下面列出了java.util.GregorianCalendar#isLeapYear ( ) 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。
private void checkBirthday(int year, int month, int day) {
var charactersData = getDAO(PlayerDAO.class).findBirthdayCharacters(year, month, day);
charactersData.forEach(characterData -> {
var name = PlayerNameTable.getInstance().getNameById(characterData.getCharId());
if(isNull(name)) {
return;
}
var age = year - characterData.getCreateDate().getYear();
var text = Config.ALT_BIRTHDAY_MAIL_TEXT.replace("$c1", name).replace("$s1", String.valueOf(age));
final var mail = MailData.of(characterData.getCharId(), Config.ALT_BIRTHDAY_MAIL_SUBJECT, text, MailType.BIRTHDAY);
final Attachment attachments = new Attachment(mail.getSender(), mail.getId());
attachments.addItem("Birthday", Config.ALT_BIRTHDAY_GIFT, 1, null, null);
mail.attach(attachments);
MailEngine.getInstance().sendMail(mail);
_count++;
});
// If character birthday is 29-Feb and year isn't leap, send gift on 28-feb
final GregorianCalendar calendar = new GregorianCalendar();
if ((month == Calendar.FEBRUARY) && (day == 28) && !calendar.isLeapYear(_today.get(Calendar.YEAR))) {
checkBirthday(year, month, 29);
}
}
/**
* Check isLeapYear for BC years.
*/
public void Test4125881() {
Locale locale = Locale.getDefault();
if (!TestUtils.usesGregorianCalendar(locale)) {
logln("Skipping this test because locale is " + locale);
return;
}
GregorianCalendar cal = (GregorianCalendar) Calendar.getInstance();
DateFormat fmt = new SimpleDateFormat("MMMM d, yyyy G");
cal.clear();
for (int y = -20; y <= 10; ++y) {
cal.set(ERA, y < 1 ? GregorianCalendar.BC : GregorianCalendar.AD);
cal.set(YEAR, y < 1 ? 1 - y : y);
logln(y + " = " + fmt.format(cal.getTime()) + " "
+ cal.isLeapYear(y));
if (cal.isLeapYear(y) != ((y + 40) % 4 == 0)) {
errln("Leap years broken");
}
}
}
/**
* Prove that GregorianCalendar is proleptic (it used to cut off
* at 45 BC, and not have leap years before then).
*/
public void Test4125892() {
Locale locale = Locale.getDefault();
if (!TestUtils.usesGregorianCalendar(locale)) {
logln("Skipping this test because locale is " + locale);
return;
}
GregorianCalendar cal = (GregorianCalendar) Calendar.getInstance();
DateFormat fmt = new SimpleDateFormat("MMMM d, yyyy G");
cal.clear();
cal.set(ERA, GregorianCalendar.BC);
cal.set(YEAR, 81); // 81 BC is a leap year (proleptically)
cal.set(MONTH, FEBRUARY);
cal.set(DATE, 28);
cal.add(DATE, 1);
if (cal.get(DATE) != 29
|| !cal.isLeapYear(-80)) { // -80 == 81 BC
errln("Calendar not proleptic");
}
}
/**
* Reported bug is that a GregorianCalendar with a cutover of Date(Long.MAX_VALUE)
* doesn't behave as a pure Julian calendar.
* CANNOT REPRODUCE THIS BUG
*/
public void Test4149677() {
TimeZone[] zones = {TimeZone.getTimeZone("GMT"),
TimeZone.getTimeZone("PST"),
TimeZone.getTimeZone("EAT")};
for (int i = 0; i < zones.length; ++i) {
GregorianCalendar calendar = new GregorianCalendar(zones[i]);
// Make sure extreme values don't wrap around
calendar.setTime(new Date(Long.MIN_VALUE));
if (calendar.get(ERA) != GregorianCalendar.BC) {
errln("Fail: Date(Long.MIN_VALUE) has an AD year in " + zones[i]);
}
calendar.setTime(new Date(Long.MAX_VALUE));
if (calendar.get(ERA) != GregorianCalendar.AD) {
errln("Fail: Date(Long.MAX_VALUE) has a BC year in " + zones[i]);
}
calendar.setGregorianChange(new Date(Long.MAX_VALUE));
// to obtain a pure Julian calendar
boolean is100Leap = calendar.isLeapYear(100);
if (!is100Leap) {
errln("test failed with zone " + zones[i].getID());
errln(" cutover date is Date(Long.MAX_VALUE)");
errln(" isLeapYear(100) returns: " + is100Leap);
}
}
}
/**
* 获取任意两个日期间的天数
* @param tStartDate 起始日期,
* @param tEndDate 结束日期
* @return 天数
*/
public static int getDayCount(Date tStartDate, Date tEndDate) {
int iRetVal = 0;
GregorianCalendar calendar = (GregorianCalendar) GregorianCalendar.
getInstance();
calendar.setTime(tStartDate);
GregorianCalendar calendar2 = (GregorianCalendar) GregorianCalendar.
getInstance();
calendar2.setTime(tEndDate);
int iMaxDays = 0;
while (calendar.before(calendar2)) {
if (calendar.isLeapYear(calendar.get(GregorianCalendar.YEAR))) {
iMaxDays = 366;
} else {
iMaxDays = 365;
}
++iRetVal;
calendar.roll(GregorianCalendar.DAY_OF_YEAR, true);
if (calendar.get(GregorianCalendar.DAY_OF_YEAR) == iMaxDays) {
calendar.roll(GregorianCalendar.YEAR, 1);
calendar.set(GregorianCalendar.MONTH, GregorianCalendar.JANUARY);
calendar.set(GregorianCalendar.DAY_OF_MONTH, 1);
}
}
return iRetVal;
}
private static int determineDays(Calendar _cal) {
int month = _cal.get(Calendar.MONTH);
if (month == 8 || month == 3 || month == 5 || month == 10)
return 30;
else if (month == 1) {
GregorianCalendar greg = new GregorianCalendar(_cal.get(Calendar.YEAR), _cal.get(Calendar.MONTH), _cal.get(Calendar.DATE));
if (greg.isLeapYear(greg.get(Calendar.YEAR)))
return 29;
else
return 28;
} else
return 31;
}
public static double dateToDecimalYear(GregorianCalendar cal){
int days = cal.get( Calendar.DAY_OF_YEAR );
double year = cal.get(Calendar.YEAR);
double dayFrac;
if ( cal.isLeapYear((int)year) ) {
dayFrac = ( double ) days / 366;
} else {
dayFrac = ( double ) days / 365;
}
return year + dayFrac;
}
public static Date decimalYearToDate(double year){
int yr = (int) year;
double days;
GregorianCalendar cal = new GregorianCalendar(yr, Calendar.JANUARY, 1);
if ( cal.isLeapYear(yr)) {
days = (year - yr) * 366;
} else {
days = (year - yr) * 365;
}
cal.add(Calendar.DATE, (int)days);//Math.ceil(days));
return cal.getTime();
}
/**
* 验证15位身份证的合法性,该方法验证不准确，最好是将15转为18位后再判断，该类中已提供。
*
* @param idcard idcard
* @return return
*/
public static boolean validate15(String idcard) {
// 非15位为假
if (idcard.length() != 15) {
return false;
}
// 是否全都为数字
if (isDigital(idcard)) {
String provinceid = idcard.substring(0, 2);
String birthday = idcard.substring(6, 12);
int year = Integer.parseInt(idcard.substring(6, 8));
int month = Integer.parseInt(idcard.substring(8, 10));
int day = Integer.parseInt(idcard.substring(10, 12));
// 判断是否为合法的省份
boolean flag = false;
for (String id : CITY_CODE) {
if (id.equals(provinceid)) {
flag = true;
break;
}
}
if (!flag) {
return false;
}
// 该身份证生出日期在当前日期之后时为假
Date birthdate = null;
try {
birthdate = new SimpleDateFormat("yyMMdd").parse(birthday);
} catch (ParseException e) {
e.printStackTrace();
}
if (birthdate == null || new Date().before(birthdate)) {
return false;
}
// 判断是否为合法的年份
GregorianCalendar curDay = new GregorianCalendar();
int curYear = curDay.get(Calendar.YEAR);
int year2bit = Integer.parseInt(String.valueOf(curYear)
.substring(2));
// 判断该年份的两位表示法，小于50的和大于当前年份的，为假
if ((year < 50 && year > year2bit)) {
return false;
}
// 判断是否为合法的月份
if (month < 1 || month > 12) {
return false;
}
// 判断是否为合法的日期
boolean mflag = false;
curDay.setTime(birthdate); // 将该身份证的出生日期赋于对象curDay
switch (month) {
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12:
mflag = (day >= 1 && day <= 31);
break;
case 2: // 公历的2月非闰年有28天,闰年的2月是29天。
if (curDay.isLeapYear(curDay.get(Calendar.YEAR))) {
mflag = (day >= 1 && day <= 29);
} else {
mflag = (day >= 1 && day <= 28);
}
break;
case 4:
case 6:
case 9:
case 11:
mflag = (day >= 1 && day <= 30);
break;
}
if (!mflag) {
return false;
}
} else {
return false;
}
return true;
}
/**
* 验证15位身份证的合法性,该方法验证不准确，最好是将15转为18位后再判断，该类中已提供。
*/
public boolean isValidate15Idcard(String idcard) {
// 非15位为假
if (idcard.length() != 15) {
return false;
}
// 是否全都为数字
if (isDigital(idcard)) {
String provinceid = idcard.substring(0, 2);
String birthday = idcard.substring(6, 12);
int year = Integer.parseInt(idcard.substring(6, 8));
int month = Integer.parseInt(idcard.substring(8, 10));
int day = Integer.parseInt(idcard.substring(10, 12));
// 判断是否为合法的省份
boolean flag = false;
for (String id : cityCode) {
if (id.equals(provinceid)) {
flag = true;
break;
}
}
if (!flag) {
return false;
}
// 该身份证生出日期在当前日期之后时为假
Date birthdate = null;
try {
birthdate = new SimpleDateFormat("yyMMdd").parse(birthday);
} catch (ParseException e) {
e.printStackTrace();
}
if (birthdate == null || new Date().before(birthdate)) {
return false;
}
// 判断是否为合法的年份
GregorianCalendar curDay = new GregorianCalendar();
int curYear = curDay.get(Calendar.YEAR);
int year2bit = Integer.parseInt(String.valueOf(curYear).substring(2));
// 判断该年份的两位表示法，小于50的和大于当前年份的，为假
if ((year < 50 && year > year2bit)) {
return false;
}
// 判断是否为合法的月份
if (month < 1 || month > 12) {
return false;
}
// 判断是否为合法的日期
boolean mflag = false;
curDay.setTime(birthdate); // 将该身份证的出生日期赋于对象curDay
switch (month) {
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12:
mflag = (day >= 1 && day <= 31);
break;
case 2: // 公历的2月非闰年有28天,闰年的2月是29天。
if (curDay.isLeapYear(curDay.get(Calendar.YEAR))) {
mflag = (day >= 1 && day <= 29);
} else {
mflag = (day >= 1 && day <= 28);
}
break;
case 4:
case 6:
case 9:
case 11:
mflag = (day >= 1 && day <= 30);
break;
}
if (!mflag) {
return false;
}
} else {
return false;
}
return true;
}
/**
* 验证15位身份证的合法性,该方法验证不准确，最好是将15转为18位后再判断，该类中已提供。
*
* @param idcard
* @return
*/
public boolean isValidate15Idcard(String idcard) {
// 非15位为假
if (idcard.length() != 15) {
return false;
}
// 是否全都为数字
if (isDigital(idcard)) {
String provinceid = idcard.substring(0, 2);
String birthday = idcard.substring(6, 12);
int year = Integer.parseInt(idcard.substring(6, 8));
int month = Integer.parseInt(idcard.substring(8, 10));
int day = Integer.parseInt(idcard.substring(10, 12));
// 判断是否为合法的省份
boolean flag = false;
for (String id : cityCode) {
if (id.equals(provinceid)) {
flag = true;
break;
}
}
if (!flag) {
return false;
}
// 该身份证生出日期在当前日期之后时为假
Date birthdate = null;
try {
birthdate = new SimpleDateFormat("yyMMdd").parse(birthday);
} catch (ParseException e) {
e.printStackTrace();
}
if (birthdate == null || new Date().before(birthdate)) {
return false;
}
// 判断是否为合法的年份
GregorianCalendar curDay = new GregorianCalendar();
int curYear = curDay.get(Calendar.YEAR);
int year2bit = Integer.parseInt(String.valueOf(curYear)
.substring(2));
// 判断该年份的两位表示法，小于50的和大于当前年份的，为假
if ((year < 50 && year > year2bit)) {
return false;
}
// 判断是否为合法的月份
if (month < 1 || month > 12) {
return false;
}
// 判断是否为合法的日期
boolean mflag = false;
curDay.setTime(birthdate); // 将该身份证的出生日期赋于对象curDay
switch (month) {
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12:
mflag = (day >= 1 && day <= 31);
break;
case 2: // 公历的2月非闰年有28天,闰年的2月是29天。
if (curDay.isLeapYear(curDay.get(Calendar.YEAR))) {
mflag = (day >= 1 && day <= 29);
} else {
mflag = (day >= 1 && day <= 28);
}
break;
case 4:
case 6:
case 9:
case 11:
mflag = (day >= 1 && day <= 30);
break;
}
if (!mflag) {
return false;
}
} else {
return false;
}
return true;
}
/** Compute which days to put where, in the Cal panel */
public void print(int mm, int yy) {
/** The number of days to leave blank at the start of this month */
int leadGap = 0;
System.out.print(months[mm]); // print month and year
System.out.print(" ");
System.out.print(yy);
System.out.println();
if (mm < 0 || mm > 11)
throw new IllegalArgumentException("Month " + mm + " bad, must be 0-11");
GregorianCalendar calendar = new GregorianCalendar(yy, mm, 1);
System.out.println("Su Mo Tu We Th Fr Sa");
// Compute how much to leave before the first.
// get(DAY_OF_WEEK) returns 0 for Sunday, which is just right.
leadGap = calendar.get(Calendar.DAY_OF_WEEK)-1;
int daysInMonth = CalUtils.getDaysInMonth(mm);
if (calendar.isLeapYear(calendar.get(Calendar.YEAR)) && mm == 1)
++daysInMonth;
// Blank out the labels before 1st day of month
for (int i = 0; i < leadGap; i++) {
System.out.print(" ");
}
// Fill in numbers for the day of month.
for (int i = 1; i <= daysInMonth; i++) {
// This "if" statement is simpler than fiddling with NumberFormat
if (i<=9)
System.out.print(' ');
System.out.print(i);
if ((leadGap + i) % 7 == 0) // wrap if end of line.
System.out.println();
else
System.out.print(' ');
}
System.out.println();
}
public boolean isLeapYear() {
GregorianCalendar calendar = new GregorianCalendar();
return calendar.isLeapYear(fieldYear);
}
@SuppressWarnings("unused")
public boolean isLeapYear(int year) {
GregorianCalendar calendar = new GregorianCalendar();
return calendar.isLeapYear(year);
}
public boolean isLeapYear() {
GregorianCalendar calendar = new GregorianCalendar();
return calendar.isLeapYear(fieldYear);
}
/**
* Prints Month
*
* @param mm
* @param yy
*/
private void printMonth(int mm, int yy) {
// //JKLog.d(tag, "==> printMonth: mm: " + mm + " " + "yy: " + yy);
// The number of days to leave blank at
// the start of this month.
int trailingSpaces = 0;
int leadSpaces = 0;
int daysInPrevMonth = 0;
int prevMonth = 0;
int prevYear = 0;
int nextMonth = 0;
int nextYear = 0;
int currentMonth = mm - 1;
String currentMonthName = getMonthAsString(currentMonth);
daysInMonth = getNumberOfDaysOfMonth(_calendar);
// //JKLog.d(tag, "Current Month: " + " " + currentMonthName + " having " + daysInMonth + " days.");
// Gregorian Calendar : MINUS 1, set to FIRST OF MONTH
GregorianCalendar cal = new GregorianCalendar(yy, currentMonth, 1);
//JKLog.d(tag, "Gregorian Calendar:= " + cal.getTime().toString());
Calendar prevC = Calendar.getInstance();
if (currentMonth == 11) {
prevMonth = currentMonth - 1;
prevC.set(Calendar.MONTH,prevMonth);
daysInPrevMonth = getNumberOfDaysOfMonth(prevC);
nextMonth = 0;
prevYear = yy;
nextYear = yy + 1;
//JKLog.d(tag, "*->PrevYear: " + prevYear + " PrevMonth:" + prevMonth + " NextMonth: " + nextMonth + " NextYear: " + nextYear);
} else if (currentMonth == 0) {
prevMonth = 11;
prevYear = yy - 1;
nextYear = yy;
prevC.set(Calendar.MONTH,prevMonth);
daysInPrevMonth = getNumberOfDaysOfMonth(prevC);
nextMonth = 1;
//JKLog.d(tag, "**--> PrevYear: " + prevYear + " PrevMonth:" + prevMonth + " NextMonth: " + nextMonth + " NextYear: " + nextYear);
} else {
prevMonth = currentMonth - 1;
nextMonth = currentMonth + 1;
nextYear = yy;
prevYear = yy;
prevC.set(Calendar.MONTH,prevMonth);
daysInPrevMonth = getNumberOfDaysOfMonth(prevC);
//JKLog.d(tag, "***---> PrevYear: " + prevYear + " PrevMonth:" + prevMonth + " NextMonth: " + nextMonth + " NextYear: " + nextYear);
}
// Compute how much to leave before before the first day of the
// month.
// getDay() returns 0 for Sunday.
int currentWeekDay = cal.get(Calendar.DAY_OF_WEEK) - 1;
trailingSpaces = currentWeekDay;
//JKLog.d(tag, "Week Day:" + currentWeekDay + " is " + getWeekDayAsString(currentWeekDay));
//JKLog.d(tag, "No. Trailing space to Add: " + trailingSpaces);
//JKLog.d(tag, "No. of Days in Previous Month: " + daysInPrevMonth);
if (cal.isLeapYear(cal.get(Calendar.YEAR)) && mm == 1) {
++daysInMonth;
}
// Trailing Month days
for (int i = 0; i < trailingSpaces; i++) {
// //JKLog.d(tag, "PREV MONTH:= " + prevMonth + " => " + getMonthAsString(prevMonth) + " " + String.valueOf((daysInPrevMonth - trailingSpaces + DAY_OFFSET) + i));
list.add("GREY-"+ String.valueOf((daysInPrevMonth - trailingSpaces + DAY_OFFSET) + i) + "-" + getMonthAsString(prevMonth) + "-" + prevYear);
}
//紀錄Month是第幾格開始
thisMonthStartIndex = list.size();
// Current Month Days
for (int i = 1; i <= daysInMonth; i++) {
//JKLog.d(currentMonthName, String.valueOf(i) + " " + getMonthAsString(currentMonth) + " " + yy);
if (i == getCurrentDayOfMonth()) {
list.add("BLACK-" + String.valueOf(i) + "-" + getMonthAsString(currentMonth) + "-" + yy);
} else {
list.add("WHITE-" + String.valueOf(i) + "-" + getMonthAsString(currentMonth) + "-" + yy);
}
}
//紀錄Month是第幾格結束
thisMonthEndIndex = list.size();
// Leading Month days
for (int i = 0; i < list.size() % 7; i++) {
//JKLog.d(tag, "NEXT MONTH:= " + getMonthAsString(nextMonth));
list.add( "GREY-" + String.valueOf(i + 1) +"-" + getMonthAsString(nextMonth) + "-" + nextYear);
}
}
public boolean isLeapYearExample(int year) {
GregorianCalendar cal = (GregorianCalendar) GregorianCalendar.getInstance();
return cal.isLeapYear(year);
}
private int days(GregorianCalendar date) {
return date.get(Calendar.MONTH) == 1 ?
(date.isLeapYear(date.get(Calendar.YEAR)) ? 29 : 28) :
DAYS[date.get(Calendar.MONTH)];
}