorianCalendar();
c.set(Calendar.YEAR, year);
c.set(Calendar.MONTH, Calendar.JANUARY);
c.set(Calendar.DATE, 1);
Calendar cal = (GregorianCalendar) c.clone();
cal.add(Calendar.DATE, week * 7);
return getLastDayOfWeek(cal.getTime());
}
/**
* 获取当前时间所在周的开始日期
*
* @param date 当前时间
* @return 开始时间
*/
public static Date getFirstDayOfWeek(Date date) {
Calendar c = new GregorianCalendar();
c.setFirstDayOfWeek(Calendar.SUNDAY);
c.setTime(date);
c.set(Calendar.DAY_OF_WEEK, c.getFirstDayOfWeek());
return c.getTime();
}
/**
* 获取当前时间所在周的结束日期
*
* @param date 当前时间
* @return 结束日期
*/
public static Date getLastDayOfWeek(Date date) {
Calendar c = new GregorianCalendar();
c.setFirstDayOfWeek(Calendar.SUNDAY);
c.setTime(date);
c.set(Calendar.DAY_OF_WEEK, c.getFirstDayOfWeek() + 6);
return c.getTime();
}
//获得上周一的日期
public static Date geLastWeekMonday(Date date) {
Calendar cal = Calendar.getInstance();
cal.setTime(getThisWeekMonday(date));
cal.add(Calendar.DATE, -7);
return cal.getTime();
}
//获得本周一的日期
public static Date getThisWeekMonday(Date date) {
Calendar cal = Calendar.getInstance();
cal.setTime(date);
// 获得当前日期是一个星期的第几天
int dayWeek = cal.get(Calendar.DAY_OF_WEEK);
if (1 == dayWeek) {
cal.add(Calendar.DAY_OF_MONTH, -1);
}
// 设置一个星期的第一天，按中国的习惯一个星期的第一天是星期一
cal.setFirstDayOfWeek(Calendar.MONDAY);
// 获得当前日期是一个星期的第几天
int day = cal.get(Calendar.DAY_OF_WEEK);
// 根据日历的规则，给当前日期减去星期几与一个星期第一天的差值
cal.add(Calendar.DATE, cal.getFirstDayOfWeek() - day);
return cal.getTime();
}
//获得下周一的日期
public static Date getNextWeekMonday(Date date) {
Calendar cal = Calendar.getInstance();
cal.setTime(getThisWeekMonday(date));
cal.add(Calendar.DATE, 7);
return cal.getTime();
}
//获得今天日期
public static Date getToday() {
return new Date();
}
//获得本月一日的日期
public static Date getFirstDay4CurrentMonth() {
Calendar calendar = Calendar.getInstance();
calendar.set(Calendar.DAY_OF_MONTH, 1);
return calendar.getTime();
}
// 获取指定年和月 的最后一天日期
public static Date getLastDayOfYearAndMonth(int year, int month) {
//获取Calendar类的实例
Calendar c = Calendar.getInstance();
//设置年份
c.set(Calendar.YEAR, year);
//设置月份，因为月份从0开始，所以用month - 1
c.set(Calendar.MONTH, month - 1);
//获取当前时间下，该月的最大日期的数字
int lastDay = c.getActualMaximum(Calendar.DAY_OF_MONTH);
//将获取的最大日期数设置为Calendar实例的日期数
c.set(Calendar.DAY_OF_MONTH, lastDay);
//获取当前月第一天c.set(Calendar.DAY_OF_MONTH, lastDay);
Date time = c.getTime();
String parseDate2String = parseDate2String(time, "yyyy/MM/dd");
Date date = parseString2Date(parseDate2String, "yyyy/MM/dd");
return date;
}
// 获取传入日期所在月的最后一天
public static Date getLastDayOfMonth( Date date) {
final Calendar cal = Calendar.getInstance();
cal.setTime(date);
final int last = cal.getActualMaximum(Calendar.DAY_OF_MONTH);
cal.set(Calendar.DAY_OF_MONTH, last);
return cal.getTime();
}
// 获取传入日期所在月的第一天
public static Date getFirstDayDateOfMonth(Date date) {
final Calendar cal = Calendar.getInstance();
cal.setTime(date);
final int last = cal.getActualMinimum(Calendar.DAY_OF_MONTH);
cal.set(Calendar.DAY_OF_MONTH, last);
return cal.getTime();
}
// 获取当前过去12个月 年-月
public static List<String> getLast12PerMonth (){
//获取日历对象
Calendar calendar = Calendar.getInstance();
//设置日历往前推12个月
calendar.add(Calendar.MONTH,-12);
List list = new ArrayList();
for(int i=0;i<12;i++){
//获取每个月的时间
Date time = calendar.getTime();
//获取每个月的月份
String month = new SimpleDateFormat("yyyy-MM").format(time);
String beginDate = month;
list.add(beginDate);
calendar.add(Calendar.MONTH,1);
}
return list;
}
// 获取当前过去12个月 年-月-日
public static List<String> getLast12FirstDatePerMonth (){
//获取日历对象
Calendar calendar = Calendar.getInstance();
//设置日历往前推12个月
calendar.add(Calendar.MONTH,-12);
List list = new ArrayList();
for(int i=0;i<12;i++){
//获取每个月的时间
Date time = calendar.getTime();
//获取每个月的月份
String month = new SimpleDateFormat("yyyy-MM").format(time);
String beginDate = month+"-1";
list.add(beginDate);
calendar.add(Calendar.MONTH,1);
}
return list;
}
// 获取当前过去12个月
public static List<String> getLast12EndDatePerMonth (){
//获取日历对象
Calendar calendar = Calendar.getInstance();
//设置日历往前推12个月
calendar.add(Calendar.MONTH,-12);
List list = new ArrayList();
for(int i=0;i<12;i++){
//获取每个月的时间
Date time = calendar.getTime();
//获取每个月的月份
String month = new SimpleDateFormat("yyyy-MM").format(time);
String beginDate = month+"-31";
list.add(beginDate);
calendar.add(Calendar.MONTH,1);
}
return list;
}
public static void main(String[] args) throws Exception {
// try {
// System.out.println("本周一" + parseDate2String(getThisWeekMonday()));
// System.out.println("本月一日" + parseDate2String(getFirstDay4ThisMonth()));
// } catch (Exception e) {
// e.printStackTrace();
// }
// Date date = parseString2Date("2020/1/2","yyyy/MM/dd");
// System.out.println(date);
// System.out.println(getLast12FirstDatePerMonth());
// System.out.println(getLast12EndDatePerMonth());
// Date lastDayOfMonth = getLastDayOfMonth(new Date());
// System.out.println(lastDayOfMonth);
// Date firstDayDateOfMonth = getFirstDayDateOfMonth(new Date());
// System.out.println(firstDayDateOfMonth);
// Date f = new Date();
// System.out.println(f.getDate());
}
}
``` java
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