/**     * 获取上周周几的日期,默认一周从周一开始     * @param dayOfWeek     * @param weekOffset     * @return     */    public static Date getDayOfWeek(int dayOfWeek,int weekOffset){        return getDayOfWeek(Calendar.MONDAY,dayOfWeek,weekOffset);    }    /**     * 获取上(下)周周几的日期     * @param firstDayOfWeek {
    @link Calendar}     * 值范围 SUNDAY,     * MONDAY, TUESDAY, WEDNESDAY,     * THURSDAY, FRIDAY, and SATURDAY     * @param dayOfWeek {
    @link Calendar}     * @param weekOffset  周偏移，上周为-1，本周为0，下周为1，以此类推     * @return     */    public static Date getDayOfWeek(int firstDayOfWeek,int dayOfWeek,int weekOffset){        if(dayOfWeek>Calendar.SATURDAY || dayOfWeek
     
      Calendar.SATURDAY || firstDayOfWeek < Calendar.SUNDAY){            return null;        }        Calendar date=Calendar.getInstance(Locale.CHINA);        date.setFirstDayOfWeek(firstDayOfWeek);        //周数减一，即上周        date.add(Calendar.WEEK_OF_MONTH,weekOffset);        //日子设为周几        date.set(Calendar.DAY_OF_WEEK, dayOfWeek);        //时分秒全部置0        date.set(Calendar.HOUR_OF_DAY, 0);        date.set(Calendar.MINUTE, 0);        date.set(Calendar.SECOND, 0);        date.set(Calendar.MILLISECOND, 0);        return date.getTime();    }