Java 日期时间格式化显示一年中的第几周1

import java.util.Calendar;

public class GetWeekOfMonthAndYear {
   public static void main(String[] args) {
      Calendar cal = Calendar.getInstance();
      System.out.println("Current week of month is : " +cal.get(Calendar.WEEK_OF_MONTH));
      System.out.println("Current week of year is : " +cal.get(Calendar.WEEK_OF_YEAR));
      cal.add(Calendar.WEEK_OF_MONTH, 1);
      System.out.println(
         "date after one year : " + (cal.get(Calendar.MONTH) + 1)+ "-"+ cal.get(Calendar.DATE)+ "-"+ cal.get(Calendar.YEAR));
   }
}