java 根据日期获取某个月有多少天的问题

public String getDaysOfMonth(Date date) {

       Calendar calendar =Calendar.getInstance(); 

        calendar.setTime(date); 

        returncalendar.getActualMaximum(Calendar.DAY_OF_MONTH)+"";

    }

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");

Date time_end_date=sdf.parse(model.getCreate_time_end());

String endTime_end=service.getDaysOfMonth(time_end_date);

//方法2

//获取某月多少天

    public int getDaysByYearMonth(int month) {        

        Calendar a =Calendar.getInstance(); 

        //a.set(Calendar.YEAR,year); 

        a.set(Calendar.MONTH, month- 1); 

        a.set(Calendar.DATE, 1); 

        a.roll(Calendar.DATE,-1); 

        int maxDate =a.get(Calendar.DATE); 

        return maxDate; 

    }