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
为今天找一个日期,然后从中找出一个星期。
LocalDate d = java.time.LocalDate.now();
System.out.println(java.time.LocalDate.now());
Calendar c = Calendar.getInstance();
int dayOfWeek = c.get(Calendar.DAY_OF_WEEK);
System.out.println(dayOfWeek);
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
简单地使用SimpleDateFormat。
SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy", java.util.Locale.ENGLISH);
Date myDate = sdf.parse("28/12/2013");
sdf.applyPattern("EEE, d MMM yyyy");
String sMyDate = sdf.format(myDate);
结果是:2013年12月28日星期六
默认构造函数接受“默认”区域设置,因此在需要特定模式时要小心使用它。
public SimpleDateFormat(String pattern) {
this(pattern, Locale.getDefault(Locale.Category.FORMAT));
}
你可以使用下面的方法通过传递一个特定的日期来获取星期几,
这里对于Calendar类的set方法,难点在于month参数的索引将从0开始。
public static String getDay(int day, int month, int year) {
Calendar cal = Calendar.getInstance();
if(month==1){
cal.set(year,0,day);
}else{
cal.set(year,month-1,day);
}
int dow = cal.get(Calendar.DAY_OF_WEEK);
switch (dow) {
case 1:
return "SUNDAY";
case 2:
return "MONDAY";
case 3:
return "TUESDAY";
case 4:
return "WEDNESDAY";
case 5:
return "THURSDAY";
case 6:
return "FRIDAY";
case 7:
return "SATURDAY";
default:
System.out.println("GO To Hell....");
}
return null;
}
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.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());