java实现对数据库日期天数的处理

public static void main(String[] args) throws ParseException {

String str = "yyyy-MM-dd 00:00:00.0";
String str1 = str.substring(0, 10);
/*
* 将yyyy-1-1转换成yyyy-01-01
*/
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Date date = sdf.parse(str1);
String str2 = sdf.format(date);
String year = str2.substring(0, 4);
String month = str2.substring(5, 7);
String day = str2.substring(8, 10);
Calendar c = Calendar.getInstance();
c.set(Integer.parseInt(year), Integer.parseInt(month), Integer
.parseInt(day));

/*
* 日期加1，如开始是yyyy年1月1日，处理后就是yyyy年1月2日
*/
c.add(Calendar.DAY_OF_MONTH, 1);
year = Integer.toString(c.get(Calendar.YEAR));
month = Integer.toString(c.get(Calendar.MONTH));
day = Integer.toString(c.get(Calendar.DATE));
String newDate = year + "-" + month + "-" + day;
System.out.println(newDate);
}