Java获取本月第一天和最后一天

 public static void main(String[] args) {

        Calendar calendar = Calendar.getInstance();
        calendar.set(Calendar.HOUR_OF_DAY, 0);
        calendar.set(Calendar.MINUTE, 0);
        calendar.set(Calendar.SECOND, 0);
        calendar.add(Calendar.MONTH, -1);
        calendar.set(Calendar.DAY_OF_MONTH, 0);

        System.out.println(calendar.getTime());

        // 获取当月第一天和最后一天
        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
        String firstday, lastday;
        Calendar cale = Calendar.getInstance();

        // 获取前月的第一天
        cale = Calendar.getInstance();
        cale.add(Calendar.MONTH, 0);
        cale.set(Calendar.DAY_OF_MONTH, 1);
        firstday = format.format(cale.getTime());
        // 获取前月的最后一天
        cale = Calendar.getInstance();
        cale.add(Calendar.MONTH, 1);
        cale.set(Calendar.DAY_OF_MONTH, 0);
        lastday = format.format(cale.getTime());
        System.out.println("本月第一天和最后一天分别是 ： " + firstday + " and " + lastday);

    }

顺颂时祺