从java.util.Date获取Year

Question

I have a date column in a Cassandra column family. When I retrieve data from this CF using datastax java API, this date object can be taken as a java.util.Date object.

It has a getYear() method but it is deprecated. The corresponding javadoc says:

As of JDK version 1.1, replaced by Calendar.get(Calendar.YEAR) - 1900.

How can I get the year, month, day attributes from this date object properly?

Answer 1

Could you try like tihs;

      // create a calendar
      Calendar cal = Calendar.getInstance();
      cal.setTime(datetime);  //use java.util.Date object as arguement
      // get the value of all the calendar date fields.
      System.out.println("Calendar's Year: " + cal.get(Calendar.YEAR));
      System.out.println("Calendar's Month: " + cal.get(Calendar.MONTH));
      System.out.println("Calendar's Day: " + cal.get(Calendar.DATE));

As mentioned in javadocs ;

@Deprecated public int getYear() Deprecated. As of JDK version 1.1, replaced by Calendar.get(Calendar.YEAR) - 1900. Returns a value that is the result of subtracting 1900 from the year that contains or begins with the instant in time represented by this Date object, as interpreted in the local time zone. Returns: the year represented by this date, minus 1900.

Answer 2

A good option is to use date format as follows:

SimpleDateFormat sdf1 = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
SimpleDateFormat sdf2 = new SimpleDateFormat("yyyy");
Date             date = sdf1.parse(datetime);
String           year = sdf2.format(date);

Answer 3

use LocalDate object in java8

Date date = new Date();
LocalDate localDate = date.toInstant().atZone(ZoneId.systemDefault()).toLocalDate();
int year  = localDate.getYear();
int month = localDate.getMonthValue();
int day   = localDate.getDayOfMonth();

Answer 4

To retrieve the date & time fields you can use this code:

DateFormat.getDateTimeInstance().getCalendar().get(DateFormat.MONTH_FIELD)

Just replace MONTH_FIELD with one somehting else like "DAY_OF_WEEK_FIELD" to retrieve the day of the week (I think '1' stands for monday) or "MINUTE_FIELD" for the current minute, etc. :)