下面列出了java.util.Calendar#setFirstDayOfWeek ( ) 实例代码，或者点击链接到github查看源代码，也可以在右侧发表评论。
/**
* returns a date based on a week number
*
* @param year The year of the date
* @param week The week of the date
* @param calendar The calendar used to calculate the date
* @param firstDayOfWeek The first day of the week
* @return The Date of the week
*/
private Date getDateTimeFromWeek(int year, int week, Calendar calendar, Integer firstDayOfWeek)
throws IllegalArgumentException {
if (week < 1 || week > 53) {
throw new IllegalArgumentException("The week number is outside the year week range.");
}
calendar.setFirstDayOfWeek(firstDayOfWeek);
calendar.setMinimalDaysInFirstWeek(4);
calendar.set(Calendar.YEAR, year);
calendar.set(Calendar.WEEK_OF_YEAR, week);
calendar.set(Calendar.DAY_OF_WEEK, firstDayOfWeek);
calendar.set(Calendar.HOUR_OF_DAY, 10);
return calendar.getTime();
}
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();
}
public static Object yearOfDateISO8601( IValueMeta metaA, Object dataA ) throws HopValueException {
if ( dataA == null ) {
return null;
}
Calendar calendar = Calendar.getInstance( Locale.ENGLISH );
calendar.setMinimalDaysInFirstWeek( 4 );
calendar.setFirstDayOfWeek( Calendar.MONDAY );
calendar.setTime( metaA.getDate( dataA ) );
int week = calendar.get( Calendar.WEEK_OF_YEAR );
int month = calendar.get( Calendar.MONTH );
int year = calendar.get( Calendar.YEAR );
// fix up for the year taking into account ISO8601 weeks
if ( week >= 52 && month == 0 ) {
year--;
}
if ( week <= 2 && month == 11 ) {
year++;
}
return new Long( year );
}
public static boolean isThisWeek(Calendar date){
Calendar today = Calendar.getInstance();
date.setFirstDayOfWeek(Calendar.MONDAY);
today.setFirstDayOfWeek(Calendar.MONDAY);
return date.get(Calendar.YEAR) == today.get(Calendar.YEAR)
&& date.get(Calendar.WEEK_OF_YEAR) == today.get(Calendar.WEEK_OF_YEAR);
}
@Override
public String format(DateTime timestamp) {
Calendar c = Calendar.getInstance(timestamp.getZone().toTimeZone(), LOCALE);
c.setFirstDayOfWeek(Calendar.SUNDAY);
c.setMinimalDaysInFirstWeek(7);
c.setTimeInMillis(timestamp.getMillis());
int week = c.get(Calendar.WEEK_OF_YEAR);
int weekYear = c.getWeekYear();
int year = c.get(Calendar.YEAR);
if (weekYear < year) {
// get weeks from last year
c.add(Calendar.DAY_OF_MONTH, -7);
week = c.getWeeksInWeekYear();
}
return zeroPadded(2, String.valueOf(week));
}
/**
* 获取当前日期当前一周的开始日期 （周日）
*/
public static String getCurrentWeekFirstDayByDate(String date) {
int year = Integer.parseInt(date.substring(0, 4));
int month = Integer.parseInt(date.substring(4, 6));
int day = Integer.parseInt(date.substring(6));
Calendar calendar = Calendar.getInstance();
calendar.set(year, month - 1, day);
Date newdate = calendar.getTime();
SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd");
Calendar cal = Calendar.getInstance();
cal.setTime(newdate);
int dayWeek = cal.get(Calendar.DAY_OF_WEEK);//获得当前日期是一个星期的第几天
if (1 == dayWeek) {
cal.add(Calendar.DAY_OF_MONTH, -1);
}
cal.setFirstDayOfWeek(Calendar.SUNDAY);//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
int s = cal.get(Calendar.DAY_OF_WEEK);//获得当前日期是一个星期的第几天
cal.add(Calendar.DATE, cal.getFirstDayOfWeek() - s);//根据日历的规则，给当前日期减往星期几与一个星期第一天的差值
String imptimeBegin = sdf.format(cal.getTime());
// System.out.println("所在周星期日的日期："+imptimeBegin);
return imptimeBegin;
}
@Override
public String format(DateTime timestamp) {
Calendar c = Calendar.getInstance(timestamp.getZone().toTimeZone(), LOCALE);
c.setFirstDayOfWeek(Calendar.MONDAY);
c.setMinimalDaysInFirstWeek(4);
c.setTimeInMillis(timestamp.getMillis());
int week = c.get(Calendar.WEEK_OF_YEAR);
int weekYear = c.getWeekYear();
int year = c.get(Calendar.YEAR);
if (weekYear < year) {
// get weeks from last year
c.add(Calendar.DAY_OF_MONTH, -7);
week = c.getWeeksInWeekYear();
}
return zeroPadded(2, String.valueOf(week));
}
/**
* 获取指定時間一周的日期列表
*
* @param date
* @return
*/
public static Date[] getWeek(Date date) {
Date[] dates = new Date[7];
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
calendar.setFirstDayOfWeek(Calendar.MONDAY);
calendar.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
for (int i = 0; i < 7; i++) {
dates[i] = calendar.getTime();
calendar.add(Calendar.DAY_OF_YEAR, 1);
}
return dates;
}
/**
* 4080631: Calendar.hashCode is amazingly bad
*/
public void Test4080631() {
Calendar cal = Calendar.getInstance();
int h1 = cal.hashCode();
cal.add(SECOND, +1);
int h2 = cal.hashCode();
Calendar cal2 = (Calendar) cal.clone();
cal.add(MILLISECOND, +1);
int h3 = cal.hashCode();
logln("hash code: h1=" + h1 + ", h2=" + h2 + ", h3=" + h3);
if (h1 == h2 || h1 == h3 || h2 == h3) {
errln("hash code is poor: hashCode=" + h1);
}
h2 = cal2.hashCode();
cal.add(MILLISECOND, -1);
int h4 = cal.hashCode();
logln("hash code: h2=" + h2 + ", h4=" + h4);
if (cal.equals(cal2) && h2 != h4) {
errln("broken hash code: h2=" + h2 + ", h4=" + h4);
}
int x = cal.getFirstDayOfWeek() + 3;
if (x > SATURDAY) {
x -= 7;
}
cal.setFirstDayOfWeek(x);
int h5 = cal.hashCode();
logln("hash code: h4=" + h4 + ", h5=" + h5);
if (h4 == h5) {
errln("has code is poor with first day of week param: hashCode=" + h4);
}
}
/**
* 获取日期在一年中的周数
* 结果从1开始
* @param dateString yyyy-mm-dd
* @return
* @throws Exception
*/
public int getWeekNumOfYear( String dateString ) throws Exception{
Date date = getDateFromString( dateString , "yyyy-MM-dd");
Calendar cal = Calendar.getInstance();
cal.setTime(date);
cal.setFirstDayOfWeek(2); //设置每周的第一天是星期一
return cal.get(Calendar.WEEK_OF_YEAR);
}
public static Date getFirstDayOfWeek(Date date) {
Calendar c = new GregorianCalendar();
c.setFirstDayOfWeek(Calendar.MONDAY);
c.setTime(date);
c.set(Calendar.DAY_OF_WEEK, c.getFirstDayOfWeek()); // Monday
return c.getTime();
}
private void setFirstDayOfWeekAndMinimalDaysInFirstWeek(Calendar startCalendar, int weekStartDay) {
startCalendar.getTime();
startCalendar.setFirstDayOfWeek(weekStartDay);
startCalendar.setMinimalDaysInFirstWeek(4);
startCalendar.set(Calendar.DAY_OF_WEEK, weekStartDay);
}
/**
* 取得指定日期所在周的最后一天
*/
public static Date getLastDayOfWeek(Date date) {
Calendar c = Calendar.getInstance();
c.setFirstDayOfWeek(Calendar.SUNDAY);
c.setTime(date);
c.set(Calendar.DAY_OF_WEEK, c.getFirstDayOfWeek() + 6); // Sunday
return c.getTime();
}
public String getStartOfWeek(String dateString) throws Exception{
SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
Date date = format.parse(dateString);
Calendar cal = Calendar.getInstance();
cal.setTime(date);
cal.setFirstDayOfWeek(Calendar.MONDAY);
int tmp = cal.get(Calendar.DAY_OF_WEEK) - 1;
if (0 == tmp) {
tmp = 7;
}
cal.add(Calendar.DATE, -(tmp-1));
return getDateStringFromDate(cal.getTime(), "yyyy-MM-dd") + " 00:00:00";
}
private int getWeekCountBasedOnMode() {
int weekCount = calendarMode.visibleWeeksCount;
boolean isInMonthsMode = calendarMode.equals(CalendarMode.MONTHS);
if (isInMonthsMode && mDynamicHeightEnabled && adapter != null && pager != null) {
Calendar cal = (Calendar) adapter.getItem(pager.getCurrentItem()).getCalendar().clone();
cal.set(Calendar.DAY_OF_MONTH, cal.getActualMaximum(Calendar.DAY_OF_MONTH));
//noinspection ResourceType
cal.setFirstDayOfWeek(getFirstDayOfWeek());
weekCount = cal.get(Calendar.WEEK_OF_MONTH);
}
return weekCount + DAY_NAMES_ROW;
}
/**
* Gets the week start time with the specified time.
*
* @param time the specified time
* @return week start time
*/
public static long getWeekStartTime(final long time) {
final Calendar start = Calendar.getInstance();
start.setFirstDayOfWeek(Calendar.MONDAY);
start.setTimeInMillis(time);
start.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
start.set(Calendar.HOUR, 0);
start.set(Calendar.MINUTE, 0);
start.set(Calendar.SECOND, 0);
start.set(Calendar.MILLISECOND, 0);
return start.getTime().getTime();
}
/**
* 获取日期在一年中的周数
* 结果从1开始
* @param dateString yyyy-mm-dd
* @return
*/
public int getWeekNumOfYear( Date date ){
try {
Calendar cal = Calendar.getInstance();
cal.setTime(date);
cal.setFirstDayOfWeek(2);//设置每周的第一天是星期一
return cal.get( Calendar.WEEK_OF_YEAR );
} catch (Exception e) {
logger.warn( "系统getWeekNumOfYear发生异常");
logger.error(e);
}
return -1;
}
public String getEndOfWeek(String dateString) throws Exception{
Date date = getDateFromString(getStartOfWeek(dateString), "yyyy-MM-dd HH:mm:ss");
Calendar cal = Calendar.getInstance();
cal.setTime(date);
cal.setFirstDayOfWeek(Calendar.MONDAY);
cal.add(Calendar.DATE, 6);
return getDateStringFromDate(cal.getTime(), "yyyy-MM-dd") + " 23:59:59";
}
private void setDateSpanStartAndEnd(Instant time)
{
Calendar calendar = new GregorianCalendar();
calendar.setTimeInMillis(time.toEpochMilli());
calendar.setFirstDayOfWeek(Calendar.SUNDAY);
Integer dateSpanField = -1;
if (dateSpanUnit.equals(YEAR))
{
// Roll the year back to the beginning (midnight of the first of the year).
dateSpanField = Calendar.YEAR;
calendar.set(Calendar.MONTH, Calendar.JANUARY);
calendar.set(Calendar.WEEK_OF_MONTH, 1);
calendar.set(Calendar.DAY_OF_MONTH, 1);
}
if (dateSpanUnit.equals(MONTH))
{
// Roll the month back to the beginning (midnight of the first of the month).
dateSpanField = Calendar.MONTH;
calendar.set(Calendar.WEEK_OF_MONTH, 1);
calendar.set(Calendar.DAY_OF_MONTH, 1);
}
if (dateSpanUnit.equals(WEEK))
{
// Roll the week back to the beginning (midnight Sunday).
dateSpanField = Calendar.WEEK_OF_YEAR;
calendar.set(Calendar.DAY_OF_WEEK, Calendar.SUNDAY);
}
if (dateSpanUnit.equals(DAY))
dateSpanField = Calendar.DATE;
// Roll the day back to midnight
calendar.set(Calendar.HOUR_OF_DAY, 0);
calendar.set(Calendar.MINUTE, 0);
calendar.set(Calendar.SECOND, 0);
calendar.set(Calendar.MILLISECOND, 0);
spanStart = calendar.toInstant();
calendar.add(dateSpanField, dateSpanValue);
spanEnd = calendar.toInstant();
}
/**
* Return if the date given is a first day of week
*
* @param year
* The year of the date.
* @param month
* The month of the date.
* @param day
* The day of the date.
* @return true or false
*/
@SuppressLint("WrongConstant") public static boolean isFirstDayOfWeek(int year, int month, int day) {
Calendar calendar = Calendar.getInstance();
calendar.set(year, month - 1, day);
calendar.add(Calendar.SECOND, 0);
calendar.setFirstDayOfWeek(Calendar.SUNDAY);
return calendar.get(Calendar.DAY_OF_WEEK) == 1;
}