Java 日期 周 年

/**
 * java日期操作(月末、周末等的日期操作)
 * 
 * @author 
 * 
 */
public class DateUtil {
	
    /** */
    /**
     * 取得某天相加(减)後的那一天
     * 
     * @param date
     * @param num
     *            (可正可负)
     * @return
     */
    public static Date getAnotherDate(Date date, int num) {
        Calendar c = Calendar.getInstance();
        c.setTime(date);
        c.add(Calendar.DAY_OF_YEAR, num);
        return c.getTime();
    }

    /** */
    /**
     * 取得某月的的最后一天
     * 
     * @param year
     * @param month
     * @return
     */
    public static Date getLastDayOfMonth(int year, int month) {
        Calendar cal = Calendar.getInstance();
        cal.set(Calendar.YEAR, year);// 年
        cal.set(Calendar.MONTH, month - 1);// 月，因为Calendar里的月是从0开始，所以要减1
        cal.set(Calendar.DATE, 1);// 日，设为一号
        cal.add(Calendar.MONTH, 1);// 月份加一，得到下个月的一号
        cal.add(Calendar.DATE, -1);// 下一个月减一为本月最后一天
        return cal.getTime();// 获得月末是几号
    }

    /** */
    /**
     * 取得某天是一年中的多少周
     * 
     * @param date
     * @return
     */
    public static int getWeekOfYear(Date date) {
        Calendar c = new GregorianCalendar();
        c.setFirstDayOfWeek(Calendar.MONDAY);
        c.setMinimalDaysInFirstWeek(7);
        c.setTime(date);
        return c.get(Calendar.WEEK_OF_YEAR);
    }

    /** */
    /**
     * 取得某天所在周的第一天
     * 
     * @param date
     * @return
     */
    public static Date getFirstDayOfWeek(Date date) {
        Calendar c = new GregorianCalendar();
        c.setFirstDayOfWeek(Calendar.MONDAY);
        c.setTime(date);
        c.set(Calendar.DAY_OF_WEEK, c.getFirstDayOfWeek());
        return c.getTime();
    }

    /** */
    /**
     * 取得某天所在周的最后一天
     * 
     * @param date
     * @return
     */
    public static Date getLastDayOfWeek(Date date) {
        Calendar c = new GregorianCalendar();
        c.setFirstDayOfWeek(Calendar.MONDAY);
        c.setTime(date);
        c.set(Calendar.DAY_OF_WEEK, c.getFirstDayOfWeek() + 6);
        return c.getTime();
    }

    /** */
    /**
     * 取得某一年共有多少周
     * 
     * @param year
     * @return
     */
    public static int getMaxWeekNumOfYear(int year) {
        Calendar c = new GregorianCalendar();
        c.set(year, Calendar.DECEMBER, 31, 23, 59, 59);
        return getWeekOfYear(c.getTime());
    }
    /**
     * 
     * 获取某一年某一周的日期
     * @description 
     * @param year
     * @param week
     * @return
     */
    public static List<String> getWeekDays(int year,int week){
    	List<String> list = new ArrayList<String>();
    	
        Date date =  getFirstDayOfWeek(year,week);
        SimpleDateFormat d = new SimpleDateFormat("yyyy-MM-dd");
     
        for (int i = 0; i < 7; i++) {
			list.add(d.format(date));
			System.out.println(d.format(date));
		
			date.setDate(date.getDate()+1);
		}
    	return list;
    }
    /** */
    /**
     * 取得某年某周的第一天 对于交叉:2008-12-29到2009-01-04属于2008年的最后一周,2009-01-05为2009年第一周的第一天
     * 
     * @param year
     * @param week
     * @return
     */
    public static Date getFirstDayOfWeek(int year, int week) {
        Calendar calFirst = Calendar.getInstance();
        calFirst.set(year, 0, 7);
        Date firstDate = getFirstDayOfWeek(calFirst.getTime());

        Calendar firstDateCal = Calendar.getInstance();
        firstDateCal.setTime(firstDate);

        Calendar c = new GregorianCalendar();
        c.set(Calendar.YEAR, year);
        c.set(Calendar.MONTH, Calendar.JANUARY);
        c.set(Calendar.DATE, firstDateCal.get(Calendar.DATE));

        Calendar cal = (GregorianCalendar) c.clone();
        cal.add(Calendar.DATE, (week - 1) * 7);
        firstDate = getFirstDayOfWeek(cal.getTime());

        return firstDate;
    }

    /** */
    /**
     * 取得某年某周的最后一天 对于交叉:2008-12-29到2009-01-04属于2008年的最后一周, 2009-01-04为
     * 2008年最后一周的最后一天
     * 
     * @param year
     * @param week
     * @return
     */
    public static Date getLastDayOfWeek(int year, int week) {
        Calendar calLast = Calendar.getInstance();
        calLast.set(year, 0, 7);
        Date firstDate = getLastDayOfWeek(calLast.getTime());

        Calendar firstDateCal = Calendar.getInstance();
        firstDateCal.setTime(firstDate);

        Calendar c = new GregorianCalendar();
        c.set(Calendar.YEAR, year);
        c.set(Calendar.MONTH, Calendar.JANUARY);
        c.set(Calendar.DATE, firstDateCal.get(Calendar.DATE));

        Calendar cal = (GregorianCalendar) c.clone();
        cal.add(Calendar.DATE, (week - 1) * 7);
        Date lastDate = getLastDayOfWeek(cal.getTime());

        return lastDate;
    }

    /**
     *获取当前日期的年、月、日
     */
    public void display() {
        Calendar cal = Calendar.getInstance();
        // 年
        int year = cal.get(cal.YEAR);
        // 月
        int month = cal.get(cal.MONTH) + 1;
        // 日
        int date = cal.get(cal.DATE);
        // 星期
        int today = cal.get(cal.DAY_OF_WEEK) - 1;
    }
    
    
    public static void  main(String args[]){

        List<String> listWeekDate =  DateUtil.getWeekDays(2010,52);
        
        for(String weeks :listWeekDate){
			System.out.println("weeks:"+weeks);
		}
    }
}