DateUtil（日期工具类）

/**
     * 把日期对象根据生成指定格式的字符串
     * @param date
     * @param format
     * @return
     */
    public static String formatDate(Date date,String format){
        String result="";
        SimpleDateFormat sdf=new SimpleDateFormat(format);
        if(date!=null){
            result=sdf.format(date);
        }
        return result;
    }
    
    /**
     * 把日期字符串生成指定格式的日期对象
     * @param str
     * @param format
     * @return
     * @throws Exception
     */
    public static Date formatString(String str,String format) throws Exception{
        if(StringUtil.isEmpty(str)){
            return null;
        }
        SimpleDateFormat sdf=new SimpleDateFormat(format);
        return sdf.parse(str);
    }
    
    /**
     * 生成当前年月日字符串
     * @return
     * @throws Exception
     */
    public static String getCurrentDateStr()throws Exception{
        Date date=new Date();
        SimpleDateFormat sdf=new SimpleDateFormat("yyyyMMdd");
        return sdf.format(date);
    }
    
    /**
     * 获取指定范围内的日期集合
     * @param before
     * @param end
     * @return
     * @throws Exception
     */
    public static List<String> getRangeDates(String before,String end)throws Exception{
        List<String> datas=new ArrayList<String>();
        Calendar cb = Calendar.getInstance();
        Calendar ce = Calendar.getInstance();
        cb.setTime(formatString(before,"yyyy-MM-dd"));
        ce.setTime(formatString(end,"yyyy-MM-dd"));
        datas.add(formatDate(cb.getTime(),"yyyy-MM-dd"));
        while(cb.before(ce)){
            cb.add(Calendar.DAY_OF_MONTH, 1);
            datas.add(formatDate(cb.getTime(),"yyyy-MM-dd"));
        }
        return datas;
    }
    
    /**
     * 获取指定范围内的月份集合
     * @param before
     * @param end
     * @return
     * @throws Exception
     */
    public static List<String> getRangeMonth(String before,String end)throws Exception{
        List<String> months=new ArrayList<String>();
        Calendar cb = Calendar.getInstance();
        Calendar ce = Calendar.getInstance();
        cb.setTime(formatString(before,"yyyy-MM"));
        ce.setTime(formatString(end,"yyyy-MM"));
        months.add(formatDate(cb.getTime(),"yyyy-MM"));
        while(cb.before(ce)){
            cb.add(Calendar.MONTH, 1);
            months.add(formatDate(cb.getTime(),"yyyy-MM"));
        }
        return months;
    }
    
    
    public static void main(String[] args) throws Exception{
        /*List<String> datas=getRangeDatas("2017-10-28","2017-11-02");
        for(String data:datas){
            System.out.println(data);
        }*/
        List<String> months=getRangeMonth("2017-09","2018-12");
        for(String month:months){
            System.out.println(month);
        }
    }