关于Calendar的一些用法总结
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import java.util.Calendar;
import java.security.KeyStore.TrustedCertificateEntry;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.ParsePosition;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
/**
* 常用日历操作辅助类
*
*
*/
public class CalendarUtil {
// 用来全局控制 上一周，本周，下一周的周数变化
private int weeks = 0;
private int MaxDate;// 一月最大天数
private int MaxYear;// 一年最大天数
private static Calendar calendar = Calendar.getInstance();//实例化日历
/**测试
* @param args
*/
public static void main(String[] args) {
CalendarUtil tt = new CalendarUtil();
System.out.println("获取当天日期:" + tt.getNowTime("yyyy-MM-dd HH:mm:ss"));
//-------------------------------------------------------------
System.out.println("获取本周一日期:" + tt.getMondayOFWeek());
System.out.println("获取本周日的日期:" + tt.getSundayWeekday());
System.out.println("获取上周日日期:" + tt.getPreviousWeekSunday());
System.out.println("获取上周一日期:" + tt.getPreviousWeekday());
System.out.println("获取下周一日期:" + tt.getNextMonday());
System.out.println("获取下周日日期:" + tt.getNextSunday());
//-------------------------------------------------------------
System.out.println("获取本月第一天日期:" + tt.getFirstDayOfMonth());
System.out.println("获取本月最后一天日期:" + tt.getDefaultDay());
System.out.println("获取上月第一天日期:" + tt.getPreviousMonthFirst());
System.out.println("获取上月最后一天的日期:" + tt.getPreviousMonthEnd());
System.out.println("获取下月第一天日期:" + tt.getNextMonthFirst());
System.out.println("获取下月最后一天日期:" + tt.getNextMonthEnd());
//-------------------------------------------------------------
System.out.println("---------------->");
System.out.println("获取当前月的第几周：" + tt.getWeekOfMonth());
System.out.println("获取当前年份：" + tt.getYear());
System.out.println("获得本年有多少天:"+tt.getMaxYear());
System.out.println("获取当前月份：" + tt.getMonth());
System.out.println("根据日期获得当天周几:" + tt.getWeek("2018-10-15"));
System.out.println("获取今天在本年的第几天：" + tt.getDayOfYear());
System.out.println("获得今天在本月的第几天(获得当前日)：" + tt.getDayOfMonth());
System.out.println("获得今天在本周的第几天：" + tt.getDayOfWeek());
System.out.println("获取两个日期之间间隔天数2018-5-1~2018-4-1:"
+ CalendarUtil.getTwoDay("2018-5-1", "2018-4-1"));
System.out.println("获得半年后的日期：" + tt.convertDateToString(tt.getTimeYearNext()));
//-------------------------------------------------------------
System.out.println("获取本年的第一天日期:" + tt.getCurrentYearFirst());
System.out.println("获取本年最后一天日期:" + tt.getCurrentYearEnd());
System.out.println("获取去年的第一天日期:" + tt.getPreviousYearFirst());
System.out.println("获取去年的最后一天日期:" + tt.getPreviousYearEnd());
System.out.println("获取明年第一天日期:" + tt.getNextYearFirst());
System.out.println("获取明年最后一天日期:" + tt.getNextYearEnd());
//-------------------------季度需单独运行，否则会受之前日期的影响------------------------------------
//System.out.println("获取本季度第一天:" + tt.getThisSeasonFirstTime());
//System.out.println("获取本季度最后一天:" + tt.getThisSeasonFinallyTime());
//-------------------------------------------------------------
System.out.println("得到几天前的日期："+ tt.getDateBefore("2018-6-15", 20));
}
// 获取当天时间
public String getNowTime(String dateformat) {//传入参数为日期的格式
Date now = new Date();
SimpleDateFormat dateFormat = new SimpleDateFormat(dateformat);// 可以方便地修改日期格式
String toDay = dateFormat.format(now);
return toDay;
}
// 获得本周一的日期
public String getMondayOFWeek() {
CalendarUtil tt = new CalendarUtil();
int mondayPlus =tt.getMondayPlus();//调用getMondayPlus方法获得当前日期与本周一相差的天数
GregorianCalendar currentDate = new GregorianCalendar();
currentDate.add(GregorianCalendar.DATE, mondayPlus); //当天天数与相差的天数进行相加得到周一在本周的天数
Date monday = currentDate.getTime(); //根据天数获得时间
DateFormat df = DateFormat.getDateInstance();
String preMonday = df.format(monday);
return preMonday;
}
// 获得当前日期与本周一相差的天数
private int getMondayPlus() {
Calendar cd = Calendar.getInstance();
// 获得今天是一周的第几天，星期日是第一天，星期一是第二天......
int dayOfWeek = cd.get(Calendar.DAY_OF_WEEK) - 1; // 因为按中国礼拜一作为第一天所以这里减1
if (dayOfWeek == 1) {
return 0; //如果是周一 返回0(无相差天数)
} else {
//返回与周一相差的天数(用以当天和相差天数计算)
//如果今天为周五 首先dayOfWeek == 5, 1-5则返回-4,当前减去4天就为周一的日期
return 1 - dayOfWeek;
}
}
// 获得本周星期日的日期
public String getSundayWeekday() {
int mondayPlus = this.getMondayPlus();
GregorianCalendar currentDate = new GregorianCalendar();
currentDate.add(GregorianCalendar.DATE, mondayPlus + 6); //当天天数与相差的天数进行相加得到周日在本周的天数
Date monday = currentDate.getTime();
DateFormat df = DateFormat.getDateInstance();
String preMonday = df.format(monday);
return preMonday;
}
// 获得上周星期日的日期
public String getPreviousWeekSunday() {
weeks = 0;
weeks--;
int mondayPlus = this.getMondayPlus();
GregorianCalendar currentDate = new GregorianCalendar();
currentDate.add(GregorianCalendar.DATE, mondayPlus + weeks); //本周周一的天数减去1天
Date monday = currentDate.getTime();
DateFormat df = DateFormat.getDateInstance();
String preMonday = df.format(monday);
return preMonday;
}
// 获得上周星期一的日期
public String getPreviousWeekday() {
weeks--;
int mondayPlus = this.getMondayPlus();
GregorianCalendar currentDate = new GregorianCalendar();
currentDate.add(GregorianCalendar.DATE, mondayPlus + 7 * weeks);//本周周一的天数减去7天
Date monday = currentDate.getTime();
DateFormat df = DateFormat.getDateInstance();
String preMonday = df.format(monday);
return preMonday;
}
// 获得下周星期一的日期
public String getNextMonday() {
weeks++;
int mondayPlus = this.getMondayPlus();
GregorianCalendar currentDate = new GregorianCalendar();
currentDate.add(GregorianCalendar.DATE, mondayPlus + 7);//本周周一的天数加7天
Date monday = currentDate.getTime();
DateFormat df = DateFormat.getDateInstance();
String preMonday = df.format(monday);
return preMonday;
}
// 获得下周星期日的日期
public String getNextSunday() {
int mondayPlus = this.getMondayPlus();
GregorianCalendar currentDate = new GregorianCalendar();
currentDate.add(GregorianCalendar.DATE, mondayPlus + 7 + 6);
Date monday = currentDate.getTime();
DateFormat df = DateFormat.getDateInstance();
String preMonday = df.format(monday);
return preMonday;
}
//----------------------------------------------------------
// 获取当月第一天
public String getFirstDayOfMonth() {
String str = "";
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Calendar date = Calendar.getInstance();
date.set(Calendar.DATE, 1);// 设为当前月的1号
str = sdf.format(date.getTime());
return str;
}
// 计算当月最后一天,返回字符串
public String getDefaultDay() {
String str = "";
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Calendar date = Calendar.getInstance();
date.set(Calendar.DATE, 1);// 设为当前月的1号
date.add(Calendar.MONTH, 1);// 加一个月，变为下月的1号
date.add(Calendar.DATE, -1);// 减去一天，变为当月最后一天
str = sdf.format(date.getTime());
return str;
}
// 上月第一天
public String getPreviousMonthFirst() {
String str = "";
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Calendar date = Calendar.getInstance();
date.set(Calendar.DATE, 1);// 设为当前月的1号
date.add(Calendar.MONTH, -1);// 减一个月，变为上月的1号
str = sdf.format(date.getTime());
return str;
}
// 获得上月最后一天的日期
public String getPreviousMonthEnd() {
String str = "";
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Calendar date = Calendar.getInstance();
date.add(Calendar.MONTH, -1);// 减一个月
date.set(Calendar.DATE, 1);// 把日期设置为当月第一天
date.roll(Calendar.DATE, -1);// 日期回滚一天，也就是本月最后一天
// date.set(Calendar.DATE, 1);
// date.add(Calendar.DATE,-1);
str = sdf.format(date.getTime());
return str;
}
// 获得下个月第一天的日期
public String getNextMonthFirst() {
String str = "";
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Calendar date = Calendar.getInstance();
date.add(Calendar.MONTH, 1);// 减一个月
date.set(Calendar.DATE, 1);// 把日期设置为当月第一天
str = sdf.format(date.getTime());
return str;
}
// 获得下个月最后一天的日期
public String getNextMonthEnd() {
String str = "";
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Calendar date = Calendar.getInstance();
date.add(Calendar.MONTH, 1);// 加一个月
date.set(Calendar.DATE, 1);// 把日期设置为当月第一天
date.roll(Calendar.DATE, -1);// 日期回滚一天，也就是本月最后一天
str = sdf.format(date.getTime());
return str;
}
//---------------------------------------------------------
//获得今天是这个月的第几周
public static int getWeekOfMonth() {
return calendar.get(Calendar.DAY_OF_WEEK_IN_MONTH);
}
//获得当前年份
public static int getYear() {
return calendar.get(Calendar.YEAR);
}
//获得当前年份
public static int getMonth() {
return calendar.get(Calendar.MONTH) + 1;
}
//获得今天在本年的第几天
public static int getDayOfYear() {
return calendar.get(Calendar.DAY_OF_YEAR);
}
//获得今天在本月的第几天(获得当前日)
public static int getDayOfMonth() {
return calendar.get(Calendar.DAY_OF_MONTH);
}
//获得今天在本周的第几天
public static int getDayOfWeek() {
return calendar.get(Calendar.DAY_OF_WEEK);
}
//得到二个日期间的间隔天数
public static String getTwoDay(String sj1, String sj2) {
SimpleDateFormat myFormatter = new SimpleDateFormat("yyyy-MM-dd");
long day = 0;
try {
java.util.Date date = myFormatter.parse(sj1);
java.util.Date mydate = myFormatter.parse(sj2);
day = (date.getTime() - mydate.getTime()) / (24 * 60 * 60 * 1000);
} catch (Exception e) {
return "";
}
return day + "";
}
//获得半年后的日期
public static Date getTimeYearNext() {
calendar.add(Calendar.DAY_OF_YEAR, 183);
return calendar.getTime();
}
public static String convertDateToString(Date dateTime){
SimpleDateFormat df=new SimpleDateFormat("yyyy-MM-dd");
return df.format(dateTime);
}
//---------------------------------------------------------------
private int getYearPlus() {
Calendar cd = Calendar.getInstance();
int yearOfNumber = cd.get(Calendar.DAY_OF_YEAR);// 获得当天是一年中的第几天
cd.set(Calendar.DAY_OF_YEAR, 1);// 把日期设为当年第一天
cd.roll(Calendar.DAY_OF_YEAR, -1);// 把日期回滚一天。
int MaxYear = cd.get(Calendar.DAY_OF_YEAR);
if (yearOfNumber == 1) {
return -MaxYear;
} else {
return 1 - yearOfNumber;
}
}
// 获得本年第一天的日期
public String getCurrentYearFirst() {
int yearPlus = this.getYearPlus();
GregorianCalendar currentDate = new GregorianCalendar();
currentDate.add(GregorianCalendar.DATE, yearPlus);
Date yearDay = currentDate.getTime();
DateFormat df = DateFormat.getDateInstance();
String preYearDay = df.format(yearDay);
return preYearDay;
}
// 获得本年最后一天的日期 *
public String getCurrentYearEnd() {
Date date = new Date();
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy");// 可以方便地修改日期格式
String years = dateFormat.format(date);
return years + "-12-31";
}
// 获得上年第一天的日期 *
public String getPreviousYearFirst() {
Date date = new Date();
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy");// 可以方便地修改日期格式
String years = dateFormat.format(date);
int years_value = Integer.parseInt(years);
years_value--;
return years_value + "-1-1";
}
// 获得上年最后一天的日期
public String getPreviousYearEnd() {
weeks--;
int yearPlus = this.getYearPlus();
GregorianCalendar currentDate = new GregorianCalendar();
currentDate.add(GregorianCalendar.DATE, yearPlus + MaxYear * weeks
+ (MaxYear - 1));
Date yearDay = currentDate.getTime();
DateFormat df = DateFormat.getDateInstance();
String preYearDay = df.format(yearDay);
return preYearDay;
}
// 获得明年最后一天的日期
public String getNextYearEnd() {
String str = "";
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Calendar lastDate = Calendar.getInstance();
lastDate.add(Calendar.YEAR, 1);// 加一个年
lastDate.set(Calendar.DAY_OF_YEAR, 1);
lastDate.roll(Calendar.DAY_OF_YEAR, -1);
str = sdf.format(lastDate.getTime());
return str;
}
// 获得明年第一天的日期
public String getNextYearFirst() {
String str = "";
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Calendar lastDate = Calendar.getInstance();
lastDate.add(Calendar.YEAR, 1);// 加一个年
lastDate.set(Calendar.DAY_OF_YEAR, 1);
str = sdf.format(lastDate.getTime());
return str;
}
// 获得本季度第一天
public String getThisSeasonFirstTime() {
int month = calendar.get(Calendar.MONTH) + 1;
int array[][] = { { 1, 2, 3 }, { 4, 5, 6 }, { 7, 8, 9 }, { 10, 11, 12 } };
int season = 1;
if (month >= 1 && month <= 3) {
season = 1;
}
if (month >= 4 && month <= 6) {
season = 2;
}
if (month >= 7 && month <= 9) {
season = 3;
}
if (month >= 10 && month <= 12) {
season = 4;
}
int start_month = array[season - 1][0];
int end_month = array[season - 1][2];
Date date = new Date();
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy");// 可以方便地修改日期格式
String years = dateFormat.format(date);
int years_value = Integer.parseInt(years);
int start_days = 1;
// years+"-"+String.valueOf(start_month)+"-1";//getLastDayOfMonth(years_value,start_month);
int end_days = getLastDayOfMonth(years_value, end_month);
String seasonDate = years_value + "-" + start_month + "-" + start_days;
return seasonDate;
}
// 获得本季度最后一天
public String getThisSeasonFinallyTime() {
int month =calendar.get(Calendar.MONTH) + 1;
int array[][] = { { 1, 2, 3 }, { 4, 5, 6 }, { 7, 8, 9 }, { 10, 11, 12 } };
int season = 1;
if (month >= 1 && month <= 3) {
season = 1;
}
if (month >= 4 && month <= 6) {
season = 2;
}
if (month >= 7 && month <= 9) {
season = 3;
}
if (month >= 10 && month <= 12) {
season = 4;
}
int start_month = array[season - 1][0];
int end_month = array[season - 1][2];
Date date = new Date();
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy");// 可以方便地修改日期格式
String years = dateFormat.format(date);
int years_value = Integer.parseInt(years);
int start_days = 1;// years+"-"+String.valueOf(start_month)+"-1";//getLastDayOfMonth(years_value,start_month);
int end_days = getLastDayOfMonth(years_value, end_month);
String seasonDate = years_value + "-" + end_month + "-" + end_days;
return seasonDate;
}
//------------------------------------------------------------------------------
//根据一个日期，返回是星期几的字符串
public static String getWeek(String sdate) {
// 再转换为时间
Date date = CalendarUtil.strToDate(sdate);
Calendar c = Calendar.getInstance();
c.setTime(date);
// int hour=c.get(Calendar.DAY_OF_WEEK);
// hour中存的就是星期几了，其范围 1~7
// 1=星期日 7=星期六，其他类推
return new SimpleDateFormat("EEEE").format(c.getTime()); //EEEE代表星期几
}
//将短时间格式字符串转换为时间 yyyy-MM-dd
public static Date strToDate(String strDate) {
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
ParsePosition pos = new ParsePosition(0);
Date strtodate = formatter.parse(strDate, pos);
return strtodate;
}
/* private int getMonthPlus() {
Calendar cd = Calendar.getInstance();
int monthOfNumber = cd.get(Calendar.DAY_OF_MONTH);
cd.set(Calendar.DATE, 1);// 把日期设置为当月第一天
cd.roll(Calendar.DATE, -1);// 日期回滚一天，也就是最后一天
MaxDate = cd.get(Calendar.DATE);
if (monthOfNumber == 1) {
return -MaxDate;
} else {
return 1 - monthOfNumber;
}
} */
// 获得本年有多少天
private int getMaxYear() {
Calendar cd = Calendar.getInstance();
cd.set(Calendar.DAY_OF_YEAR, 1);// 把日期设为当年第一天
cd.roll(Calendar.DAY_OF_YEAR, -1);// 把日期回滚一天。
int MaxYear = cd.get(Calendar.DAY_OF_YEAR);
return MaxYear;
}
//获取某年某月的最后一天
private int getLastDayOfMonth(int year, int month) {
if (month == 1 || month == 3 || month == 5 || month == 7 || month == 8
|| month == 10 || month == 12) {
return 31;
}
if (month == 4 || month == 6 || month == 9 || month == 11) {
return 30;
}
if (month == 2) {
if (isLeapYear(year)) {
return 29;//闰年
} else {
return 28; //平年
}
}
return 0;
}
/**
* 计算闰年和平年
* 闰年二月是29天，但不是能被4整除的就是闰年
* @param year
* @return
*/
private boolean isLeapYear(int year) {
boolean ison = true;
if((year%4==0&&year%100!=0)||year%400==0) {
ison = true;//闰年
}else {
ison = false;//平年
}
return ison;
}
//系统当前时间
public static String getCurrentDate (){
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
return sdf.format(calendar.getTime());
}
//得到几天前的时间
public static String getDateBefore(String d,int day){
Calendar date =Calendar.getInstance();
Date dd = strToDate(d);
date.setTime(dd);
date.set(Calendar.DATE,date.get(Calendar.DATE)-day);
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
return sdf.format(date.getTime());
}
/* //得到几天后的时间
public static Date getDateAfter(Date d,int day){
Calendar now =Calendar.getInstance();
now.setTime(d);
now.set(Calendar.DATE,now.get(Calendar.DATE)+day);
return now.getTime();
} */
//计算月份差
public static int getMonthSpace(String firstTime,String lastTime) {
SimpleDateFormat sdf =new SimpleDateFormat("yyyy-MM-dd");
Calendar c1 = Calendar.getInstance();
Calendar c2 = Calendar.getInstance();
try {
c1.setTime(sdf.parse(lastTime));
c2.setTime(sdf.parse(firstTime));
} catch (ParseException e) {
e.printStackTrace();
}
int result =(c1.get(Calendar.YEAR)-c2.get(Calendar.YEAR))*12+(c1.get(Calendar.MONTH)-c2.get(Calendar.MONTH));
return result ==0 ? 1 : result;
}
}
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