Get a random time in a year interval in java

Get a random time in a year interval

The following method takes the year as an input parameter, and can return a random time in the specified year range. The returned time format is the string yyyy-mm-dd format:

 public String getRandomTime(int startYear, int endYear) throws ParseException {
        SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-mm-dd");
        //生成随机时间的年份
        int year = (int) (Math.random() * (endYear - startYear + 1)) + startYear;
        //生成随机时间的月份
        int month = (int) (Math.random() * 12) + 1;
        //使用Calendar对象确定生成的年份中的月份有多少天
        Calendar calendar = Calendar.getInstance();
        calendar.set(year, month, 0);
        int dayOfMonth = calendar.get(Calendar.DAY_OF_MONTH);
        //生成随机时间的天
        int day = (int) (Math.random() * dayOfMonth) + 1;
        //将生成的时间格式化为yyyy-mm-dd格式
        Date randomTime = dateFormat.parse(year + "-" + month + "-" + day);
        return dateFormat.format(randomTime);
    }

The test results are as follows:

Generate random times for ten [2019, 2021] year intervals:

 public static void main(String[] args) throws ParseException {
  		 for (int i=0;i<10;i++){
            String randomTime = getRandomTime(2019, 2021);
            System.out.println(randomTime);
        }
 }