java获得当前日期的上个月的最后一天的日期&&每月的最大天数

// 获得当前时间所在月份的上个月的最后一天所在日期public String getLastMonthDay(Timestamp t) {        Calendar cal = Calendar.getInstance();        Date date = t;        cal.setTime(date);        int year = 0;        int month = cal.get(Calendar.MONTH); // 上个月月份       //设置年月        if (month == 0) {            year = cal.get(Calendar.YEAR) - 1;            month = 12;        } else {            year = cal.get(Calendar.YEAR);        }        //设置天数        String temp=year + "-" + month ;        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM");        Date d = null;try {d = format.parse(temp);} catch (ParseException e) {// TODO Auto-generated catch blocke.printStackTrace();}        cal.setTime(d);        int day =cal.getActualMaximum(Calendar.DAY_OF_MONTH);        String endDay = year + "-" + month + "-" + day;        return endDay;    }

//得到某月的天数public int getMonthDay(String source){//String source = "2007年12月";int count=30;SimpleDateFormat format = new SimpleDateFormat("yyyy年MM月");try {       Date date = format.parse(source);    Calendar calendar = new GregorianCalendar();      calendar.setTime(date);     count=calendar.getActualMaximum(Calendar.DAY_OF_MONTH);    }catch (Exception e) {    e.printStackTrace();   }return count;}