jmeter中使用beansehell生成随机时间，并加N天

import java.time.LocalDate;
import java.time.format.DateTimeFormatter;


int max=30,min=1;
int ran2 = (int) (Math.random()*(max-min)+min);
LocalDate date_diy=LocalDate.of(2020, 11, ran2);
String ymddiy = date_diy.format(DateTimeFormatter.ofPattern("yyyy-MM-dd 00:00:00"));
String ymddiy_add7 = date_diy.plusDays(7).format(DateTimeFormatter.ofPattern("yyyy-MM-dd 00:00:00"));

vars.put("start", ymddiy); 
vars.put("end", ymddiy_add7);