JAVA日期处理相关

 package javaapplication1;
import java.text.*;
import java.util.*;
public class Spell_Time {
     //给定一个日期，获得这个日期所在周的周一的日期
     //输入参数：String date
     //-----------------------------------------------------
     public static String getMonday(String date) {
         SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
         Date d = null;
         try {
             d = format.parse(date);
         } catch(Exception e) {
             e.printStackTrace();
         }
         Calendar cal = Calendar.getInstance();
         cal.setTime(d);
         cal.set(Calendar.DAY_OF_WEEK,Calendar.MONDAY);
         return format.format(cal.getTime());
     }
    
     //给定一个日期，获得这个日期所在周的周日的日期
     //输入参数：String date
     //-----------------------------------------------------
     public static String getSunday(String date) {
         SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
         Date d = null;
         try {
             d = format.parse(date);
         } catch(Exception e) {
             e.printStackTrace();
         }
         Calendar cal = Calendar.getInstance();
         cal.setTime(d);
         cal.add(cal.WEEK_OF_YEAR,1);
         cal.set(Calendar.DAY_OF_WEEK,Calendar.SUNDAY);
         return format.format(cal.getTime());
     }
    
     //给定一个日期和天数，获得这个相加后的日期
     //输入参数：String date,int iday
     //-----------------------------------------------------
     public static String addDay(String date,int iday) {
         SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
         Date d = null;
         try {
             d = format.parse(date);
         } catch(Exception e) {
             e.printStackTrace();
         }
         Calendar cal = Calendar.getInstance();
         cal.setTime(d);
         cal.add(cal.DAY_OF_YEAR,iday);
         return format.format(cal.getTime());
     }
    
     //取得今天的 YY-MM-DD格式
     //-----------------------------------------------------
     public static String getToday() {
         SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
         java.util.Date d = new java.util.Date();
         Calendar cal = Calendar.getInstance();
         cal.setTime(d);
         return format.format(cal.getTime());
     }
    
    
     public static void main(String args[]) {
         String Monday=getMonday("2007-05-26");
         String Sunday=getSunday("2007-05-20");
         String addDay=addDay("2007-05-20",5);
         System.out.println(Monday);
         System.out.println(Sunday);
         System.out.println(addDay);
         System.out.println(getToday());
     }
}