例如,我有日期:“23/2/2010”(2010年2月23日)。我想把它传递给一个返回星期几的函数。我该怎么做呢?
在这个例子中,函数应该返回String "Tue"。
此外,如果只需要日期顺序,如何检索?
例如,我有日期:“23/2/2010”(2010年2月23日)。我想把它传递给一个返回星期几的函数。我该怎么做呢?
在这个例子中,函数应该返回String "Tue"。
此外,如果只需要日期顺序,如何检索?
当前回答
通过使用java.util.scanner包给用户输入日期、月和年来查找星期几的程序:
import java.util.Scanner;
public class Calender {
public static String getDay(String day, String month, String year) {
int ym, yp, d, ay, a = 0;
int by = 20;
int[] y = new int[]{6, 4, 2, 0};
int[] m = new int []{0, 3, 3, 6, 1, 4, 6, 2, 5, 0, 3, 5};
String[] wd = {"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"};
int gd = Integer.parseInt(day);
int gm = Integer.parseInt(month);
int gy = Integer.parseInt(year);
ym = gy % 100;
yp = ym / 4;
ay = gy / 100;
while (ay != by) {
by = by + 1;
a = a + 1;
if(a == 4) {
a = 0;
}
}
if ((ym % 4 == 0) && (gm == 2)) {
d = (gd + m[gm - 1] + ym + yp + y[a] - 1) % 7;
} else
d = (gd + m[gm - 1] + ym + yp + y[a]) % 7;
return wd[d];
}
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
String day = in.next();
String month = in.next();
String year = in.next();
System.out.println(getDay(day, month, year));
}
}
其他回答
是的。根据具体情况:
You can use java.util.Calendar: Calendar c = Calendar.getInstance(); c.setTime(yourDate); int dayOfWeek = c.get(Calendar.DAY_OF_WEEK); if you need the output to be Tue rather than 3 (Days of week are indexed starting at 1 for Sunday, see Calendar.SUNDAY), instead of going through a calendar, just reformat the string: new SimpleDateFormat("EE").format(date) (EE meaning "day of week, short version") if you have your input as string, rather than Date, you should use SimpleDateFormat to parse it: new SimpleDateFormat("dd/M/yyyy").parse(dateString) you can use joda-time's DateTime and call dateTime.dayOfWeek() and/or DateTimeFormat. edit: since Java 8 you can now use java.time package instead of joda-time
String inputDate = "01/08/2012";
SimpleDateFormat format1 = new SimpleDateFormat("dd/MM/yyyy");
Date dt1 = format1.parse(input_date);
DateFormat format2 = new SimpleDateFormat("EEEE");
String finalDay = format2.format(dt1);
使用此代码从输入日期中查找日期名称。简单且经过良好测试。
import java.text.SimpleDateFormat;
import java.util.Scanner;
class DayFromDate {
public static void main(String args[]) {
System.out.println("Enter the date(dd/mm/yyyy):");
Scanner scan = new Scanner(System.in);
String Date = scan.nextLine();
try {
boolean dateValid = dateValidate(Date);
if(dateValid == true) {
SimpleDateFormat df = new SimpleDateFormat( "dd/MM/yy" );
java.util.Date date = df.parse( Date );
df.applyPattern( "EEE" );
String day= df.format( date );
if(day.compareTo("Sat") == 0 || day.compareTo("Sun") == 0) {
System.out.println(day + ": Weekend");
} else {
System.out.println(day + ": Weekday");
}
} else {
System.out.println("Invalid Date!!!");
}
} catch(Exception e) {
System.out.println("Invalid Date Formats!!!");
}
}
static public boolean dateValidate(String d) {
String dateArray[] = d.split("/");
int day = Integer.parseInt(dateArray[0]);
int month = Integer.parseInt(dateArray[1]);
int year = Integer.parseInt(dateArray[2]);
System.out.print(day + "\n" + month + "\n" + year + "\n");
boolean leapYear = false;
if((year % 4 == 0) && (year % 100 != 0) || (year % 400 == 0)) {
leapYear = true;
}
if(year > 2099 || year < 1900)
return false;
if(month < 13) {
if(month == 1 || month == 3 || month == 5 || month == 7 || month == 8 || month == 10 || month == 12) {
if(day > 31)
return false;
} else if(month == 4 || month == 6 || month == 9 || month == 11) {
if(day > 30)
return false;
} else if(leapYear == true && month == 2) {
if(day > 29)
return false;
} else if(leapYear == false && month == 2) {
if(day > 28)
return false;
}
return true;
} else return false;
}
}
Calendar cal = Calendar.getInstance(desired date);
cal.setTimeInMillis(System.currentTimeMillis());
int dayOfWeek = cal.get(Calendar.DAY_OF_WEEK);
通过提供当前时间戳获取日值。
...
import java.time.LocalDate;
...
//String month = in.next();
int mm = in.nextInt();
//String day = in.next();
int dd = in.nextInt();
//String year = in.next();
int yy = in.nextInt();
in.close();
LocalDate dt = LocalDate.of(yy, mm, dd);
System.out.print(dt.getDayOfWeek());